Inbreeding affects sexual signalling in males but not females of Tenebrio molitor

PubMed Central

Pölkki, Mari; Krams, Indrikis; Kangassalo, Katariina; Rantala, Markus J.

2012-01-01

In many species of animals, individuals advertise their quality with sexual signals to obtain mates. Chemical signals such as volatile pheromones are species specific, and their primary purpose is to influence mate choice by carrying information about the phenotypic and genetic quality of the sender. The deleterious effects of consanguineous mating on individual quality are generally known, whereas the effect of inbreeding on sexual signalling is poorly understood. Here, we tested whether inbreeding reduces the attractiveness of sexual signalling in the mealworm beetle, Tenebrio molitor, by testing the preferences for odours of inbred and outbred (control) individuals of the opposite sex. Females were more attracted to the odours produced by outbred males than the odours produced by inbred males, suggesting that inbreeding reduces the attractiveness of male sexual signalling. However, we did not find any difference between the attractiveness of inbred and outbred female odours, which may indicate that the quality of females is either irrelevant for T. molitor males or quality is not revealed through female odours. PMID:22237501

Insights into the role of age and social interactions on the sexual attractiveness of queens in an eusocial bee, Melipona flavolineata (Apidae, Meliponini).

PubMed

Veiga, Jamille Costa; Menezes, Cristiano; Contrera, Felipe Andrés León

2017-04-01

The attraction of sexual partners is a vital necessity among insects, and it involves conflict of interests and complex communication systems among male and female. In this study, we investigated the developing of sexual attractiveness in virgin queens (i.e., gynes) of Melipona flavolineata, an eusocial stingless bee. We followed the development of sexual attractiveness in 64 gynes, belonging to seven age classes (0, 3, 6, 9, 15, 18 days post-emergence), and we also evaluated the effect of different social interactions (such as competition between queens and interactions with workers) on the development of attractiveness in other 60 gynes. We used the number of males that tried to mate with a focal gyne as a representative variable of its sexual attractiveness. During the essays, each gyne was individually presented to 10 sexually mature males, and during 3 min, we counted the number of males that everted their genitalia in response to the presence of a gyne. Here, we show that M. flavolineata gynes are capable to (i) maintain their sexual attractiveness for long periods through adult life, (ii) they need a minimum social interaction to trigger the development of sexual attractiveness, and (iii) that gynes express this trait only within a social context. We conclude that the effective occurrence of matings is conditional on potential social interactions that gynes experienced before taking the nuptial flight, when they are still in the nest. These findings bring insights into the factors determining reproductive success in social insects.

Insights into the role of age and social interactions on the sexual attractiveness of queens in an eusocial bee, Melipona flavolineata (Apidae, Meliponini)

NASA Astrophysics Data System (ADS)

Veiga, Jamille Costa; Menezes, Cristiano; Contrera, Felipe Andrés León

2017-04-01

The attraction of sexual partners is a vital necessity among insects, and it involves conflict of interests and complex communication systems among male and female. In this study, we investigated the developing of sexual attractiveness in virgin queens (i.e., gynes) of Melipona flavolineata, an eusocial stingless bee. We followed the development of sexual attractiveness in 64 gynes, belonging to seven age classes (0, 3, 6, 9, 15, 18 days post-emergence), and we also evaluated the effect of different social interactions (such as competition between queens and interactions with workers) on the development of attractiveness in other 60 gynes. We used the number of males that tried to mate with a focal gyne as a representative variable of its sexual attractiveness. During the essays, each gyne was individually presented to 10 sexually mature males, and during 3 min, we counted the number of males that everted their genitalia in response to the presence of a gyne. Here, we show that M. flavolineata gynes are capable to (i) maintain their sexual attractiveness for long periods through adult life, (ii) they need a minimum social interaction to trigger the development of sexual attractiveness, and (iii) that gynes express this trait only within a social context. We conclude that the effective occurrence of matings is conditional on potential social interactions that gynes experienced before taking the nuptial flight, when they are still in the nest. These findings bring insights into the factors determining reproductive success in social insects.

Sexual behavior of gender-dysphoric individuals before gender-confirming interventions: a European multicenter study.

PubMed

Cerwenka, Susanne; Nieder, Timo O; Cohen-Kettenis, Peggy; De Cuypere, Griet; Haraldsen, Ira R Hebold; Kreukels, Baudewijntje P C; Richter-Appelt, Hertha

2014-01-01

A transsexual course of development that starts before puberty (early onset) or during or after puberty, respectively (late onset), may lead to diverse challenges in coping with sexual activity. The authors explored the sexual behavior of 380 adult male-to-female and female-to-male individuals diagnosed according to DSM-IV-TR criteria who had not yet undergone gender-confirming interventions. Data originated from the European Network for the Investigation of Gender Incongruence Initiative, conducted in Belgium, Germany, The Netherlands, and Norway. Information on outcome variables was collected using self-administered questionnaires at first clinical presentation. Compared with late-onset male-to-females, early-onset individuals tended to show sexual attraction toward males more frequently (50.5%), involve genitals less frequently in partner-related sexual activity, and consider penile sensations and orgasm as more negative. Early-onset female-to-males predominantly reported sexual attraction toward females (84.0%), whereas those with a late-onset more frequently showed other sexual attractions (41.7%). The study (a) shows that early- and late-onset male-to-females differ considerably with regard to coping strategies involving their body during sexual relations and (b) reveals initial insights into developmental pathways of late-onset female-to-males.

Gendered sexuality: a new model and measure of attraction and intimacy.

PubMed

Starks, Tyrel J; Gilbert, Brenda O; Fischer, Ann R; Weston, Rebecca; DiLalla, David L

2009-01-01

Currently, the literature related to sexual orientation is ambiguous with regard to the relationship of sexual orientation, sexual identity, attraction, and intimacy. In order to explore the relationships of self-identified categorical sexual identity (which is the most popular method of sexual orientation assessment) with attraction and intimacy, it is imperative that researchers have access to a reliable and valid measure of the latter. The present study proposes a model for conceptualizing attraction and intimacy, termed gendered sexuality, and examines the factor structure of a measure designed to assess the construct. Results suggest that four factors adequately accounted for the variance in gendered sexuality in a large sample of young adults. These factors assess attraction to females, attraction to males, intimacy with females, and intimacy with males. Exploratory analyses provided preliminary evidence of potential construct validity and suggested that discrepancies between desired and available behavior predict dissatisfaction in interpersonal role as measured by the Outcome Questionnaire 45.2.

Effects of sexual dimorphism on facial attractiveness.

PubMed

Perrett, D I; Lee, K J; Penton-Voak, I; Rowland, D; Yoshikawa, S; Burt, D M; Henzi, S P; Castles, D L; Akamatsu, S

1998-08-27

Testosterone-dependent secondary sexual characteristics in males may signal immunological competence and are sexually selected for in several species. In humans, oestrogen-dependent characteristics of the female body correlate with health and reproductive fitness and are found attractive. Enhancing the sexual dimorphism of human faces should raise attractiveness by enhancing sex-hormone-related cues to youth and fertility in females, and to dominance and immunocompetence in males. Here we report the results of asking subjects to choose the most attractive faces from continua that enhanced or diminished differences between the average shape of female and male faces. As predicted, subjects preferred feminized to average shapes of a female face. This preference applied across UK and Japanese populations but was stronger for within-population judgements, which indicates that attractiveness cues are learned. Subjects preferred feminized to average or masculinized shapes of a male face. Enhancing masculine facial characteristics increased both perceived dominance and negative attributions (for example, coldness or dishonesty) relevant to relationships and paternal investment. These results indicate a selection pressure that limits sexual dimorphism and encourages neoteny in humans.

Supplementation of Male Pheromone on Rock Substrates Attracts Female Rock Lizards to the Territories of Males: A Field Experiment

PubMed Central

Martín, José; López, Pilar

2012-01-01

Background Many animals produce elaborated sexual signals to attract mates, among them are common chemical sexual signals (pheromones) with an attracting function. Lizards produce chemical secretions for scent marking that may have a role in sexual selection. In the laboratory, female rock lizards (Iberolacerta cyreni) prefer the scent of males with more ergosterol in their femoral secretions. However, it is not known whether the scent-marks of male rock lizards may actually attract females to male territories in the field. Methodology/Principal Findings In the field, we added ergosterol to rocks inside the territories of male lizards, and found that this manipulation resulted in increased relative densities of females in these territories. Furthermore, a higher number of females were observed associated to males in manipulated plots, which probably increased mating opportunities for males in these areas. Conclusions/Significance These and previous laboratory results suggest that female rock lizards may select to settle in home ranges based on the characteristics of scent-marks from conspecific males. Therefore, male rock lizards might attract more females and obtain more matings by increasing the proportion of ergosterol when scent-marking their territories. However, previous studies suggest that the allocation of ergosterol to secretions may be costly and only high quality males could afford it, thus, allowing the evolution of scent-marks as an honest sexual display. PMID:22253895

Relationship between Sexual Harassment, Initiator Attractiveness, and Pro-Feminist Attitudes.

ERIC Educational Resources Information Center

Wheeler, R. Wade; And Others

Research has shown that physically attractive people in this culture are treated more favorably than are unattractive people. If this is so, acts of sexual harassment perpetrated by attractive males might be viewed less harshly than the same acts perpetrated by unattractive males. A study was conducted to examine the relationshp between…

Women's hormone levels modulate the motivational salience of facial attractiveness and sexual dimorphism.

PubMed

Wang, Hongyi; Hahn, Amanda C; Fisher, Claire I; DeBruine, Lisa M; Jones, Benedict C

2014-12-01

The physical attractiveness of faces is positively correlated with both behavioral and neural measures of their motivational salience. Although previous work suggests that hormone levels modulate women's perceptions of others' facial attractiveness, studies have not yet investigated whether hormone levels also modulate the motivational salience of facial characteristics. To address this issue, we investigated the relationships between within-subject changes in women's salivary hormone levels (estradiol, progesterone, testosterone, and estradiol-to-progesterone ratio) and within-subject changes in the motivational salience of attractiveness and sexual dimorphism in male and female faces. The motivational salience of physically attractive faces in general and feminine female faces, but not masculine male faces, was greater in test sessions where women had high testosterone levels. Additionally, the reward value of sexually dimorphic faces in general and attractive female faces, but not attractive male faces, was greater in test sessions where women had high estradiol-to-progesterone ratios. These results provide the first evidence that the motivational salience of facial attractiveness and sexual dimorphism is modulated by within-woman changes in hormone levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Endorsement and Timing of Sexual Orientation Developmental Milestones Among Sexual Minority Young Adults in the Growing Up Today Study.

PubMed

Katz-Wise, Sabra L; Rosario, Margaret; Calzo, Jerel P; Scherer, Emily A; Sarda, Vishnudas; Austin, S Bryn

2017-02-01

This research examined endorsement and timing of sexual orientation developmental milestones. Participants were 1,235 females and 398 males from the Growing Up Today Study, ages 22 to 29 years, who endorsed a sexual minority orientation (lesbian/gay, bisexual, mostly heterosexual) or reported same-gender sexual behavior (heterosexual with same-gender sexual experience). An online survey measured current sexual orientation and endorsement and timing (age first experienced) of five sexual orientation developmental milestones: same-gender attractions, other-gender attractions, same-gender sexual experience, other-gender sexual experience, and sexual minority identification. Descriptive analyses and analyses to test for gender and sexual orientation group differences were conducted. Results indicated that women were more likely than men to endorse same-gender attraction, other-gender attraction, and other-gender sexual experience, with the most gender differences in endorsement among mostly heterosexuals and heterosexuals with same-gender sexual experience. In general, men reached milestones earlier than women, with the most gender differences in timing among lesbian and gay individuals and heterosexuals with same-gender sexual experience. Results suggest that the three sexual minority developmental milestones may best characterize the experiences of lesbians, gay males, and female and male bisexuals. More research is needed to understand sexual orientation development among mostly heterosexuals and heterosexuals with same-gender sexual experience.

Sensation in a single neuron pair represses male behavior in hermaphrodites

PubMed Central

White, Jamie Q.; Jorgensen, Erik M.

2012-01-01

Summary Pheromones elicit innate sex-specific mating behaviors in many species. We demonstrate that in C. elegans, male-specific sexual attraction behavior is programmed in both sexes but repressed in hermaphrodites. Repression requires a single sensory neuron pair, the ASIs. To represses attraction in adults, the ASIs must be present, active, and capable of sensing the environment during development. The ASIs release TGF-β, and ASI function can be bypassed by experimental activation of TGF-β signaling. Sexual attraction in de-repressed hermaphrodites requires the same sensory neurons as in males. The sexual identity of both these sensory neurons and a distinct subset of interneurons must be male to relieve repression and release attraction. TGF-β may therefore act to change connections between sensory- and interneurons during development to engage repression. Thus, sensation in a single sensory neuron pair during development reprograms a common neural circuit from male to female behavior. PMID:22920252

Young Sexual Minority Males in the United States: Sociodemographic Characteristics And Sexual Attraction, Identity and Behavior.

PubMed

Fasula, Amy M; Oraka, Emeka; Jeffries, William L; Carry, Monique; Bañez Ocfemia, M Cheryl; Balaji, Alexandra B; Rose, Charles E; Jayne, Paula E

2016-03-01

HIV incidence is increasing among 13-24-year-old U.S. men who have sex with men, yet limited research is available to guide HIV prevention efforts for this population. National Survey of Family Growth data collected in 2002, in 2006-2010 and in 2011-2013 from 8,068 males aged 15-24 were analyzed to describe the population of U.S. young sexual minority males (i.e., males reporting same-sex attraction, identity or behavior). Correlates of sexual minority classification were assessed in logistic regression models. An estimated 10% of young males, representing a population of 2.1 million, were sexual minorities. Males had an elevated likelihood of being sexual minorities if they were aged 18-19 or 20-24, rather than 15-17 (prevalence ratio, 1.7 for each); belonged to nonblack, non-Hispanic racial or ethnic minority groups (1.6); had no religious affiliation, rather than considering religion very important (1.9); or lived below the federal poverty level (1.3). They had a reduced likelihood of being sexual minorities if they lived in metropolitan areas outside of central cities (0.7). Among young sexual minority males, 44% were 15-19 years old, 29% were poor and 59% resided outside central cities. Forty-seven percent had engaged in same-sex behavior. Of those with data on all measured dimensions of sexuality, 24% reported same-sex attraction, identity and behavior; 22% considered themselves heterosexual, yet had had a male sex partner. Future investigations can further explore subpopulations of young sexual minority males and assess sexual trajectories, resilience and HIV risk. Copyright © 2016 by the Guttmacher Institute.

Moral Judgments on Short-Term Sexual Behaviors among Chinese College Students: Exploring the Roles of Gender and Physical Attractiveness.

PubMed

Xiao, Qianguo; Li, Aijuan; Zhu, Yi

2017-01-01

This study primarily investigated the effects of gender and physical attractiveness on moral judgments on three typical kinds of short-term sexual behaviors (short-term fling, one-night stand, and hookup) in the Chinese culture context. A total of 120 university student subjects were presented with a series of stereotypically physically attractive (versus physically unattractive) photos before they rated the extent to which each of the three short-term sexual behaviors are morally acceptable. The results showed that male students judged all three behaviors to be more morally acceptable than female students did. Further analyses showed that this gender difference was moderated by the level of physical attractiveness. Under the high attractiveness condition, short-term flings and hookups were judged more morally acceptable by male students than by female students, but this gender difference was not significant under the low attractiveness condition. However, with regard to one-night stands, the data showed that male students judged this type of behavior to be more morally acceptable than did female students under the low attractiveness condition, while this gender difference was not significant under the high attractiveness condition. Thus, these findings further our understanding of how Chinese young people view different types of short-term sexual behaviors, and provide novel evidence regarding how physical attractiveness influences people's moral judgments on short-term sexual behaviors.

Moral Judgments on Short-Term Sexual Behaviors among Chinese College Students: Exploring the Roles of Gender and Physical Attractiveness

PubMed Central

Xiao, Qianguo; Li, Aijuan; Zhu, Yi

2017-01-01

This study primarily investigated the effects of gender and physical attractiveness on moral judgments on three typical kinds of short-term sexual behaviors (short-term fling, one-night stand, and hookup) in the Chinese culture context. A total of 120 university student subjects were presented with a series of stereotypically physically attractive (versus physically unattractive) photos before they rated the extent to which each of the three short-term sexual behaviors are morally acceptable. The results showed that male students judged all three behaviors to be more morally acceptable than female students did. Further analyses showed that this gender difference was moderated by the level of physical attractiveness. Under the high attractiveness condition, short-term flings and hookups were judged more morally acceptable by male students than by female students, but this gender difference was not significant under the low attractiveness condition. However, with regard to one-night stands, the data showed that male students judged this type of behavior to be more morally acceptable than did female students under the low attractiveness condition, while this gender difference was not significant under the high attractiveness condition. Thus, these findings further our understanding of how Chinese young people view different types of short-term sexual behaviors, and provide novel evidence regarding how physical attractiveness influences people’s moral judgments on short-term sexual behaviors. PMID:28243218

Sexual attraction enhances glutamate transmission in mammalian anterior cingulate cortex

PubMed Central

Wu, Long-Jun; Kim, Susan S; Li, Xiangyao; Zhang, Fuxing; Zhuo, Min

2009-01-01

Functional human brain imaging studies have indicated the essential role of cortical regions, such as the anterior cingulate cortex (ACC), in romantic love and sex. However, the neurobiological basis of how the ACC neurons are activated and engaged in sexual attraction remains unknown. Using transgenic mice in which the expression of green fluorescent protein (GFP) is controlled by the promoter of the activity-dependent gene c-fos, we found that ACC pyramidal neurons are activated by sexual attraction. The presynaptic glutamate release to the activated neurons is increased and pharmacological inhibition of neuronal activities in the ACC reduced the interest of male mice to female mice. Our results present direct evidence of the critical role of the ACC in sexual attraction, and long-term increases in glutamate mediated excitatory transmission may contribute to sexual attraction between male and female mice. PMID:19419552

Women's motivations to have sex in casual and committed relationships with male and female partners.

PubMed

Armstrong, Heather L; Reissing, Elke D

2015-05-01

Women report a wide variety of reasons to have sex (e.g., Meston & Buss, 2010), and while it is reasonable to assume that those reasons may vary based on the context of the relationship, this assumption has not yet been tested. The purpose of this study was to explore how relationship type, sexual attraction, and the gender of one's partner interact and affect the sexual motivations of women. A total of 510 women (361 who reported exclusively other-sex attraction and 149 who reported same-sex/bisexual attraction) completed the YSEX? questionnaire. Participants rated their sexual motivations for casual sex and sex in a committed relationship with male and/or female partners, depending on reported sexual attraction. Results showed that relationship type affected reported motivation for sex: physical motivations were more strongly endorsed for casual sex, whereas emotional motivations were more strongly endorsed for sex in committed relationships. No significant differences in motivation were reported between women who reported same-sex attraction and those who did not. Women who reported bisexual attraction and identified as being lesbian, bisexual, or another sexual minority reported no significant differences in motivation for sex with male or female partners. The results of this study highlight the importance of relationship context when discussing sexual motivation and suggest a high degree of similarity in motivation for women, regardless of sexual orientation or gender of partner.

Lack of differences between males with or without perceived same sex attraction.

PubMed

Lee, Peter A; Houk, Christopher P

2006-02-01

Adolescent males are often concerned that they may be homosexual because of a sense of sexual attraction to other males. This not uncommon concern is often expressed to pediatric endocrinologists who come into contact with these boys because of concerns with abnormal pubertal development. To explore the character and prevalence of these types of homosexual concerns we assessed the perceptions of a group of healthy adolescent males using a structured questionnaire. The aim of this study was to determine whether males concerned about homosexual tendencies manifest a unique self-perception profile or interact differently with others. A multi-item questionnaire regarding demographic, behavioral, psychological and sexual characteristics was administered to 52 18-24 year-old males. Overall, there were few differences between males admitting to an adolescent homosexual attraction to males and males without this attraction. Differences between these two groups included more exposure to some kinds of pornography (including male to male imagery), noticeable psychosexual responses to male pornography, internal questioning over homosexual tendencies, comparisons of genitalia and perceptions of body build. There were no differences in demographics, family structure, religious beliefs, socio-economic status, knowledge of puberty, inter-personal relationships or sources of information about sexuality.

Visual Attention Patterns of Women with Androphilic and Gynephilic Sexual Attractions.

PubMed

Dawson, Samantha J; Fretz, Katherine M; Chivers, Meredith L

2017-01-01

Women who report exclusive sexual attractions to men (i.e., androphilia) exhibit gender-nonspecific patterns of sexual response-similar magnitude of genital response to both male and female targets. Interestingly, women reporting any degree of attraction to women (i.e., gynephilia) show significantly greater sexual responses to stimuli depicting female targets compared to male targets. At present, the mechanism(s) underlying these patterns are unknown. According to the information processing model (IPM), attentional processing of sexual cues initiates sexual responding; thus, attention to sexual cues may be one mechanism to explain the observed within-gender differences in specificity findings among women. The purpose of the present study was to examine patterns of initial and controlled visual attention among women with varying sexual attractions. We used eye tracking to assess visual attention to sexually preferred and nonpreferred cues in a sample of 164 women who differed in their degree of androphilia and gynephilia. We found that both exclusively and predominantly androphilic women showed gender-nonspecific patterns of initial attention. In contrast, ambiphilic (i.e., concurrent androphilia and gynephilia) and predominantly/exclusively gynephilic women oriented more quickly toward female targets. Controlled attention patterns mirrored patterns of self-reported sexual attractions for three of these four groups of women, such that gender-specific patterns of visual attention were found for androphilic and gynephilic women. Ambiphilic women looked significantly longer at female targets compared to male targets. These findings support predictions from the IPM and suggest that both initial and controlled attention to sexual cues may be mechanisms contributing to within-gender variation in sexual responding.

Inter- and intraspecific sexual discrimination in the flour beetles Tribolium castaneum and Tribolium confusum.

PubMed

Serrano, J M; Castro, L; Toro, M A; López-Fanjul, C

2000-08-01

In Tribolium castaneum (CS) and T. confusum (CF), intra- and interspecific rates of homosexual mounting have been measured. The intraspecific results are compatible with the hypothesis of both species being sexually indiscriminate. However, the CF intraspecific rates were very high (35%-53% of mountings were homosexual), suggesting a lower sexual attractiveness, or a stronger rejection to being mounted, of CF females relative to conspecific males. CS males discriminate between species but, in interspecific contacts, preferentially mounted CF males rather than CF females. CF males do not discriminate between species, but the loss of sexual attractiveness of CF females, or their rejection to being mounted, may act as a precopulatory isolation mechanism.

Protozoan Parasite Toxoplasma gondii Manipulates Mate Choice in Rats by Enhancing Attractiveness of Males

PubMed Central

Dutta, Deborah; Soh, Linda Jing Ting; Sapolsky, Robert Morris; Vyas, Ajai

2011-01-01

Females in various species typically avoid males infected with parasites, while parasite-free males advertise their status through conspicuous phenotypic traits. This process selects for heritable resistance and reduces direct exposure of the female to parasites. Coevolving parasites are likely to attempt to circumvent this obstacle. In this paper, we demonstrate a case of parasitic manipulation of host mate choice. We report that Toxoplasma gondii, a sexually transmitted infection of brown rats, enhances sexual attractiveness of infected males. Thus under some evolutionary niches, parasites can indeed manipulate host sexual signaling to their own advantage. PMID:22073295

Sublethal exposure to methoxyfenozide-treated surfaces reduces the attractiveness and responsiveness in adult oriental fruit moth (Lepidoptera: Tortricidae).

PubMed

Reinke, Michael D; Barrett, Bruce A

2007-02-01

The chemical communication (female attractiveness and male responsiveness) of adult oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), exposed to surfaces treated with the ecdysteroid agonist methoxyfenozide for 48 h were investigated in two laboratory wind tunnel assays. The recapture assay examined the ability of treated males to orient to a single cage of treated females, and the data gathered were mean percentage of males recaptured per treatment. The male sexual behavior assay examined some specific orientation behaviors (associated with sexual excitability) of treated males when they were given a choice of two competing pheromone sources (cages of treated females), and the data gathered were mean time males spent in upwind plume orientations and at source contact (female cage) per treatment. Data from the recapture assay suggests that exposure to methoxyfenozide impacts male responsiveness more than female attractiveness. In contrast, data from the sexual behavior assay strongly revealed that exposure to methoxyfenozide-treated surfaces does negatively impact both the ability of calling females to attract males and of aroused males to display sustained upwind flight behavior and time spent at the female cages.

Penis size interacts with body shape and height to influence male attractiveness.

PubMed

Mautz, Brian S; Wong, Bob B M; Peters, Richard A; Jennions, Michael D

2013-04-23

Compelling evidence from many animal taxa indicates that male genitalia are often under postcopulatory sexual selection for characteristics that increase a male's relative fertilization success. There could, however, also be direct precopulatory female mate choice based on male genital traits. Before clothing, the nonretractable human penis would have been conspicuous to potential mates. This observation has generated suggestions that human penis size partly evolved because of female choice. Here we show, based upon female assessment of digitally projected life-size, computer-generated images, that penis size interacts with body shape and height to determine male sexual attractiveness. Positive linear selection was detected for penis size, but the marginal increase in attractiveness eventually declined with greater penis size (i.e., quadratic selection). Penis size had a stronger effect on attractiveness in taller men than in shorter men. There was a similar increase in the positive effect of penis size on attractiveness with a more masculine body shape (i.e., greater shoulder-to-hip ratio). Surprisingly, larger penis size and greater height had almost equivalent positive effects on male attractiveness. Our results support the hypothesis that female mate choice could have driven the evolution of larger penises in humans. More broadly, our results show that precopulatory sexual selection can play a role in the evolution of genital traits.

Brief Report: Sexual Attraction and Relationships in Adolescents with Autism

ERIC Educational Resources Information Center

May, Tamara; Pang, Ken C.; Williams, Katrina

2017-01-01

Past research suggests more variation in sexual attraction in Autism Spectrum Disorder (ASD) using clinical samples. This study utilised a population representative group of 14/15 year olds from the Longitudinal Study of Australian Children. Ninety-four adolescents (73 males, 21 females) with ASD and 3454 (1685 males, 1675 females) without…

"Nice guys finish last": influence of mate choice on reproductive success in Long-Evans rats.

PubMed

Winland, C; Bolton, J L; Ford, B; Jampana, S; Tinker, J; Frohardt, R J; Guarraci, F A; Zewail-Foote, M

2012-02-01

The present study was designed to determine if male physiology and male reproductive behavior predict reproductive success in Long-Evans rats. Mating behavior was observed in sexually naïve, naturally cycling female rats during behavioral estrous that were given the opportunity to mate with two males simultaneously. DNA analysis of offspring born following these mating encounters was used to identify the paternity of each pup. In order to assess the effect of mate choice during these mating encounters on reproductive success, one male rat in each pair was categorized as the preferred mate if the female spent more time (>50%) with him during the mating test of the present study. Furthermore, each male in the pairs was categorized as "attractive" or "non-attractive" by computing the number of females that preferred each male across many mating tests. Similar to results reported in Lovell et al. (2007), during 76% of these mating tests the same male rat in each pair was preferred by different female rats. Overall attractiveness of individual male rats predicted reproductive success in the present study. Interestingly, "attractive" males sired significantly FEWER pups than "non-attractive" males. Neither behavioral (e.g., latency to first sexual stimulation, number of sexual stimulations) nor physiological measures (e.g., body weight, urinary testosterone levels) of male rats predicted their reproductive success. In conclusion, the present results indicate that certain features of some males are more attractive to females, but attractive males are at a reproductive disadvantage (as measured by the number of pups sired). Although basal urinary testosterone levels did not differ between males that sired the majority of pups in a litter and males that sired few or none of the pups in a litter, aggression and/or other physiological measures of fertility (e.g., penile reflexes) may differ between males that are attractive to females and those that have a reproductive advantage. Copyright © 2011 Elsevier Inc. All rights reserved.

Chemosignalling effects of human tears revisited: Does exposure to female tears decrease males' perception of female sexual attractiveness?

PubMed

Gračanin, Asmir; van Assen, Marcel A L M; Omrčen, Višnja; Koraj, Ivana; Vingerhoets, Ad J J M

2017-01-01

Gelstein et al. reported the results of three experiments suggesting a dampening influence of inhalation of female emotional tears on males' arousal and perception of female sexual attractiveness, specifically in non-sexual situations. This prompted the hypothesis that crying exerts its influence on others not only via the auditory and visual mode but also via chemosignals. In three studies, we attempted to replicate and extend Gelstein et al.'s findings by including an additional condition with irritant tears, by using pictures of sexually attractive women, and by testing related hypotheses on the pro-social effects of exposure to tears. All three studies, separately or combined in a meta-analysis, failed to replicate the original inhibitory effects of tears. In addition, sniffing tears did not affect measures of connectedness, aggression and pro-social behaviour. It is concluded that the effects of female tears on male arousal and perception of female sexual attractiveness, if any, are very weak at best. Rather, it seems that crying exerts its strong inter-personal effects through the visual and auditory sensory channels.

Hemiclonal analysis of interacting phenotypes in male and female Drosophila melanogaster

PubMed Central

2014-01-01

Background Identifying the sources of variation in mating interactions between males and females is important because this variation influences the strength and/or the direction of sexual selection that populations experience. While the origins and effects of variation in male attractiveness and ornamentation have received much scrutiny, the causes and consequences of intraspecific variation in females have been relatively overlooked. We used cytogenetic cloning techniques developed for Drosophila melanogaster to create “hemiclonal” males and females with whom we directly observed sexual interaction between individuals of different known genetic backgrounds and measured subsequent reproductive outcomes. Using this approach, we were able to quantify the genetic contribution of each mate to the observed phenotypic variation in biologically important traits including mating speed, copulation duration, and subsequent offspring production, as well as measure the magnitude and direction of intersexual genetic correlation between female choosiness and male attractiveness. Results We found significant additive genetic variation contributing to mating speed that can be attributed to male genetic identity, female genetic identity, but not their interaction. Furthermore we found that phenotypic variation in copulation duration had a significant male-associated genetic component. Female genetic identity and the interaction between male and female genetic identity accounted for a substantial amount of the observed phenotypic variation in egg size. Although previous research predicts a trade-off between egg size and fecundity, this was not evident in our results. We found a strong negative genetic correlation between female choosiness and male attractiveness, a result that suggests a potentially important role for sexually antagonistic alleles in sexual selection processes in our population. Conclusion These results further our understanding of sexual selection because they identify that genetic identity plays a significant role in phenotypic variation in female behaviour and fecundity. This variation may be potentially due to ongoing sexual conflict found between the sexes for interacting phenotypes. Our unexpected observation of a negative correlation between female choosiness and male attractiveness highlights the need for more explicit theoretical models of genetic covariance to investigate the coevolution of female choosiness and male attractiveness. PMID:24884361

Preferences for masculinity in male bodies change across the menstrual cycle.

PubMed

Little, Anthony C; Jones, Benedict C; Burriss, Robert P

2007-05-01

In human females cyclic shifts in preference have been documented for odour and physical and behavioral male traits. Women prefer the smell of dominant males, more masculine male faces and men behaving more dominantly when at peak fertility than at other times in their menstrual cycle. Here we examine variation in preferences for body sexual dimorphism. Across two studies, both between- and within-participant, we show that women prefer greater masculinity in male bodies at times when their fertility is likely highest, in the follicular phase of their cycle. Shifts were seen when rating for a short-term but not when rating for a long-term relationship. In line with studies showing similar effects for facial sexual dimorphism, we also show that women prefer greater masculinity when they think themselves attractive than when they think themselves less attractive. These results indicate that women's preferences for sexual dimorphism in male bodies follow a similar pattern as found for sexual dimorphism and dominance in other domains and such differences in preference may serve a similar function. Cyclic preferences could influence women to select partners when most likely to become pregnant that possess traits that may be most likely to maximize their offspring's quality via attraction to masculinity or serve to help acquire investment via attraction to femininity.

Sexual conflict over mating in Gnatocerus cornutus? Females prefer lovers not fighters.

PubMed

Okada, Kensuke; Katsuki, Masako; Sharma, Manmohan D; House, Clarissa M; Hosken, David J

2014-06-22

Female mate choice and male-male competition are the typical mechanisms of sexual selection. However, these two mechanisms do not always favour the same males. Furthermore, it has recently become clear that female choice can sometimes benefit males that reduce female fitness. So whether male-male competition and female choice favour the same or different males, and whether or not females benefit from mate choice, remain open questions. In the horned beetle, Gnatocerus cornutus, males have enlarged mandibles used to fight rivals, and larger mandibles provide a mating advantage when there is direct male-male competition for mates. However, it is not clear whether females prefer these highly competitive males. Here, we show that female choice targets male courtship rather than mandible size, and these two characters are not phenotypically or genetically correlated. Mating with attractive, highly courting males provided indirect benefits to females but only via the heritability of male attractiveness. However, mating with attractive males avoids the indirect costs to daughters that are generated by mating with competitive males. Our results suggest that male-male competition may constrain female mate choice, possibly reducing female fitness and generating sexual conflict over mating.

Reproductive strategy, sexual development and attraction to facial characteristics

PubMed Central

Cornwell, R. Elisabeth; Law Smith, Miriam J; Boothroyd, Lynda G; Moore, Fhionna R; Davis, Hasker P; Stirrat, Michael; Tiddeman, Bernard; Perrett, David I

2006-01-01

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics. PMID:17118929

Reproductive strategy, sexual development and attraction to facial characteristics.

PubMed

Cornwell, R Elisabeth; Law Smith, Miriam J; Boothroyd, Lynda G; Moore, Fhionna R; Davis, Hasker P; Stirrat, Michael; Tiddeman, Bernard; Perrett, David I

2006-12-29

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics.

The ovine sexually dimorphic nucleus, aromatase, and sexual partner preferences in sheep.

PubMed

Roselli, C E; Stormshak, F

2010-02-28

We are using the domestic ram as an experimental model to examine the role of aromatase in the development of sexual partner preferences. This interest has arisen because of the observation that as many as 8% of domestic rams are sexually attracted to other rams (male-oriented) in contrast to the majority of rams that are attracted to estrous ewes (female-oriented). Our findings demonstrate that aromatase expression is enriched in a cluster of neurons in the medial preoptic nucleus called the ovine sexually dimorphic nucleus (oSDN). The size of the oSDN is associated with a ram's sexual partner preference, such that the nucleus is 2-3 times larger in rams that are attracted to females (female-oriented) than in rams that are attracted to other rams (male-oriented). Moreover, the volume of the oSDN in male-oriented rams is similar to the volume in ewes. These volume differences are not influenced by adult concentrations of serum testosterone. Instead, we found that the oSDN is already present in late gestation lamb fetuses (approximately day 135 of gestation) when it is approximately 2-fold greater in males than in females. Exposure of genetic female fetuses to exogenous testosterone during the critical period for sexual differentiation masculinizes oSDN volume and aromatase expression when examined subsequently on day 135. The demonstration that the oSDN is organized prenatally by testosterone exposure suggests that the brain of the male-oriented ram may be under-androgenized during development. Copyright 2009 Elsevier Ltd. All rights reserved.

Penis size interacts with body shape and height to influence male attractiveness

PubMed Central

Mautz, Brian S.; Wong, Bob B. M.; Peters, Richard A.; Jennions, Michael D.

2013-01-01

Compelling evidence from many animal taxa indicates that male genitalia are often under postcopulatory sexual selection for characteristics that increase a male’s relative fertilization success. There could, however, also be direct precopulatory female mate choice based on male genital traits. Before clothing, the nonretractable human penis would have been conspicuous to potential mates. This observation has generated suggestions that human penis size partly evolved because of female choice. Here we show, based upon female assessment of digitally projected life-size, computer-generated images, that penis size interacts with body shape and height to determine male sexual attractiveness. Positive linear selection was detected for penis size, but the marginal increase in attractiveness eventually declined with greater penis size (i.e., quadratic selection). Penis size had a stronger effect on attractiveness in taller men than in shorter men. There was a similar increase in the positive effect of penis size on attractiveness with a more masculine body shape (i.e., greater shoulder-to-hip ratio). Surprisingly, larger penis size and greater height had almost equivalent positive effects on male attractiveness. Our results support the hypothesis that female mate choice could have driven the evolution of larger penises in humans. More broadly, our results show that precopulatory sexual selection can play a role in the evolution of genital traits. PMID:23569234

Fatal attraction: sexually cannibalistic invaders attract naive native mantids

PubMed Central

Fea, Murray P.; Stanley, Margaret C.; Holwell, Gregory I.

2013-01-01

Overlap in the form of sexual signals such as pheromones raises the possibility of reproductive interference by invasive species on similar, yet naive native species. Here, we test the potential for reproductive interference through heterospecific mate attraction and subsequent predation of males by females of a sexually cannibalistic invasive praying mantis. Miomantis caffra is invasive in New Zealand, where it is widely considered to be displacing the only native mantis species, Orthodera novaezealandiae, and yet mechanisms behind this displacement are unknown. We demonstrate that native males are more attracted to the chemical cues of introduced females than those of conspecific females. Heterospecific pairings also resulted in a high degree of mortality for native males. This provides evidence for a mechanism behind displacement that has until now been undetected and highlights the potential for reproductive interference to greatly influence the impact of an invasive species. PMID:24284560

Gender, Ethnicity, Religiosity, and Same-sex Sexual Attraction and the Acceptance of Same-sex Sexuality and Gender Non-conformity

PubMed Central

Bos, Henny M. W.; Merry, Michael S.; Sandfort, Theo G. M.

2012-01-01

This study explored the role of gender, ethnicity, religiosity, and sexual attraction in adolescents’ acceptance of same-sex sexuality and gender non-conformity. Using an intersectionality perspective, we also tested whether the effects of gender, ethnicity, and religiosity on adolescents’ attitudes would function differently in adolescents with and without same-sex attractions. Data for this study were collected by means of a paper questionnaire completed by 1,518 secondary school students (mean age = 14.56 years, SD = 1.05) in Amsterdam, the Netherlands. The sample was 48.1% female and 51.9% male. Approximately one third of adolescents in the sample were of a non-Western ethnic background (32.3%, n = 491) and 7.5% of the participants (n = 114) reported experiencing same-sex attractions. Results of our analyses showed that adolescents in our sample who were male, of non-Western ethnicity, and who were more religious (as indicated by frequency of religious service attendance), were less accepting of same-sex sexuality and gender non-conformity in comparison to female, Western and less religious peers. We also found a significant interaction effect between religiosity and sexual attractions, but only in relation to evaluation of same-sex attracted, gender nonconforming females. The negative effect of religiosity on acceptance of same-sex attracted, gender non-conforming females was stronger among those adolescents who reported same-sex attractions. PMID:23687403

Gender, Ethnicity, Religiosity, and Same-sex Sexual Attraction and the Acceptance of Same-sex Sexuality and Gender Non-conformity.

PubMed

Collier, Kate L; Bos, Henny M W; Merry, Michael S; Sandfort, Theo G M

2013-06-01

This study explored the role of gender, ethnicity, religiosity, and sexual attraction in adolescents' acceptance of same-sex sexuality and gender non-conformity. Using an intersectionality perspective, we also tested whether the effects of gender, ethnicity, and religiosity on adolescents' attitudes would function differently in adolescents with and without same-sex attractions. Data for this study were collected by means of a paper questionnaire completed by 1,518 secondary school students (mean age = 14.56 years, SD = 1.05) in Amsterdam, the Netherlands. The sample was 48.1% female and 51.9% male. Approximately one third of adolescents in the sample were of a non-Western ethnic background (32.3%, n = 491) and 7.5% of the participants ( n = 114) reported experiencing same-sex attractions. Results of our analyses showed that adolescents in our sample who were male, of non-Western ethnicity, and who were more religious (as indicated by frequency of religious service attendance), were less accepting of same-sex sexuality and gender non-conformity in comparison to female, Western and less religious peers. We also found a significant interaction effect between religiosity and sexual attractions, but only in relation to evaluation of same-sex attracted, gender nonconforming females. The negative effect of religiosity on acceptance of same-sex attracted, gender non-conforming females was stronger among those adolescents who reported same-sex attractions.

Sexual selection on cuticular hydrocarbons in the Australian field cricket, Teleogryllus oceanicus

PubMed Central

Thomas, Melissa L; Simmons, Leigh W

2009-01-01

Background Females in a wide range of taxa have been shown to base their choice of mates on pheromone signals. However, little research has focussed specifically on the form and intensity of selection that mate choice imposes on the pheromone signal. Using multivariate selection analysis, we characterise directly the form and intensity of sexual selection acting on cuticular hydrocarbons, chemical compounds widely used in the selection of mates in insects. Using the Australian field cricket Teleogryllus oceanicus as a model organism, we use three measures of male attractiveness to estimate fitness; mating success, the duration of courtship required to elicit copulation, and subsequent spermatophore attachment duration. Results We found that all three measures of male attractiveness generated sexual selection on male cuticular hydrocarbons, however there were differences in the form and intensity of selection among these three measures. Mating success was the only measure of attractiveness that imposed both univariate linear and quadratic selection on cuticular hydrocarbons. Although we found that all three attractiveness measures generated nonlinear selection, again only mating success was found to exert statistically significant stabilizing selection. Conclusion This study shows that sexual selection plays an important role in the evolution of male cuticular hydrocarbon signals. PMID:19594896

Focal lesions within the ventral striato-pallidum abolish attraction for male chemosignals in female mice.

PubMed

Agustín-Pavón, Carmen; Martínez-García, Fernando; Lanuza, Enrique

2014-02-01

In rodents, socio-sexual behaviour is largely mediated by chemosensory cues, some of which are rewarding stimuli. Female mice display an innate attraction towards male chemosignals, dependent on the vomeronasal system. This behaviour likely reflects the hedonic value of sexual chemosignals. The anteromedial aspect of the olfactory tubercle, along with its associated islands of Calleja, receives vomeronasal inputs and sexually-dimorphic vasopressinergic innervation. Thus, we hypothesised that this portion of the ventral striato-pallidum, known to be involved in reward processing, might be important for sexual odorant-guided behaviours. In this study, we demonstrate that lesions of this region, but not of regions in the posterolateral striato-pallidum, abolish the attraction of female mice for male chemosignals, without affecting significantly their preference for a different natural reward (a sucrose solution). These results show that, at least in female mice, the integrity of the anterior aspect of the medioventral striato-pallidum, comprising a portion of the olfactory tubercle and associated islands of Calleja, is necessary for the attraction for male chemosignals. We suggest that this region contributes to the processing of the hedonic properties of biologically significant odorants. Copyright © 2013 Elsevier B.V. All rights reserved.

Are attractive male crickets better able to pay the costs of an immune challenge?

PubMed Central

Telemeco, Melissa S.C.; Bartholomay, Lyric C.

2015-01-01

Reproduction and immunity are fitness-related traits that trade-off with each other. Parasite-mediated theories of sexual selection suggest, however, that higher-quality males should suffer smaller costs to reproduction-related traits and behaviours (e.g., sexual display) from an immune challenge because these males possess more resources with which to deal with the challenge. We used Gryllus texensis field crickets to test the prediction that attractive males should better maintain the performance of fitness-related traits (e.g., calling effort) in the face of an immune challenge compared with unattractive males. We found no support for our original predictions. However, that immune activation causes attractive males to significantly increase their calling effort compared with unattractive males suggests that these males might terminally invest in order to compensate for decreased future reproduction. PMID:26713249

Automatic Direction of Spatial Attention to Male Versus Female Stimuli: A Comparison of Heterosexual Men and Women.

PubMed

Snowden, Robert J; Curl, Catriona; Jobbins, Katherine; Lavington, Chloe; Gray, Nicola S

2016-05-01

Abundant research has shown that men's sexual attractions are more category-specific in relation to gender than women's are. We tested whether the early automatic allocation of spatial attention reflects these sexual attractions. The dot-probe task was used to assess whether spatial attention was attracted to images of either male or female models that were naked or partially clothed. In Experiment 1, men were faster if the target appeared after the female stimulus, whereas women were equally quick to respond to targets after male or female stimuli. In Experiment 2, neutral cues were introduced. Men were again faster to female images in comparison to male or neutral images, but showed no bias on the male versus neutral test. Women were faster to both male and female pictures in comparison to neutral pictures. However, in this experiment they were also faster to female pictures than to male pictures. The results suggest that early attentional processes reveal category-specific interest to the preferred sexual category for heterosexual men, and suggest that heterosexual women do not have category-specific guidance of attentional mechanisms. The technique may have promise in measuring sexual interest in other situations where participants may not be able, or may not be willing, to report upon their sexual interests (e.g., assessment of paedophilic interest).

A gender- and sexual orientation-dependent spatial attentional effect of invisible images.

PubMed

Jiang, Yi; Costello, Patricia; Fang, Fang; Huang, Miner; He, Sheng

2006-11-07

Human observers are constantly bombarded with a vast amount of information. Selective attention helps us to quickly process what is important while ignoring the irrelevant. In this study, we demonstrate that information that has not entered observers' consciousness, such as interocularly suppressed (invisible) erotic pictures, can direct the distribution of spatial attention. Furthermore, invisible erotic information can either attract or repel observers' spatial attention depending on their gender and sexual orientation. While unaware of the suppressed pictures, heterosexual males' attention was attracted to invisible female nudes, heterosexual females' attention was attracted to invisible male nudes, gay males behaved similarly to heterosexual females, and gay/bisexual females performed in-between heterosexual males and females.

A gender- and sexual orientation-dependent spatial attentional effect of invisible images

PubMed Central

Jiang, Yi; Costello, Patricia; Fang, Fang; Huang, Miner; He, Sheng

2006-01-01

Human observers are constantly bombarded with a vast amount of information. Selective attention helps us to quickly process what is important while ignoring the irrelevant. In this study, we demonstrate that information that has not entered observers' consciousness, such as interocularly suppressed (invisible) erotic pictures, can direct the distribution of spatial attention. Furthermore, invisible erotic information can either attract or repel observers' spatial attention depending on their gender and sexual orientation. While unaware of the suppressed pictures, heterosexual males' attention was attracted to invisible female nudes, heterosexual females' attention was attracted to invisible male nudes, gay males behaved similarly to heterosexual females, and gay/bisexual females performed in-between heterosexual males and females. PMID:17075055

Males of Hylamorpha elegans burmeister (Coleoptera: Scarabaeidae) are attracted to odors released from conspecific females.

PubMed

Quiroz, Andrés; Palma, Ruben; Etcheverría, Paulina; Navarro, Vicente; Rebolledo, Ramón

2007-04-01

The behavioral responses of Hylamorpha elegans L. (Coleoptera: Scarabaeidae, Rutelinae) to the semiochemicals released from conspecific individual adults were studied, with particular attention paid to female attraction of males. Odors released from virgin females significantly attracted male conspecifics in both the field and laboratory olfactometer and wind tunnel bioassays. However, females did not attract other females, and males attracted no one. The response of male H. elegans to (1) compounds (1,4-hydroquinone and 1,4-benzoquinone) released only by unmated females; (2) the essential oil of the secondary host (Nothofagus obliqua); and (3) the blend of 1,4-hydroquinone and 1,4-benzoquinone with N. obliqua essential oil was studied. The blend of 1,4-benzoquinone mixed with essential oil at the trial concentration was attractive with males. The same response was found with 1,4-hydroquinone alone. The essential oil did not have the expected attractant effect on conspecific males. These results suggest that, when combined with essential oil, 1,4-benzoquinone may function in the sexual behavior of males and females. These findings are discussed in terms of the ecological role of this putative sexual pheromone and its potential use in a strategy of control of this pest.

Measuring Implicit Sexual Response Biases to Nude Male and Female Pictures in Androphilic and Gynephilic Men.

PubMed

Timmins, Liam; Barnes-Holmes, Dermot; Cullen, Claire

2016-05-01

Snowden, Wichter, and Gray (2008) demonstrated that an Implicit Association Test and a Priming Task both predicted the sexual orientation of gynephilic and androphilic men in terms of their attraction biases towards pictures of nude males and females. For both measures, relative bias scores were obtained, with no information on the separate response biases to each target gender. The present study sought to extend this research by assessing both relative and individual implicit biases using the Implicit Relational Assessment Procedure (IRAP). An explicit measure screened for men with androphilic (n = 16) or gynephilic (n = 16) orientations on the dimensions of "sexual attraction," "sexual behavior," "sexual fantasies," "hetero/gay lifestyle," and "self identification." The IRAP involved responding "True" or "False" to pictures of nude males and females as either attractive or unattractive. Participants were required to respond in a manner consistent with their reported sexual orientation for half of the IRAP's test blocks and inconsistent for the other half. Response latencies were recorded and analyzed. The IRAP revealed a non-orthogonal pattern of biases across the two groups and had an excellent ability to predict sexual orientation with areas under the curves of 1.0 for the relative bias score and .94 and .95 for the bias scores for the male and female pictures, respectively. Correlations between the IRAP and explicit measures of sexual orientation were consistently high. The findings support the IRAP as a potentially valuable tool in the study of sexual preferences.

Attraction and consumption of methyl eugenol by male Bactrocera umbrosa Fabricius (Diptera: Tephritidae) promotes conspecific sexual communication and mating performance.

PubMed

Wee, S L; Abdul Munir, M Z; Hee, A K W

2018-02-01

The Artocarpus fruit fly, Bactrocera umbrosa (Fabricius) (Diptera: Tephritidae), is an oligophagous fruit pest infesting Moraceae fruits, including jackfruit (Artocarpus heterophyllus Lamarck), a fruit commodity of high value in Malaysia. The scarcity of fundamental biological, physiological and ecological information on this pest, particularly in relation to behavioural response to phytochemical lures, which are instrumental to the success of many area-wide fruit fly control and management programmes, underpins the need for studies on this much-underrated pest. The positive response of B. umbrosa males to methyl eugenol (ME), a highly potent phytochemical lure, which attracts mainly males of many Bactrocera species, was shown to increase with increasing age. As early as 7 days after emergence (DAE), ca. 22% of males had responded to ME and over 50% by 10 DAE, despite no occurrence of matings (i.e. the males were still sexually immature). Male attraction to ME peaked from 10 to 27 DAE, which corresponded with the flies' attainment of sexual maturity. In wind-tunnel assays during the dusk courtship period, ME-fed males exhibited earlier calling activity and attracted a significantly higher percentage of virgin females compared with ME-deprived males. ME-fed males enjoyed a higher mating success than ME-deprived males at 1-day post ME feeding in semi-field assays. ME consumption also promotes aggregation behaviour in B. umbrosa males, as demonstrated in wind-tunnel and semi-field assays. We suggest that ME plays a prominent role in promoting sexual communication and enhancing mating performance of the Artocarpus fruit fly, a finding that is congruent with previous reports on the consequences of ME acquisition by other economically important Bactrocera species.

Effects of Gender, Rape-Supportive Attitudes, and Explicit Instruction on Perceptions of Women’s Momentary Sexual Interest

PubMed Central

Treat, Teresa A.; Church, Erin K.; Viken, Richard J.

2016-01-01

Contemporary models of male-initiated sexual aggression toward female acquaintances implicate misperception of women’s sexual interest. The current study investigated the effects of gender, rape-supportive attitudes, and an instructional manipulation on college students’ sexual-interest judgments. 276 women and 220 men judged the cues of momentary sexual interest expressed by photographed women; half received instruction on the differential validity of nonverbal cues of sexual interest for estimation of women’s momentary sexual interest. Participants also completed an assessment of rape-supportive attitudes. Overall, college students’ perceptions of women’s momentary sexual interest are compromised both nomothetically and idiographically. Both male and female college students relied not only on women’s nonverbal affect but also on the provocativeness of women’s clothing and attractiveness when judging women’s sexual interest. Men and women showed similar average ratings, but women relied more than men on women’s affect, whereas men relied more than women on women’s attractiveness. Both male and female students who endorsed more rape-supportive attitudes, relative to their peers, relied less on women’s affect and more on women’s clothing style and attractiveness. Explicit instruction regarding the greater validity of women’s affective than non-affective cues enhanced focus on non-verbal affective cues and decreased focus on clothing style and attractiveness. Although higher rape-supported attitudes predicted more deficits in processing cues of sexual interest, explicit instruction proved to be effective for both higher-risk and lower-risk participants. These findings highlight the generalizability of the well-established effects of explicit instruction on category learning to sexual perception and may point to procedures that eventually could be incorporated into augmented prevention programs for sexual aggression on college campuses. PMID:27753046

Effects of gender, rape-supportive attitudes, and explicit instruction on perceptions of women's momentary sexual interest.

PubMed

Treat, Teresa A; Church, Erin K; Viken, Richard J

2017-06-01

Contemporary models of male-initiated sexual aggression toward female acquaintances implicate misperception of women's sexual interest. This study investigated the effects of gender, rape-supportive attitudes and an instructional manipulation on college students' sexual-interest judgments. Two hundred seventy-six women and 220 men judged the cues of momentary sexual interest expressed by photographed women; half received instruction on the differential validity of nonverbal cues of sexual interest for estimation of women's momentary sexual interest. Participants also completed an assessment of rape-supportive attitudes. Overall, college students' perceptions of women's momentary sexual interest are compromised both nomothetically and idiographically. Both male and female college students relied not only on women's nonverbal affect but also on the provocativeness of women's clothing and attractiveness when judging women's sexual interest. Men and women showed similar average ratings, but women relied more than men on women's affect, whereas men relied more than women on women's attractiveness. Both male and female students who endorsed more rape-supportive attitudes, relative to their peers, relied less on women's affect and more on women's clothing style and attractiveness. Explicit instruction regarding the greater validity of women's affective than nonaffective cues enhanced focus on nonverbal affective cues and decreased focus on clothing style and attractiveness. Although higher rape-supportive attitudes predicted more deficits in processing cues of sexual interest, explicit instruction proved to be effective for both higher-risk and lower-risk participants. These findings highlight the generalizability of the well-established effects of explicit instruction on category learning to sexual perception and may point to procedures that eventually could be incorporated into augmented prevention programs for sexual aggression on college campuses.

Refining the dual olfactory hypothesis: pheromone reward and odour experience.

PubMed

Martínez-García, Fernando; Martínez-Ricós, Joana; Agustín-Pavón, Carmen; Martínez-Hernández, Jose; Novejarque, Amparo; Lanuza, Enrique

2009-06-25

In rodents, sexual advertisement and gender recognition are mostly (if not exclusively) mediated by chemosignals. Specifically, there is ample evidence indicating that female mice are 'innately' attracted by male sexual pheromones that have critical non-volatile components and are detected by the vomeronasal organ. These pheromones can only get access to the vomeronasal organ by active pumping mechanisms that require close contact with the source of the stimulus (e.g. urine marks) during chemoinvestigation. We have hypothesised that male sexual pheromones are rewarding to female mice. Indeed, male-soiled bedding can be used as a reinforcer to induce conditioned place preference, provided contact with the bedding is allowed. The neural mechanisms of pheromone reward seem, however, different from those employed by other natural reinforcers, such as the sweetness or postingestive effects of sucrose. In contrast to vomeronasal-detected male sexual pheromones, male-derived olfactory stimuli (volatiles) are not intrinsically attractive to female mice. However, after repeated exposure to male-soiled bedding, intact female mice develop an acquired preference for male odours. On the contrary, in females whose accessory olfactory bulbs have been lesioned, exposure to male-soiled bedding induces aversion to male odorants. These considerations, together with data on the different properties of olfactory and vomeronasal receptors, lead us to make a proposal for the complementary roles that the olfactory and vomeronasal systems play in intersexual attraction and in other forms of intra- or inter-species communication.

Stability of Self-Reported Same-Sex and Both-Sex Attraction from Adolescence to Young Adulthood.

PubMed

Hu, Yueqin; Xu, Yishan; Tornello, Samantha L

2016-04-01

This study examined how sexual attraction varied across age, gender of participant, and gender of romantic partner, from adolescence to early adulthood. Comparisons between same-sex and both-sex attracted individuals were of particular interest. Using the National Longitudinal Study of Adolescent Health (AddHealth), we examined the responses of participants who reported experiencing same-sex attractions or both-sex attractions at least once within four waves (n = 1889). Results indicated that same-sex attractions became more stable over time, whereas both-sex attraction remained unstable even into adulthood. Compared with males, females were less stable in same-sex attraction, but more stable in both-sex attraction. The majority of people who reported same-sex attraction did not report having a same-sex romantic partner before they entered adulthood, and those who reported a same-sex romantic partner were more likely to maintain their same-sex attraction than those who did not. As males got older, the gender of their romantic partner tended to become more consistent with their sexual attraction. However, for females, the consistency between the gender of their romantic partner and sexual attraction did not change over time.

Sexual behavior, sexual attraction, and sexual identity in the United States: data from the 2006-2008 National Survey of Family Growth.

PubMed

Chandra, Anjani; Mosher, William D; Copen, Casey; Sionean, Catlainn

2011-03-03

This report presents national estimates of several measures of sexual behavior, sexual attraction, and sexual identity among males and females aged 15-44 years in the United States, based on the 2006-2008 National Survey of Family Growth (NSFG). These data are relevant to demographic and public health concerns, including fertility and sexually transmitted infections among teenagers and adults. Data from the 2006-2008 NSFG are compared with data from the 2002 NSFG and other national surveys. Data for 2006-2008 were collected through in-person interviews with a national sample of 13,495 males and females in the household population of the United States. The measures presented in this report were collected using audio computer-assisted self interviewing (ACASI), in which the respondent enters his or her own answers into the computer without telling them to an interviewer. The overall response rate for the 2006-2008 NSFG was 75%. Sexual behaviors among males and females aged 15-44 based on the 2006-2008 NSFG were generally similar to those reported based on the 2002 NSFG. Among adults aged 25-44, about 98% of women and 97% of men ever had vaginal intercourse, 89% of women and 90% of men ever had oral sex with an opposite-sex partner, and 36% of women and 44% of men ever had anal sex with an opposite-sex partner. Twice as many women aged 25-44 (12%) reported any same-sex contact in their lifetimes compared with men (5.8%). Among teenagers aged 15-19, 7% of females and 9% of males have had oral sex with an opposite-sex partner, but no vaginal intercourse. Sexual attraction and identity correlates closely but not completely with reports of sexual behavior. Sexual behaviors, attraction, and identity vary by age, marital or cohabiting status, education, and race and Hispanic origin.

Seminal Fluid Regulation of Female Sexual Attractiveness in Drosophila melanogaster

NASA Astrophysics Data System (ADS)

Tram, Uyen; Wolfner, Mariana F.

1998-03-01

Finding a willing and suitable mate is critical for sexual reproduction. Visual, auditory, and chemical cues aid in locating and/or attracting partners. After mating, females from many insect species become less attractive. This is caused by changes in the quantity and/or quality of pheromones synthesized by the female and to changes in the female's behavior. For example, female insects may stop releasing pheromones, assume a mate refusal posture, or move less in response to males. Many postmating changes in female insects are triggered by seminal fluid proteins from the male's accessory gland proteins (Acps) and by sperm. To determine the role of seminal fluid components in mediating changes in attractiveness, we measured the attractiveness of Drosophila melanogaster females that had been mated to genetically altered males that lack sperm and/or Acps. We found that the drop in female attractiveness occurs in two phases. A short-term drop in attractiveness is triggered independent of the receipt of sperm and Acps. Maintenance of lowered attractiveness is dependent upon sperm.

The sexual selection paradigm: have we overlooked other mechanisms in the evolution of male ornaments?

PubMed

Candolin, Ulrika; Tukiainen, Iina

2015-10-07

Extravagant male ornaments expressed during reproduction are almost invariably assumed to be sexually selected and evolve through competition for mating opportunities. Yet in species where male reproductive success depends on the defence of offspring, male ornaments could also evolve through social competition for offspring survival. However, in contrast to female ornaments, this possibility has received little attention in males. We show that a male ornament that is traditionally assumed to be sexually selected--the red nuptial coloration of the three-spined stickleback--is under stronger selection for offspring survival than for mating success. Males express most coloration during parenting, when they no longer attract females, and the colour correlates with nest retention and hatching success but not with attractiveness to females. This contradicts earlier assumptions and suggests that social selection for offspring survival rather than for sexual selection for mating success is the main mechanism maintaining the ornament in the population. These results suggest that we should consider other forms of social selection beyond sexual selection when seeking to explain the function and evolution of male ornaments. An incorrect assignment of selection pressures could hamper our understanding of evolution. © 2015 The Author(s).

Sexual selection on male vocal fundamental frequency in humans and other anthropoids.

PubMed

Puts, David A; Hill, Alexander K; Bailey, Drew H; Walker, Robert S; Rendall, Drew; Wheatley, John R; Welling, Lisa L M; Dawood, Khytam; Cárdenas, Rodrigo; Burriss, Robert P; Jablonski, Nina G; Shriver, Mark D; Weiss, Daniel; Lameira, Adriano R; Apicella, Coren L; Owren, Michael J; Barelli, Claudia; Glenn, Mary E; Ramos-Fernandez, Gabriel

2016-04-27

In many primates, including humans, the vocalizations of males and females differ dramatically, with male vocalizations and vocal anatomy often seeming to exaggerate apparent body size. These traits may be favoured by sexual selection because low-frequency male vocalizations intimidate rivals and/or attract females, but this hypothesis has not been systematically tested across primates, nor is it clear why competitors and potential mates should attend to vocalization frequencies. Here we show across anthropoids that sexual dimorphism in fundamental frequency (F0) increased during evolutionary transitions towards polygyny, and decreased during transitions towards monogamy. Surprisingly, humans exhibit greater F0 sexual dimorphism than any other ape. We also show that low-F0 vocalizations predict perceptions of men's dominance and attractiveness, and predict hormone profiles (low cortisol and high testosterone) related to immune function. These results suggest that low male F0 signals condition to competitors and mates, and evolved in male anthropoids in response to the intensity of mating competition. © 2016 The Author(s).

The strength of sexual arousal as a function of the age of the sex offender: comparisons among pedophiles, hebephiles, and teleiophiles.

PubMed

Blanchard, Ray; Barbaree, Howard E

2005-10-01

Previous research has shown that sexual arousability in human males declines from its peak in early adolescence until old age. This study compared the rates of decline in three groups of males: those most attracted sexually to prepubescent children (pedophiles), those most attracted to pubescent children (hebephiles), and those most attracted to physically mature persons (teleiophiles). The participants were 2,028 patients referred to Toronto's Centre for Addiction and Mental Health from 1995 to 2004 for evaluation of criminal or otherwise disturbing sexual behavior, but not for erectile or ejaculatory problems. All underwent phallometric assessment for erotic age-preference. This is a psychophysiological technique in which an individual's penile blood volume is monitored while he is presented with a standardized set of laboratory stimuli depicting male and female children, pubescents, and adults. The experimental measure of sexual arousability was the average of the participant's three greatest penile responses to any stimulus category, expressed in cubic cm of blood volume increase. The results showed that sexual arousability was an inverse function of age, and that there were no differences between the pedophiles, hebephiles, and teleiophiles in the rate at which arousability declined.

Sex-ratio control erodes sexual selection, revealing evolutionary feedback from adaptive plasticity.

PubMed

Fawcett, Tim W; Kuijper, Bram; Weissing, Franz J; Pen, Ido

2011-09-20

Female choice is a powerful selective force, driving the elaboration of conspicuous male ornaments. This process of sexual selection has profound implications for many life-history decisions, including sex allocation. For example, females with attractive partners should produce more sons, because these sons will inherit their father's attractiveness and enjoy high mating success, thereby yielding greater fitness returns than daughters. However, previous research has overlooked the fact that there is a reciprocal feedback from life-history strategies to sexual selection. Here, using a simple mathematical model, we show that if mothers adaptively control offspring sex in relation to their partner's attractiveness, sexual selection is weakened and male ornamentation declines. This weakening occurs because the ability to determine offspring sex reduces the fitness difference between females with attractive and unattractive partners. We use individual-based, evolutionary simulations to show that this result holds under more biologically realistic conditions. Sexual selection and sex allocation thus interact in a dynamic fashion: The evolution of conspicuous male ornaments favors sex-ratio adjustment, but this conditional strategy then undermines the very same process that generated it, eroding sexual selection. We predict that, all else being equal, the most elaborate sexual displays should be seen in species with little or no control over offspring sex. The feedback process we have described points to a more general evolutionary principle, in which a conditional strategy weakens directional selection on another trait by reducing fitness differences.

Self-perceived attractiveness influences human female preferences for sexual dimorphism and symmetry in male faces.

PubMed Central

Little, A C; Burt, D M; Penton-Voak, I S; Perrett, D I

2001-01-01

Exaggerated sexual dimorphism and symmetry in human faces have both been linked to potential 'good-gene' benefits and have also been found to influence the attractiveness of male faces. The current study explores how female self-rated attractiveness influences male face preference in females using faces manipulated with computer graphics. The study demonstrates that there is a relatively increased preference for masculinity and an increased preference for symmetry for women who regard themselves as attractive. This finding may reflect a condition-dependent mating strategy analogous to behaviours found in other species. The absence of a preference for proposed markers of good genes may be adaptive in women of low mate value to avoid the costs of decreased parental investment from the owners of such characteristics. PMID:12123296

Energetic cost of sexual attractiveness: ultrasonic advertisement in wax moths.

PubMed

Reinhold; Greenfield; Jang; Broce

1998-04-01

Pair formation in the lesser wax moth, Achroia grisella (Lepidoptera: Pyralidae), is initiated by male ultrasonic signals that attract receptive females. Individual males vary in attractiveness to females, and the most attractive males are distinguished by exaggeration of three signal characters: pulse rate, peak amplitude and asynchrony interval (temporal separation between pulses generated by movements of the left and right wings during a given wing upstroke or downstroke). Using flow-through respirometry, we measured the resting and signalling metabolic rates of males whose relative attractiveness was known. Acoustic recordings and metabolic measurements were made simultaneously, and we calculated net metabolic rates and factorial metabolic scopes as measures for the energetic cost of signalling. On average, attractive males had higher net metabolic rates and factorial metabolic scopes than unattractive ones, but many unattractive males also had high values. Thus, high expenditure of energy on signalling is necessary but not sufficient for attractiveness. This may result because only one of the three signal characters critical for female preference, pulse rate, is correlated with energy expenditure. Although the results are consistent with the good genes model of sexual selection, they do not conflict with other indirect or direct mechanisms of female choice. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.

Measures of clinical health among female-to-male transgender persons as a function of sexual orientation.

PubMed

Meier, S Colton; Pardo, Seth T; Labuski, Christine; Babcock, Julia

2013-04-01

The present study examined the sexual orientation classification system that was used in the DSM-IV-TR for categorizing those who met the Gender Identity Disorder diagnostic criteria in order to determine the extent to which female-to-male transgender persons (FTMs) differ on psychological variables as a function of sexual orientation. Participants were 605 self-identified FTMs from 19 different countries (83 % U.S.) who completed an internet survey assessing their sexual orientation, sexual identity, symptoms of depression and anxiety, stress (Depression Anxiety Stress Scales), social support (Multidimensional Scale of Perceived Social Support), and health related quality of life (SF-36v2 Health Survey). Over half the sample (52 %) reported sexual attractions to both men and women. The most common sexual identity label reported was "queer." Forty percent of FTMs who had begun to transition reported a shift in sexual orientation; this shift was associated with testosterone use. Overall, FTMs ranged from normal to above average on all psychological measures. FTMs did not significantly differ by sexual attraction on any mental health variables, except for anxiety. FTMs attracted to both men and women reported more symptoms of anxiety than those attracted to men only. Results from the present study did not support a sexual orientation classification system in FTMs with regard to psychological well-being.

The Relationship Between Digit Ratio (2D:4D) and Sexual Orientation in Men from China.

PubMed

Xu, Yin; Zheng, Yong

2016-04-01

We examined the relationship between 2D:4D digit ratio and sexual orientation in men from China and analyzed the influences of the components used to assess sexual orientation and the criteria used to classify individuals as homosexual on this relationship. A total of 309 male and 110 female participants took part in a web-based survey. Our results showed that heterosexual men had a significantly lower 2D:4D than heterosexual women and exclusively homosexual men had a significantly higher left 2D:4D than heterosexual men whereas only exclusively homosexual men had a significantly higher right 2D:4D than heterosexual men when sexual orientation was assessed via sexual attraction. The left 2D:4D showed a significant positive correlation with sexual identity, sexual attraction, and sexual behavior, and the right 2D:4D showed a significant positive correlation with sexual attraction. The effect sizes for differences in 2D:4D between homosexual and heterosexual men varied according to criteria used to classify individuals as homosexual and sexual orientation components; the more stringent the criteria (scores closer to the homosexual category), the larger the effect sizes; further, sexual attraction yielded the largest effect size. There were no significant effects of age and latitude on Chinese 2D:4D. This study contributes to the current understanding of the relationship between 2D:4D and male sexual orientation.

Red is not a proxy signal for female genitalia in humans.

PubMed

Johns, Sarah E; Hargrave, Lucy A; Newton-Fisher, Nicholas E

2012-01-01

Red is a colour that induces physiological and psychological effects in humans, affecting competitive and sporting success, signalling and enhancing male social dominance. The colour is also associated with increased sexual attractiveness, such that women associated with red objects or contexts are regarded as more desirable. It has been proposed that human males have a biological predisposition towards the colour red such that it is 'sexually salient'. This hypothesis argues that women use the colour red to announce impending ovulation and sexual proceptivity, with this functioning as a proxy signal for genital colour, and that men show increased attraction in consequence. In the first test of this hypothesis, we show that contrary to the hypothesis, heterosexual men did not prefer redder female genitalia and, by extension, that red is not a proxy signal for genital colour. We found a relative preference for pinker genital images with redder genitalia rated significantly less sexually attractive. This effect was independent of raters' prior sexual experience and variation in female genital morphology. Our results refute the hypothesis that men's attraction to red is linked to an implied relationship to genital colour and women's signalling of fertility and sexual proceptivity.

The responsiveness of Bactrocera jarvisi (Diptera: Tephritidae) to two naturally occurring phenylbutaonids, zingerone and raspberry ketone.

PubMed

Wee, Suk-Ling; Peek, Thelma; Clarke, Anthony R

2018-06-08

The males of different species of Bactrocera and Zeugodacus fruit flies are commonly attracted to plant-derived phenylpropanoids (e.g. methyl eugenol (ME)) or phenylbutanoids (e.g. raspberry ketone (RK)) but almost never to both. However, one particular plant-derived phenylbutanoid, zingerone (ZN), which possesses an intermediate chemical structure between ME and RK, weakly attracts both ME- and RK-responding fruit fly species. Bactrocera jarvisi, an Australian fruit fly species, is weakly attracted to cue lure (an analogue of RK) but strongly attracted to ZN. Here, we investigated the minimum olfactory threshold and optimum sensitivity of B. jarvisi males to ZN and RK as a function of dose, time and sexual maturation. Our results show that B. jarvisi males had a marked preferential response to ZN, with a much lower olfactory threshold and faster response time to ZN than RK. Probit analysis demonstrated that ZN was at least >1600× more potent than RK as a male attractant to B. jarvisi. Although fruit fly male attraction to the phytochemicals is generally associated with sexual maturity, in B. jarvisi immature males were also attracted to ZN. Our results suggest that B. jarvisi males have a fine-tuned olfactory response to ZN, which appears to play a central role in the chemical ecology of this species. Copyright © 2018 Elsevier Ltd. All rights reserved.

Studies of human physique and sexual attractiveness: sexual preferences of men and women in China.

PubMed

Dixson, Barnaby J; Dixson, Alan F; Li, Baoguo; Anderson, M J

2007-01-01

Men and women at Northwest University (n = 631), Xi'an, China, were asked to rate the attractiveness of male or female figures manipulated to vary somatotype, waist-to-hip ratio (WHR), secondary sexual traits, and other features. In study 1, women rated the average masculine somatotype as most attractive, followed by the mesomorphic (muscular), ectomorphic (slim), and endomorphic (heavily built) somatotypes, in descending order of preference. In study 2, the amount and distribution of masculine trunk (chest and abdominal) hair were altered progressively in a series of front-posed figures. Women rated figures with no or little trunk hair as most attractive. Study 3 assessed the attractiveness of front-posed male figures which varied only in length of their nonerect penis. Numerical ratings for this trait were low, but moderate lengthening of the penis (22% or 33% above average) resulted in a significant increase in scores for attractiveness. In study 4, Chinese men rated the attractiveness of back-posed female images varying in waist-to-hip ratio (WHR from 0.5-1.0). The 0.6 WHR figure was most preferred, followed by 0.7, while figures with higher ratios (0.9 or 1.0) were significantly less attractive. Study 5 rated the attractiveness of female skin color: men expressed a marked preference for images which were lighter in color, as compared to images of average or darker skin colors. These results, the first of their kind reported for a Chinese population, support the view that sexual selection has influenced the evolution of human physique and sexual attractiveness in men and women.

Prenatal Exposure to Progesterone Affects Sexual Orientation in Humans.

PubMed

Reinisch, June M; Mortensen, Erik Lykke; Sanders, Stephanie A

2017-07-01

Prenatal sex hormone levels affect physical and behavioral sexual differentiation in animals and humans. Although prenatal hormones are theorized to influence sexual orientation in humans, evidence is sparse. Sexual orientation variables for 34 prenatally progesterone-exposed subjects (17 males and 17 females) were compared to matched controls (M age = 23.2 years). A case-control double-blind design was used drawing on existing data from the US/Denmark Prenatal Development Project. Index cases were exposed to lutocyclin (bioidentical progesterone = C 21 H 30 O 2 ; M W : 314.46) and no other hormonal preparation. Controls were matched on 14 physical, medical, and socioeconomic variables. A structured interview conducted by a psychologist and self-administered questionnaires were used to collect data on sexual orientation, self-identification, attraction to the same and other sex, and history of sexual behavior with each sex. Compared to the unexposed, fewer exposed males and females identified as heterosexual and more of them reported histories of same-sex sexual behavior, attraction to the same or both sexes, and scored higher on attraction to males. Measures of heterosexual behavior and scores on attraction to females did not differ significantly by exposure. We conclude that, regardless of sex, exposure appeared to be associated with higher rates of bisexuality. Prenatal progesterone may be an underappreciated epigenetic factor in human sexual and psychosexual development and, in light of the current prevalence of progesterone treatment during pregnancy for a variety of pregnancy complications, warrants further investigation. These data on the effects of prenatal exposure to exogenous progesterone also suggest a potential role for natural early perturbations in progesterone levels in the development of sexual orientation.

Cosmetics alter biologically-based factors of beauty: evidence from facial contrast.

PubMed

Jones, Alex L; Russell, Richard; Ward, Robert

2015-02-28

The use of cosmetics by women seems to consistently increase their attractiveness. What factors of attractiveness do cosmetics alter to achieve this? Facial contrast is a known cue to sexual dimorphism and youth, and cosmetics exaggerate sexual dimorphisms in facial contrast. Here, we demonstrate that the luminance contrast pattern of the eyes and eyebrows is consistently sexually dimorphic across a large sample of faces, with females possessing lower brow contrasts than males, and greater eye contrast than males. Red-green and yellow-blue color contrasts were not found to differ consistently between the sexes. We also show that women use cosmetics not only to exaggerate sexual dimorphisms of brow and eye contrasts, but also to increase contrasts that decline with age. These findings refine the notion of facial contrast, and demonstrate how cosmetics can increase attractiveness by manipulating factors of beauty associated with facial contrast.

Pheromones: isolation of male sex attractants from a female primate.

PubMed

Michael, R P; Keverne, E B; Bonsall, R W

1971-05-28

Fractionation of vaginal secretions from rhesus monkeys by partitioning and chromatographic procedures, combined with behavioral studies, demonstrates that short-chain aliphatic acids are responsible for stimulating the sexual behavior of males. Injection of estradiol into ovariectomized females increases the concentration of volatile acids in secretions which will then sexually stimulate these male primates.

The Relationships Between Skin Color and Self-Perceived Global, Physical, and Sexual Attractiveness, and Self-Esteem for African Americans.

ERIC Educational Resources Information Center

Wade, T. Joel

1996-01-01

Examined skin color in relation to self-esteem and self-perceived physical, sexual, and global attractiveness in 91 African Americans. Findings support the hypothesis that fair-skinned females have higher self-esteem and self-ratings of attractiveness than dark-skinned females, and that dark-skinned males have higher or no different ratings from…

The Temporal Stability of Lack of Sexual Attraction Across Young Adulthood.

PubMed

Cranney, Stephen

2016-04-01

There is a large and growing literature on the stability of sexual orientation across the lifespan. However, virtually no studies have been conducted on the longitudinal stability of any dimension of asexuality. Here I utilized Kinsey scale-type data from Wave III and Wave IV of the Add Health survey to measure the stability of indicating "not sexually attracted to either males or females" in a forced-choice, Kinsey-type scale and during the time participants were moving through early adulthood (18-26 years in Wave III and 24-32 years in Wave IV). I found that, for the most part, individuals who reported no sexual attraction in Wave III were not the same individuals who reported no sexual attraction in Wave IV, with only three out of the 25 in Wave III who indicated no sexual attraction going on to do the same in Wave IV. This inter-wave consistency was lower than it was for other sexual minorities. However, indicating no sexual attraction in one wave was still a statistically significant predictor of indicating no sexual attraction in the other wave, as was refusing to answer or indicating the "don't know" option in the other wave. These findings do not necessarily denote change in sexual attraction across waves; the fact that not answering the question in one wave was a significant predictor of indicating no sexual attraction in the other wave provides quantitative evidence for the ambiguities involved in sexual identities when sexuality is taken for granted in the broader culture. This ambiguity affects the operationalization and quantification of asexuality.

The Temporal Stability of Lack of Sexual Attraction across Young Adulthood

PubMed Central

Cranney, Stephen

2017-01-01

There is a large and growing literature on the stability of sexual orientation across the lifespan. However, virtually no studies have been conducted on the longitudinal stability of any dimension of asexuality. Here, I utilized Kinsey scale-type data from Wave III and Wave IV of the Add Health survey to measure the stability of indicating “not sexually attracted to either males or females” in a forced-choice, Kinsey-type scale during the time participants were moving through early adulthood (18-26 in Wave III and 24-32 in Wave IV). I found that, for the most part, individuals who reported no sexual attraction in Wave III were not the same individuals who reported no sexual attraction in Wave IV, with only three out of the 25 in Wave III who indicated no sexual attraction going on to do the same in Wave IV. This inter-wave consistency was lower than it was for other sexual minorities. However, indicating no sexual attraction in one wave was still a statistically significant predictor of indicating no sexual attraction in the other wave, as was refusing to answer or indicating the “don’t know” option in the other wave. These findings do not necessarily denote change in sexual attraction across waves; the fact that not answering the question in one wave was a significant predictor of indicating no sexual attraction in the other wave provides quantitative evidence for the ambiguities involved in sexual identities when sexuality is taken for granted in the broader culture. This ambiguity affects the operationalization and quantification of asexuality. PMID:26228992

Male facial attractiveness and masculinity may provide sex- and culture-independent cues to semen quality.

PubMed

Soler, C; Kekäläinen, J; Núñez, M; Sancho, M; Álvarez, J G; Núñez, J; Yaber, I; Gutiérrez, R

2014-09-01

Phenotype-linked fertility hypothesis (PLFH) predicts that male secondary sexual traits reveal honest information about male fertilization ability. However, PLFH has rarely been studied in humans. The aim of the present study was to test PLFH in humans and to investigate whether potential ability to select fertile partners is independent of sex or cultural background. We found that on the contrary to the hypothesis, facial masculinity was negatively associated with semen quality. As increased levels of testosterone have been demonstrated to impair sperm production, this finding may indicate a trade-off between investments in secondary sexual signalling (i.e. facial masculinity) and fertility or status-dependent differences in investments in semen quality. In both sexes and nationalities (Spanish and Colombian), ranked male facial attractiveness predicted male semen quality. However, Spanish males and females estimated facial images generally more attractive (gave higher ranks) than Colombian raters, and in both nationalities, males gave higher ranks than females. This suggests that male facial cues may provide culture- and sex-independent information about male fertility. However, our results also indicate that humans may be more sensitive to facial attractiveness cues within their own populations and also that males may generally overestimate the attractiveness of other men to females. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

The attractiveness fragment—AFLP analysis of local adaptation and sexual selection in a caeliferan grasshopper, Chorthippus biguttulus

NASA Astrophysics Data System (ADS)

Klappert, Kirsten; Butlin, Roger K.; Reinhold, Klaus

2007-08-01

Genetic variability among males is a necessary precondition for the evolution of female choice based on indirect genetic benefits. In addition to mutations and host parasite cycles, migration of locally adapted individuals offers an explanation for the maintenance of genetic variability. In a previous study, conducting a reciprocal transplant experiment on a grasshopper, Chorthippus biguttulus, we found that environmental conditions significantly influenced not only body condition but also an important trait of male calling song, the amplitude of song. Although not significant, all other analysed physical and courtship song traits and attractiveness were superior in native than in transferred males. Thus, we concluded that local adaptation has a slight but consistent influence on a range of traits in our study populations, including male acoustic attractiveness. In our present study, we scanned male grasshoppers from the same two populations for amplification fragment length polymorphism (AFLP) loci connected with acoustic attractiveness to conspecific females. We found greater differences in allele frequencies between the two populations, for some loci, than are expected from a balance between drift and gene flow. These loci are potentially connected with locally adapted traits. We examined whether these alleles show the proposed genotype environment interaction by having different associations with attractiveness in the two populations. One locus was significantly related to sexual attractiveness; however, this was independent of the males’ population affiliation. Future research on the evolution of female choice will benefit from knowledge of the underlying genetic architecture of male traits under intraspecific sexual selection, and the ‘population genomics’ approach can be a powerful tool for revealing this structure.

From sexual attraction to maternal aggression: when pheromones change their behavioural significance.

PubMed

Martín-Sánchez, Ana; McLean, Lynn; Beynon, Robert J; Hurst, Jane L; Ayala, Guillermo; Lanuza, Enrique; Martínez-Garcia, Fernando

2015-02-01

This article is part of a Special Issue "Chemosignals and Reproduction". This paper reviews the role of chemosignals in the socio-sexual interactions of female mice, and reports two experiments testing the role of pup-derived chemosignals and the male sexual pheromone darcin in inducing and promoting maternal aggression. Female mice are attracted to urine-borne male pheromones. Volatile and non-volatile urine fractions have been proposed to contain olfactory and vomeronasal pheromones. In particular, the male-specific major urinary protein (MUP) MUP20, darcin, has been shown to be rewarding and attractive to females. Non-urinary male chemosignals, such as the lacrimal protein ESP1, promote lordosis in female mice, but its attractive properties are still to be tested. There is evidence indicating that ESP1 and MUPs are detected by vomeronasal type 2 receptors (V2R). When a female mouse becomes pregnant, she undergoes dramatic changes in her physiology and behaviour. She builds a nest for her pups and takes care of them. Dams also defend the nest against conspecific intruders, attacking especially gonadally intact males. Maternal behaviour is dependent on a functional olfactory system, thus suggesting a role of chemosignals in the development of maternal behaviour. Our first experiment demonstrates, however, that pup chemosignals are not sufficient to induce maternal aggression in virgin females. In addition, it is known that vomeronasal stimuli are needed for maternal aggression. Since MUPs (and other molecules) are able to promote intermale aggression, in our second experiment we test if the attractive MUP darcin also promotes attacks on castrated male intruders by lactating dams. Our findings demonstrate that the same chemosignal, darcin, promotes attraction or aggression according to female reproductive state. Copyright © 2014 Elsevier Inc. All rights reserved.

The Role of Facial and Body Hair Distribution in Women's Judgments of Men's Sexual Attractiveness.

PubMed

Dixson, Barnaby J W; Rantala, Markus J

2016-05-01

Facial and body hair are some of the most visually conspicuous and sexually dimorphic of all men's secondary sexual traits. Both are androgen dependent, requiring the conversion of testosterone into dihydrotestosterone via the enzyme 5α reductase 2 for their expression. While previous studies on the attractiveness of facial and body hair are equivocal, none have accounted as to how natural variation in their distribution may influence male sexual attractiveness. In the present study, we quantified men's facial and body hair distribution as either very light, light, medium, or heavy using natural photographs. We also tested whether women's fertility influenced their preferences for beards and body hair by comparing preferences among heterosexual women grouped according their fertility (high fertility, low fertility, and contraceptive use). Results showed that men with more evenly and continuously distributed facial hair from the lower jaw connecting to the mustache and covering the cheeks were judged as more sexually attractive than individuals with more patchy facial hair. Men with body hair were less attractive than when clean shaven, with the exception of images depicting some hair around the areolae, pectoral region, and the sternum that were significantly more attractive than clean-shaven bodies. However, there was no effect of fertility on women's preferences for men's beard or body hair distribution. These results suggest that the distribution of facial and body hair influences male attractiveness to women, possibly as an indication of masculine development and the synthesis of testosterone into dihydrotestosterone via 5α reductase.

Subjective Sexual Experiences of Behaviorally Bisexual Men in the Midwestern United States: Sexual Attraction, Sexual Behaviors, & Condom Use

PubMed Central

Schnarrs, Phillip W.; Dodge, Brian; Reece, Michael; Goncalves, Gabriel; Martinez, Omar; Van Der Pol, Barbara; Malebranche, David; Murray, Maresa; Nix, Ryan; Fortenberry, J. Dennis

2012-01-01

Studies concerning behaviorally bisexual men continue to focus on understanding sexual risk in according to a narrow range of sexual behaviors. Few studies have explored the subjective meanings and experiences related to bisexual men’s sexual behaviors with both male and female partners. In-depth, semi-structured interviews were conducted with 75 men who engaged in bisexual behavior within the past six months. Participants were asked about their subjective sexual experiences with male and female partners. Findings suggest adherence to normative gender roles, with attraction to men and women conforming to these stereotypes, as well as a segregation of sexual behaviors along gendered lines. Overall, condom use was influenced by perceptions of potential negative consequences. Based on these findings, it remains critical that public health and other social and behavioral sciences continue to study bisexual men’s sexual health issues as separate and distinct from their exclusively homosexual and heterosexual counterparts. PMID:22745592

Sexual assault as a crime against young people.

PubMed

Felson, Richard B; Cundiff, Patrick R

2014-02-01

Evidence based on almost 300,000 sexual assaults from the National Incident-Based Reporting System showed that the modal age of victims was 15 years, regardless of the age of the offender, the gender of the offender, or the gender of the victim. We suggest that adolescents have the highest risk of victimization because of their sexual attractiveness, vulnerability, and exposure to motivated offenders. As a result of these factors, sexual assault is as much an offense against young people as it is against women. The sexual attractiveness of young people also has implications for the age of offenders. Older men have much higher rates of offending than one would expect, given the age-desistance relationship. Thus, we found that older men have much higher rates of sexual assault than physical assault. Finally, evidence suggested that homosexual men were at least as likely as heterosexual men to commit sexual assault. The pattern suggests that the tendency for sexual assaults to involve male offenders and female victims reflects male sexuality rather than attitudes toward women.

Coloured leg bands affect male mate-guarding behaviour in the bluethroat

PubMed

Johnsen; Lifjeld; Rohde

1997-07-01

Artificial traits such as coloured leg bands may affect an individual's mating success, as shown for some birds. One explanation is that colour-matching with a sexual ornament affects the individual's sexual attractiveness. This study reports a colour-band experiment with free-living bluethroats, Luscinia s. svecicaa species where males have a distinct blue and chestnut throat and upper breast. There was no apparent difference in pairing success between males with ornament-matching colour bands (blue and orange) and males with non-ornamental colour bands. However, males with ornamental bands guarded their mates less intensely and spent more time singing, performing song flights and intruding into neighbours' territories than males with non-ornamental bands. We conclude that colour bands affect the trade-off between mate guarding and advertisement behaviour in a way that is consistent with the hypothesis that bands with ornamental colours improve a male's attractiveness. The results are in concordance with a previous study of the same population, showing that males with experimentally reduced attractiveness guarded their mates more closely and advertised less for additional mates, than non-manipulated males.

Sexual harassment victimization and perpetration among high school students.

PubMed

Clear, Emily R; Coker, Ann L; Cook-Craig, Patricia G; Bush, Heather M; Garcia, Lisandra S; Williams, Corrine M; Lewis, Alysha M; Fisher, Bonnie S

2014-10-01

This large, population-based study is one of the few to examine prevalence rates of sexual harassment occurring during the past 12 months by victimization and perpetration among adolescents. In this large, cross-sectional survey of students attending 26 high schools, sexual harassment was defined using three questions from the Sexual Experiences Questionnaire. Among 18,090 students completing the survey, 30% disclosed sexual harassment victimization (37% of females, 21% of males) and 8.5% reported perpetration (5% of females, 12% of males). Sexual harassment perpetration was highly correlated with male sex, minority race/ethnicity, same-sex attraction, bullying, alcohol binge drinking, and intraparental partner violence. © The Author(s) 2014.

Male Readership Differences in Liquor Magazine Ads Employing Nonsensical and Sexual Humor.

ERIC Educational Resources Information Center

Reid, Leonard N.; And Others

A study examined the attention getting value of nonsensical and sexual humor used in liquor advertisements to determine if one was more effective than the other in attracting male magazine readers. Thirty-two Starch-scored liquor ads taken from 1976 and 1977 issues of "Time,""Newsweek," and "Sports Illustrated" were analyzed by three male readers.…

Self-ratings of physical attractiveness in a competitive context: when males are more sensitive to self-perceptions than females.

PubMed

Saad, Gad; Gill, Tripat

2009-10-01

The authors investigated sex differences in the ratings of physical attractiveness in a competitive context. Participants in an Ultimatum Game experiment offered to split a sum of money with their opponents who could either accept or reject the offers; subsequently, physical attractiveness ratings (both self-ratings and of the other) were obtained. The authors found that male participants rated themselves higher on physical attractiveness when facing male opponents than when facing female ones; there was no such difference for the female participants. Furthermore, male participants' self-ratings of physical attractiveness were higher than the ratings provided by their corresponding male opponents. The authors discuss these findings using the tenets of evolutionary psychology pertaining to as male intra-sexual rivalry in competitive contexts.

Women's self-rated attraction to male faces does not correspond with physiological arousal.

PubMed

Hagerman, S; Woolard, Z; Anderson, K; Tatler, B W; Moore, F R

2017-10-19

There has been little work to determine whether attractiveness ratings of faces correspond to sexual or more general attraction. We tested whether a measure of women's physiological arousal (pupil diameter change) was correlated with ratings of men's facial attractiveness. In Study 1, women rated the faces of men for whom we also measured salivary testosterone. They rated each face for attractiveness, and for desirability for friendship and long- and short-term romantic relationships. Pupil diameter change was not related to subjective ratings of attractiveness, but was positively correlated with the men's testosterone. In Study 2 we compared women's pupil diameter change in response to the faces of men with high versus low testosterone, as well as in response to non-facial images pre-rated as either sexually arousing or threatening. Pupil dilation was not affected by testosterone, and increased relatively more in response to sexually arousing than threatening images. We conclude that self-rated preferences may not provide a straightforward and direct assessment of sexual attraction. We argue that future work should identify the constructs that are tapped via attractiveness ratings of faces, and support the development of methodology which assesses objective sexual attraction.

Geographic variation in sexual attraction of Spodoptera frugiperda corn- and rice-strain males to pheromone lures

USDA-ARS?s Scientific Manuscript database

The corn- and rice-strains of Spodoptera frugiperda exhibit several genetic and behavioral differences and appear to be undergoing ecological speciation in sympatry. Previous studies reported conflicting results when investigating male attraction to pheromone lures in different regions, but this cou...

Floral visual signal increases reproductive success in a sexually deceptive orchid

PubMed Central

Streinzer, Martin; Paulus, Hannes F.; Spaethe, Johannes

2013-01-01

Sexually deceptive orchids mimic signals emitted by female insects in order to attract mate-searching males. Specific attraction of the targeted pollinator is achieved by sex pheromone mimicry, which constitutes the major attraction channel. In close vicinity of the flower, visual signals may enhance attraction, as was shown recently in the sexually deceptive orchid Ophrys heldreichii. Here, we conducted an in situ manipulation experiment in two populations of O. heldreichii on Crete to investigate whether the presence/absence of the conspicuous pink perianth affects reproductive success in two natural orchid populations. We estimated reproductive success of three treatment groups (with intact, removed and artificial perianth) throughout the flowering period as pollinaria removal (male reproductive success) and massulae deposition (female reproductive success). Reproductive success was significantly increased by the presence of a strong visual signal—the conspicuous perianth—in one study population, however, not in the second, most likely due to the low pollinator abundance in the latter population. This study provides further evidence that the coloured perianth in O. heldreichii is adaptive and thus adds to the olfactory signal to maximise pollinator attraction and reproductive success. PMID:23750181

Floral visual signal increases reproductive success in a sexually deceptive orchid.

PubMed

Rakosy, Demetra; Streinzer, Martin; Paulus, Hannes F; Spaethe, Johannes

2012-12-01

Sexually deceptive orchids mimic signals emitted by female insects in order to attract mate-searching males. Specific attraction of the targeted pollinator is achieved by sex pheromone mimicry, which constitutes the major attraction channel. In close vicinity of the flower, visual signals may enhance attraction, as was shown recently in the sexually deceptive orchid Ophrys heldreichii . Here, we conducted an in situ manipulation experiment in two populations of O. heldreichii on Crete to investigate whether the presence/absence of the conspicuous pink perianth affects reproductive success in two natural orchid populations. We estimated reproductive success of three treatment groups (with intact, removed and artificial perianth) throughout the flowering period as pollinaria removal (male reproductive success) and massulae deposition (female reproductive success). Reproductive success was significantly increased by the presence of a strong visual signal-the conspicuous perianth-in one study population, however, not in the second, most likely due to the low pollinator abundance in the latter population. This study provides further evidence that the coloured perianth in O. heldreichii is adaptive and thus adds to the olfactory signal to maximise pollinator attraction and reproductive success.

Quantifying male attractiveness.

PubMed Central

McNamara, John M; Houston, Alasdair I; Marques Dos Santos, Miguel; Kokko, Hanna; Brooks, Rob

2003-01-01

Genetic models of sexual selection are concerned with a dynamic process in which female preference and male trait values coevolve. We present a rigorous method for characterizing evolutionary endpoints of this process in phenotypic terms. In our phenotypic characterization the mate-choice strategy of female population members determines how attractive females should find each male, and a population is evolutionarily stable if population members are actually behaving in this way. This provides a justification of phenotypic explanations of sexual selection and the insights into sexual selection that they provide. Furthermore, the phenotypic approach also has enormous advantages over a genetic approach when computing evolutionarily stable mate-choice strategies, especially when strategies are allowed to be complex time-dependent preference rules. For simplicity and clarity our analysis deals with haploid mate-choice genetics and a male trait that is inherited phenotypically, for example by vertical cultural transmission. The method is, however, easily extendible to other cases. An example illustrates that the sexy son phenomenon can occur when there is phenotypic inheritance of the male trait. PMID:14561306

I'm sexy and I glow it: female ornamentation in a nocturnal capital breeder.

PubMed

Hopkins, Juhani; Baudry, Gautier; Candolin, Ulrika; Kaitala, Arja

2015-10-01

In many species, males rely on sexual ornaments to attract females. Females, by contrast, rarely produce ornaments. The glow-worm (Lampyris noctiluca) is an exception where wingless females glow to attract males that fly in search of females. However, little is known about the factors that promote the evolution of female ornaments in a sexual selection context. Here, we investigated if the female ornament of the glow-worm is a signal of fecundity used in male mate choice. In support of this, we found brightness to correlate with female fecundity, and males to prefer brighter dummy females. Thus, the glow emitted by females is a reliable sexual signal of female fecundity. It is likely that male preference for the fecundity-indicating ornament has evolved because of large variation among females in fecundity, and because nocturnal males cannot directly assess female size and fecundity. These results indicate that female ornamentation may evolve in capital breeders (i.e. those in which stored resources are invested in reproduction) when females vary significantly in fecundity and this variation cannot be assessed directly by males. © 2015 The Author(s).

Telipogon peruvianus (Orchidaceae) Flowers Elicit Pre-Mating Behaviour in Eudejeania (Tachinidae) Males for Pollination.

PubMed

Martel, Carlos; Cairampoma, Lianka; Stauffer, Fred W; Ayasse, Manfred

2016-01-01

Several neotropical orchid genera have been proposed as being sexually deceptive; however, this has been carefully tested in only a few cases. The genus Telipogon has long been assumed to be pollinated by male tachinid flies during pseudocopulatory events but no detailed confirmatory reports are available. Here, we have used an array of methods to elucidate the pollination mechanism in Telipogon peruvianus. The species presents flowers that have a mean floral longevity of 33 days and that are self-compatible, although spontaneous self-pollination does not occur. The flowers attract males of four tachinid species but only the males of an undescribed Eudejeania (Eudejeania aff. browni; Tachinidae) species are specific pollinators. Males visit the flowers during the first few hours of the day and the pollination success is very high (42% in one patch) compared with other sexually deceptive species. Female-seeking males are attracted to the flowers but do not attempt copulation with the flowers, as is usually described in sexually deceptive species. Nevertheless, morphological analysis and behavioural tests have shown an imperfect mimicry between flowers and females suggesting that the attractant stimulus is not based only on visual cues, as long thought. Challenging previous conclusions, our chemical analysis has confirmed that flowers of Telipogon release volatile compounds; however, the role of these volatiles in pollinator behaviour remains to be established. Pollinator behaviour and histological analyses indicate that Telipogon flowers possess scent-producing structures throughout the corolla. Our study provides the first confirmed case of (i) a sexually deceptive species in the Onciidinae, (ii) pollination by pre-copulatory behaviour and (iii) pollination by sexual deception involving tachinid flies.

Telipogon peruvianus (Orchidaceae) Flowers Elicit Pre-Mating Behaviour in Eudejeania (Tachinidae) Males for Pollination

PubMed Central

Cairampoma, Lianka; Stauffer, Fred W.; Ayasse, Manfred

2016-01-01

Several neotropical orchid genera have been proposed as being sexually deceptive; however, this has been carefully tested in only a few cases. The genus Telipogon has long been assumed to be pollinated by male tachinid flies during pseudocopulatory events but no detailed confirmatory reports are available. Here, we have used an array of methods to elucidate the pollination mechanism in Telipogon peruvianus. The species presents flowers that have a mean floral longevity of 33 days and that are self-compatible, although spontaneous self-pollination does not occur. The flowers attract males of four tachinid species but only the males of an undescribed Eudejeania (Eudejeania aff. browni; Tachinidae) species are specific pollinators. Males visit the flowers during the first few hours of the day and the pollination success is very high (42% in one patch) compared with other sexually deceptive species. Female-seeking males are attracted to the flowers but do not attempt copulation with the flowers, as is usually described in sexually deceptive species. Nevertheless, morphological analysis and behavioural tests have shown an imperfect mimicry between flowers and females suggesting that the attractant stimulus is not based only on visual cues, as long thought. Challenging previous conclusions, our chemical analysis has confirmed that flowers of Telipogon release volatile compounds; however, the role of these volatiles in pollinator behaviour remains to be established. Pollinator behaviour and histological analyses indicate that Telipogon flowers possess scent-producing structures throughout the corolla. Our study provides the first confirmed case of (i) a sexually deceptive species in the Onciidinae, (ii) pollination by pre-copulatory behaviour and (iii) pollination by sexual deception involving tachinid flies. PMID:27812201

The role of men's physical attractiveness in women's perceptions of sexual risk: danger or allure?

PubMed

Lennon, Carter A; Kenny, David A

2013-09-01

The rate of casual sexual encounters is increasing on college campuses. To decrease sexual risk behavior, information used to judge sexual risk in others needs to be identified. Women rated male targets on willingness to have unprotected sex with the target and likelihood that the target has a sexually transmitted infection. Physical attractiveness was the strongest predictor of ratings, accounting for all the target variance in willingness to have unprotected sex. However, risk factors reported by the target were inconsistent predictors of perceived sexual risk. Findings are discussed within the context of safer sex interventions for college students.

Have Mischievous Responders Misidentified Sexual Minority Youth Disparities in the National Longitudinal Study of Adolescent to Adult Health?

PubMed

Fish, Jessica N; Russell, Stephen T

2018-05-01

The National Longitudinal Study of Adolescent to Adult Health (Add Health) has been instrumental in identifying sexual minority youth health disparities. Recent commentary suggested that some Wave 1 youth responders, especially males, intentionally mismarked same-sex attraction and, as a result, published reports of health disparities from these data may be suspect. We use two recently developed approaches to identify "jokesters" and mischievous responding and apply them to the Add Health data. First, we show that Wave 1 same-sex attracted youth, including those who later reported completely heterosexual identities in adulthood, were no more likely than different-sex attracted youth and consistently heterosexual participants to be "jokesters." Second, after accounting for mischievous responses, we replicated six previously established disparities: depressive symptoms, suicidal ideation and behaviors, alcohol use, cocaine use, parental satisfaction, and school connectedness. Accounting for mischievousness resulted in the elimination of one observed disparity between heterosexual and sexual minority youth: suicidal ideation for males who reported romantic attraction to both sexes. Results also showed that accounting for mischievous responding may underestimate disparities for sexual minority youth, particularly females. Overall, results presented here support previous studies that identified health disparities among sexual minority youth using these data.

Pheromonally mediated sexual isolation among denning populations of red-sided garter snakes, Thamnophis sirtalis parietalis.

PubMed

Lemaster, Michael P; Mason, Robert T

2003-04-01

Utilizing behavioral experiments and chemical analyses, we examined whether pheromonally mediated sexual isolation exists between denning populations of red-sided garter snakes (Thamtnophis sirtalis parietalis) in Manitoba, Canada. Simultaneous choice tests conducted during the breeding season revealed that adult males from a hibernaculum in central Manitoba displayed a strong courtship preference for females from their own population over females from a hibernaculum in western Manitoba, whereas males from the western Manitoba hibernaculum showed no such preference. In addition. trailing experiments testing the response of males from the two hibernacula to familiar and unfamiliar female trails showed similar results, demonstrating that the observed male preference is mediated through chemical cues. Subsequent chemical analysis of the female sexual attractiveness pheromone. a homologous series of long-chain saturated and (omega-9 cis-unsaturated methyl ketones responsible for eliciting male courtship behavior and trailing behavior in garter snakes, showed significant variation in the composition of the pheromone between the two populations. Specifically, the two populations varied in the relative concentrations of individual unsaturated methyl ketones expressed by females. These results suggest that sexual isolation exists to a degree among denning populations of red-sided garter snakes due to variation in the expression of the female sexual attractiveness pheromone.

Associations Between Environmental Resources and the "Wanting" and "Liking" of Male Song in Female Songbirds.

PubMed

Spool, Jeremy A; Riters, Lauren V

2017-10-01

Reproductive success requires animals to adjust social and sexual behaviors in response to changes in environmental resources. In many species, males produce courtship signals to attract females; however, not all females are attracted by these signals. One possible explanation for this is that environmental resources alter neural mechanisms underlying motivation and reward in females so that male courtship is attractive when conditions are most favorable for an individual to breed. Here, we first introduce resource-dependent breeding behaviors of female songbirds. We then review studies that show associations between neural systems underlying motivation and reward, female responses to male courtship stimuli, and environmental resources necessary for breeding success (e.g., in female starlings, a nest cavity). Overall, we review evidence supporting the working hypotheses that (1) dopamine underlies sexually-motivated female responses to male courtship stimuli (i.e., song), (2) opioids underlie reward induced in females by hearing male courtship song, and (3) these systems are possibly modified by resources such that male courtship song is only attractive and rewarding to females with access to limited environmental resources essential for breeding success. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Preferences for facial and vocal masculinity in homosexual men: the role of relationship status, sexual restrictiveness, and self-perceived masculinity.

PubMed

Valentová, Jaroslava; Roberts, S Craig; Havlícek, Jan

2013-01-01

Studies on mate preferences usually examine heterosexual attraction; comparatively little is known about preferences of individuals whose sexuality is aimed at the same sex. We examined preferences of two groups of androphilic individuals--homosexual men and heterosexual women--for male facial and vocal level of masculinity. Facial images of 58 men and vocal recordings of 30 men were rated by 51 heterosexual women and 33 homosexual men for their attractiveness and masculinity--femininity. In both groups of raters, ratings of vocal attractiveness and masculinity were positively correlated, but there was no overall preference for facial masculinity. After splitting raters according to their relationship status, sexual restrictiveness, and self-rated masculinity, we found significant preferences for masculine voices only in single homosexual men and coupled heterosexual women, while a preference for feminine male faces was found in coupled homosexual men. Furthermore, homosexual men describing themselves as relatively masculine significantly preferred masculine voices but also more feminine male faces. Our results demonstrate that conditional mate preferences are not restricted to heterosexual interactions, and homosexual men prefer a mixture of masculine and feminine traits in their potential male partners.

A lover or a fighter? Opposing sexual selection pressures on men’s vocal pitch and facial hair

PubMed Central

Mackey, Lauren L.; McCarty, Kristofor; Neave, Nick

2016-01-01

The traditional assumption within the research literature on human sexually dimorphic traits has been that many sex differences have arisen from intersexual selection. More recently, however, there has been a shift toward the idea that many male features, including male lower-pitched voices and male beard growth, might have arisen predominantly through intrasexual selection: that is, to serve the purpose of male–male competition instead of mate attraction. In this study, using a unique set of video stimuli, we measured people’s perceptions of the dominance and attractiveness of men who differ both in terms of voice pitch (4 levels from lower to higher pitched) and beard growth (4 levels from clean shaven to a month’s hair growth). We found a nonlinear relationship between lower pitch and increased attractiveness; men’s vocal attractiveness peaked at around 96 Hz. Beard growth had equivocal effects on attractiveness judgments. In contrast, perceptions of men’s dominance simply increased with increasing masculinity (i.e., with lower-pitched voices and greater beard growth). Together, these results suggest that the optimal level of physical masculinity might differ depending on whether the outcome is social dominance or mate attraction. These dual selection pressures might maintain some of the documented variability in male physical and behavioral masculinity that we see today. PMID:27004013

Postnatal nutrition influences male attractiveness and promotes plasticity in male mating preferences

NASA Astrophysics Data System (ADS)

Noguera, José C.; Metcalfe, Neil B.; Monaghan, Pat

2017-12-01

Poor early-life nutrition could reduce adult reproductive success by negatively affecting traits linked to sexual attractiveness such as song complexity. If so, this might favor strategic mate choice, allowing males with less complex songs to tailor their mating tactics to maximize the reproductive benefits. However, this possibility has been ignored in theoretical and empirical studies. By manipulating the micronutrient content of the diet (e.g., low or high) during the postnatal period of male zebra finches, we show for the first time (1) that males reared on a poor (low) micronutrient diet had less complex songs as adults; (2) that these males, in contrast to the high micronutrient diet group, were more selective in their mating strategies, discriminating against those females most likely to reduce their clutch size when paired with males having less complex songs; and (3) that by following different mating strategies, males reared on the contrasting diets obtained similar reproductive benefits. These results suggest that early-life dietary conditions can induce multiple and long-lasting effects on male and female reproductive traits. Moreover, the results seem to reflect a previously unreported case of adaptive plasticity in mate choice in response to a nutritionally mediated reduction in sexual attractiveness.

Evolution of sexual mimicry in the orchid subtribe orchidinae: the role of preadaptations in the attraction of male bees as pollinators

PubMed Central

2008-01-01

Background Within the astonishing diversity of orchid pollination systems, sexual deception is one of the most stunning. An example is the genus Ophrys, where plants attract male bees as pollinators by mimicking female mating signals. Unsaturated hydrocarbons (alkenes) are often the key signal for this chemical mimicry. Here we investigate the evolution of these key compounds within Orchidinae by mapping their production in flowers of selected species onto their estimated phylogeny. Results We found that alkenes, at least in trace amounts, were present in 18 of 20 investigated species together representing 10 genera. Thus, the reconstruction of ancestral state for alkene-production showed that this is a primitive character state in Ophrys, and can be interpreted as a preadaptation for the evolution of sexual deception. Four of the investigated species, namely Ophrys sphegodes, Serapias lingua, S. cordigera, and Anacamptis papilionacea, that are pollinated primarily by male bees, produced significantly larger amounts and a greater number of different alkenes than the species pollinated either primarily by female bees or other insects. Conclusion We suggest that high amounts of alkenes evolved for the attraction of primarily male bees as pollinators by sensory exploitation, and discuss possible driving forces for the evolution of pollination by male bees. PMID:18226206

Evolution of sexual mimicry in the orchid subtribe orchidinae: the role of preadaptations in the attraction of male bees as pollinators.

PubMed

Schiestl, Florian P; Cozzolino, Salvatore

2008-01-28

Within the astonishing diversity of orchid pollination systems, sexual deception is one of the most stunning. An example is the genus Ophrys, where plants attract male bees as pollinators by mimicking female mating signals. Unsaturated hydrocarbons (alkenes) are often the key signal for this chemical mimicry. Here we investigate the evolution of these key compounds within Orchidinae by mapping their production in flowers of selected species onto their estimated phylogeny. We found that alkenes, at least in trace amounts, were present in 18 of 20 investigated species together representing 10 genera. Thus, the reconstruction of ancestral state for alkene-production showed that this is a primitive character state in Ophrys, and can be interpreted as a preadaptation for the evolution of sexual deception. Four of the investigated species, namely Ophrys sphegodes, Serapias lingua, S. cordigera, and Anacamptis papilionacea, that are pollinated primarily by male bees, produced significantly larger amounts and a greater number of different alkenes than the species pollinated either primarily by female bees or other insects. We suggest that high amounts of alkenes evolved for the attraction of primarily male bees as pollinators by sensory exploitation, and discuss possible driving forces for the evolution of pollination by male bees.

Internalized Sexualization and Its Relation to Sexualized Appearance, Body Surveillance, and Body Shame among Early Adolescent Girls

ERIC Educational Resources Information Center

McKenney, Sarah J.; Bigler, Rebecca S.

2016-01-01

Sexually objectifying messages about girls and women are common in U.S. popular culture. As a consequence of exposure to such messages, girls may develop "internalized sexualization," or internalization of the belief that sexual attractiveness to males is an important aspect of their identity. We hypothesized that internalized…

Sex Hormones Function as Sex Attractant Pheromones in House Mice and Brown Rats.

PubMed

Takács, Stephen; Gries, Regine; Gries, Gerhard

2017-07-18

Sex hormones of mammals control the expression of sexual characteristics and bodily functions. The male hormone testosterone and the female hormones progesterone and estradiol are known to occur in urine markings of mice. Here, we show that all three hormones are also present in urine of brown rats, and that they are effective sexual communication signals (pheromones) that elicit attraction behavior of prospective mates in both brown rats and house mice. When added as lures to trap boxes in field experiments, synthetic testosterone, for example, increased captures of adult female mice 15-fold, and a blend of progesterone and estradiol increased captures of male mice eightfold and male rats 13-fold. Remarkably, these hormones increased captures even though the food- and pheromone-based baits to which they were added had previously been shown to be superior to current commercial rodent attractants. We predict that these sex hormones will function as sex attractant pheromones in diverse taxa. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Alterations of male sexual behavior by learned aversions to hamster vaginal secretion.

PubMed

Johnston, R E; Zahorik, D M; Immler, K; Zakon, H

1978-02-01

Male hamsters poisoned after their first adult exposure to the vaginal secretion of female hamsters became hesitant to approach and ingest the secretion. The same aversion-training procedure also altered the responses of males to estrous females, changing the latency, frequency, and duration of a variety of behaviors that are commonly taken as indexes of sexual attraction or arousal and of copulatory performance. The effects suggest that the aversions to vaginal secretion alter the perceived meaning of the secretion for male hamsters, and analysis of the correlations between various measures of sexual arousal and performance support the hypothesis that separate mechanisms underlie the effects of the secretion on appetitive and consummatory sexual behavior.

An Internet study of men sexually attracted to children: Correlates of sexual offending against children.

PubMed

Bailey, J Michael; Bernhard, Paula A; Hsu, Kevin J

2016-10-01

We conducted an Internet survey of 1,102 men sexually attracted to children concerning their history of adjudicated offenses related to child pornography and sexual contact with children. Most of the men reported no offenses, but their rate of offenses was much higher than that expected for adult-attracted men. Correlates of offending are consistent with a strong role of the cumulative effects of temptation, especially age. Older men, men who had repeatedly worked in jobs with children, men who had repeatedly fallen in love with children, and men who had often struggled not to offend were especially likely to have offended. Attraction to male children, relative attraction to children versus adults, and childhood sexual abuse experiences were also strong predictors of offending. In contrast, permissive attitudes regarding child-adult sex and frequent indulgence in sexual fantasies about children were not significantly related to offending. Our findings represent the first large study of offending among men sexually attracted to children who were not recruited via contact with the legal system. Because of methodological limitations, our findings cannot be definitive. Reassuringly, however, results are generally consistent with those from the most pertinent existing studies, of recidivism among convicted sex offenders. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Natural selection stops the evolution of male attractiveness

PubMed Central

Hine, Emma; McGuigan, Katrina; Blows, Mark W.

2011-01-01

Sexual selection in natural populations acts on highly heritable traits and tends to be relatively strong, implicating sexual selection as a causal agent in many phenotypic radiations. Sexual selection appears to be ineffectual in promoting phenotypic divergence among contemporary natural populations, however, and there is little evidence from artificial selection experiments that sexual fitness can evolve. Here, we demonstrate that a multivariate male trait preferred by Drosophila serrata females can respond to selection and results in the maintenance of male mating success. The response to selection was associated with a gene of major effect increasing in frequency from 12 to 35% in seven generations. No further response to selection, or increase in frequency of the major gene, was observed between generations 7 and 11, indicating an evolutionary limit had been reached. Genetic analyses excluded both depletion of genetic variation and overdominance as causes of the evolutionary limit. Relaxing artificial selection resulted in the loss of 52% of the selection response after a further five generations, demonstrating that the response under artificial sexual selection was opposed by antagonistic natural selection. We conclude that male D. serrata sexually selected traits, and attractiveness to D. serrata females conferred by these traits, were held at an evolutionary limit by the lack of genetic variation that would allow an increase in sexual fitness while simultaneously maintaining nonsexual fitness. Our results suggest that sexual selection is unlikely to cause divergence among natural populations without a concomitant change in natural selection, a conclusion consistent with observational evidence from natural populations. PMID:21321197

The mathematics of sexual attraction.

PubMed

Feijó, José A

2010-01-01

Pollen tubes follow attractants secreted by the ovules. In a recent paper in BMC Plant Biology, Stewman and colleagues have quantified the parameters of this attraction and used them to calibrate a mathematical model that reproduces the process and enables predictions on the nature of the female attractant and the mechanisms of the male response.

Interactions among mechanisms of sexual selection on male body size and head shape in a sexually dimorphic fly.

PubMed

Bonduriansky, Russell; Rowe, Locke

2003-09-01

Darwin envisaged male-male and male-female interactions as mutually supporting mechanisms of sexual selection, in which the best armed males were also the most attractive to females. Although this belief continues to predominate today, it has been challenged by sexual conflict theory, which suggests that divergence in the interests of males and females may result in conflicting sexual selection. This raises the empirical question of how multiple mechanisms of sexual selection interact to shape targeted traits. We investigated sexual selection on male morphology in the sexually dimorphic fly Prochyliza xanthostoma, using indices of male performance in male-male and male-female interactions in laboratory arenas to calculate gradients of direct, linear selection on male body size and an index of head elongation. In male-male combat, the first interaction with a new opponent selected for large body size but reduced head elongation, whereas multiple interactions with the same opponent favored large body size only. In male-female interactions, females preferred males with relatively elongated heads, but male performance of the precopulatory leap favored large body size and, possibly, reduced head elongation. In addition, the amount of sperm transferred (much of which is ingested by females) was an increasing function of both body size and head elongation. Thus, whereas both male-male and male-female interactions favored large male body size, male head shape appeared to be subject to conflicting sexual selection. We argue that conflicting sexual selection may be a common result of divergence in the interests of the sexes.

Sexual Arousal Patterns of Autogynephilic Male Cross-Dressers.

PubMed

Hsu, Kevin J; Rosenthal, A M; Miller, David I; Bailey, J Michael

2017-01-01

Men's sexual arousal patterns have been an important window into the nature of their erotic interests. Autogynephilia is a natal male's paraphilic tendency to be sexually aroused by the thought or image of being a woman. Autogynephilic arousal per se is difficult to assess objectively, because it is inwardly focused. However, assessing sexual arousal patterns of autogynephilic males in response to external stimuli is also potentially useful. For example, there is substantial association between autogynephilia and gynandromorphophilia (GAMP), or sexual attraction to gynandromorphs (GAMs), colloquially "she-males." GAMP men's sexual arousal patterns in response to GAM, female, and male stimuli have recently been characterized. In the present study, we extended this understanding by comparing the sexual arousal patterns of autogynephilic male cross-dressers, GAMP men, heterosexual men, and homosexual men. Erotic stimuli included sexually explicit videos of men, women, and GAMs. Autogynephilic men were much more similar in their arousal patterns to heterosexual and GAMP men than to homosexual men. However, similar to GAMP men, autogynephilic men showed increased arousal by GAM stimuli relative to female stimuli compared with heterosexual men.

Genome size variation affects song attractiveness in grasshoppers: evidence for sexual selection against large genomes.

PubMed

Schielzeth, Holger; Streitner, Corinna; Lampe, Ulrike; Franzke, Alexandra; Reinhold, Klaus

2014-12-01

Genome size is largely uncorrelated to organismal complexity and adaptive scenarios. Genetic drift as well as intragenomic conflict have been put forward to explain this observation. We here study the impact of genome size on sexual attractiveness in the bow-winged grasshopper Chorthippus biguttulus. Grasshoppers show particularly large variation in genome size due to the high prevalence of supernumerary chromosomes that are considered (mildly) selfish, as evidenced by non-Mendelian inheritance and fitness costs if present in high numbers. We ranked male grasshoppers by song characteristics that are known to affect female preferences in this species and scored genome sizes of attractive and unattractive individuals from the extremes of this distribution. We find that attractive singers have significantly smaller genomes, demonstrating that genome size is reflected in male courtship songs and that females prefer songs of males with small genomes. Such a genome size dependent mate preference effectively selects against selfish genetic elements that tend to increase genome size. The data therefore provide a novel example of how sexual selection can reinforce natural selection and can act as an agent in an intragenomic arms race. Furthermore, our findings indicate an underappreciated route of how choosy females could gain indirect benefits. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

Sex differences in adults' relative visual interest in female and male faces, toys, and play styles.

PubMed

Alexander, Gerianne M; Charles, Nora

2009-06-01

An individual's reproductive potential appears to influence response to attractive faces of the opposite sex. Otherwise, relatively little is known about the characteristics of the adult observer that may influence his or her affective evaluation of male and female faces. An untested hypothesis (based on the proposed role of attractive faces in mate selection) is that most women would show greater interest in male faces whereas most men would show greater interest in female faces. Further, evidence from individuals with preferences for same-sex sexual partners suggests that response to attractive male and female faces may be influenced by gender-linked play preferences. To test these hypotheses, visual attention directed to sex-linked stimuli (faces, toys, play styles) was measured in 39 men and 44 women using eye tracking technology. Consistent with our predictions, men directed greater visual attention to all male-typical stimuli and visual attention to male and female faces was associated with visual attention to gender conforming or nonconforming stimuli in a manner consistent with previous research on sexual orientation. In contrast, women showed a visual preference for female-typical toys, but no visual preference for male faces or female-typical play styles. These findings indicate that sex differences in visual processing extend beyond stimuli associated with adult sexual behavior. We speculate that sex differences in visual processing are a component of the expression of gender phenotypes across the lifespan that may reflect sex differences in the motivational properties of gender-linked stimuli.

Promiscuity drives sexual selection in a socially monogamous bird.

PubMed

Webster, Michael S; Tarvin, Keith A; Tuttle, Elaina M; Pruett-Jones, Stephen

2007-09-01

Many socially monogamous species paradoxically show signs of strong sexual selection, suggesting cryptic sources of sexual competition among males. Darwin argued that sexual selection could operate in monogamous systems if breeding sex ratios are biased or if some males attract highly fecund females. Alternatively, sexual selection might result from promiscuous copulations outside the pair bond, although several recent studies have cast doubt on this possibility, in particular by showing that variance in apparent male reproductive success (number of social young) differs little from variance in actual male reproductive success (number of young sired). Our results from a long-term study of the socially monogamous splendid fairy-wren (Malurus splendens) demonstrate that such comparisons are misleading and do not adequately assess the effects of extra-pair paternity (EPP). By partitioning the opportunity for selection and calculating Bateman gradients, we show that EPP has a strong effect on male annual and lifetime fitness, whereas other proposed mechanisms of sexual selection do not. Thus, EPP drives sexual selection in this, and possibly other, socially monogamous species.

Sexual Conflict and Gender Gap Effects: Associations between Social Context and Sex on Rated Attractiveness and Economic Status

PubMed Central

Dixson, Barnaby J.

2016-01-01

Human mate choice research often concerns sex differences in the importance of traits such as physical attractiveness and social status. A growing number of studies indicate that cues to social context, including other people who appear in stimulus photographs, can alter that individual’s attractiveness. Fewer studies, however, consider judgements of traits other than physical attractiveness, such as wealth. Here we manipulate the presence/absence of other people in photographs of target models, and test the effects on judgments of both attractiveness and earnings (a proxy for status). Participants (N = 2044) rated either male or female models for either physical attractiveness or social/economic status when presented alone, with same sex others or with opposite sex others. We collectively refer to this manipulation as ‘social context’. Male and female models received similar responses for physical attractiveness, but social context affected ratings of status differently for women and men. Males presented alongside other men received the highest status ratings while females presented alone were given the highest status ratings. Further, the status of females presented alongside a male was constrained by the rated status of that male. Our results suggests that high status may not directly lead to high attractiveness in men, but that status is more readily attributed to men than to women. This divide in status between the sexes is very clear when men and women are presented together, possibly reflecting one underlying mechanism of the modern day gender gap and sexist attitudes to women’s economic participation. This adds complexity to our understanding of the relationship between attractiveness, status, and sex in the light of parental investment theory, sexual conflict and economic theory. PMID:26731414

Sexual Conflict and Gender Gap Effects: Associations between Social Context and Sex on Rated Attractiveness and Economic Status.

PubMed

Gouda-Vossos, Amany; Dixson, Barnaby J; Brooks, Robert C

2016-01-01

Human mate choice research often concerns sex differences in the importance of traits such as physical attractiveness and social status. A growing number of studies indicate that cues to social context, including other people who appear in stimulus photographs, can alter that individual's attractiveness. Fewer studies, however, consider judgements of traits other than physical attractiveness, such as wealth. Here we manipulate the presence/absence of other people in photographs of target models, and test the effects on judgments of both attractiveness and earnings (a proxy for status). Participants (N = 2044) rated either male or female models for either physical attractiveness or social/economic status when presented alone, with same sex others or with opposite sex others. We collectively refer to this manipulation as 'social context'. Male and female models received similar responses for physical attractiveness, but social context affected ratings of status differently for women and men. Males presented alongside other men received the highest status ratings while females presented alone were given the highest status ratings. Further, the status of females presented alongside a male was constrained by the rated status of that male. Our results suggests that high status may not directly lead to high attractiveness in men, but that status is more readily attributed to men than to women. This divide in status between the sexes is very clear when men and women are presented together, possibly reflecting one underlying mechanism of the modern day gender gap and sexist attitudes to women's economic participation. This adds complexity to our understanding of the relationship between attractiveness, status, and sex in the light of parental investment theory, sexual conflict and economic theory.

Prenatal programming of sexual partner preference: the ram model.

PubMed

Roselli, C E; Stormshak, F

2009-03-01

In our laboratory, the domestic ram is used as an experimental model to study the early programming of neural mechanisms underlying same-sex partner preference. This interest developed from the observation that approximately 8% of domestic rams are sexually attracted to other rams (male-oriented) in contrast to the majority of rams that are attracted to oestrous ewes (female-oriented). One prominent feature of sexual differentiation in many species is the presence of a sexually dimorphic nucleus (SDN) in the preoptic/anterior hypothalamus that is larger in males than in females. Lesion studies in rats and ferrets implicate the SDN in the expression of sexual preferences. We discovered an ovine SDN (oSDN) in the preoptic/anterior hypothalamus that is smaller in male- than in female-oriented rams and similar in size to the oSDN of ewes. Neurones of the oSDN show abundant aromatase expression that is also reduced in male-oriented compared to female-oriented rams. This observation suggests that sexual partner preferences are neurologically hard-wired and could be influenced by hormones. Aromatase-containing neurones constitute a nascent oSDN as early as day 60 of gestation, which becomes sexually dimorphic by day 135 of gestation when it is two-fold larger in males than in females. Exposure of fetal female lambs to exogenous testosterone from days 30-90 of gestation resulted in a masculinised oSDN. These data demonstrate that the oSDN develops prenatally and may influence adult sexual preferences. Surprisingly, inhibition of aromatase activity in the brain of ram foetuses during the critical period did not interfere with defeminisation of adult sexual partner preference or oSDN volume. These results fail to support an essential role for neural aromatase in the sexual differentiation of sheep brain and behaviour. Thus, we propose that oSDN morphology and male-typical partner preferences may instead be programmed through an androgen receptor mechanism not involving aromatisation.

Men's sexual orientation and suicide: evidence for U.S. adolescent-specific risk.

PubMed

Russell, Stephen T; Toomey, Russell B

2012-02-01

There is strong consensus in the research literature that adolescent and adult men who report same-sex sexual orientations, identities, and behaviors are at higher risk for suicide. Recent studies of general adolescent suicide risk have identified developmental trajectories that peak during the teenage years. Because the adolescent years are characterized by the development and heightened awareness of gender roles and sexual scripts closely tied to dominant cultural ideals of masculinity and heterosexuality, an adolescent-focused developmental trajectory for suicide risk might be particularly relevant for males with adolescent same-sex sexual orientations. We provide the first prospective examination of adolescent-specific risk for suicidality based on adolescent same-sex sexual orientation using data from the United States, the National Longitudinal Study of Adolescent Health. Tracing suicide ideation and attempts across four assessments from adolescence (Wave 1 average age 15.3 years) to young adulthood (Wave 4 average age 28.2), we documented that the risk for suicidal thoughts and attempts for adolescent same-sex attracted males is developmental in nature. Specifically, the risk for suicidal thoughts and attempts for males with same-sex attractions is largely limited to the adolescent years. These results offer new insights for suicide prevention and intervention for male adolescents and adults with same-sex sexual orientations. Copyright © 2010 Elsevier Ltd. All rights reserved.

Adolescents Define Sexual Orientation and Suggest Ways to Measure It

ERIC Educational Resources Information Center

Friedman, M. S. Mark S.; Silvestre, Anthony J.; Gold, Melanie A.; Markovic, Nina; Savin-Williams, Ritch C.; Huggins, James; Sell, Randal L.

2004-01-01

Researchers disagree on how to assess adolescent sexual orientation. The relative importance of various dimensions (e.g. attraction, relationships, behavior, self-labeling) is unknown, which calls into question the validity of studies assessing adolescent sexual orientation. To address this issue, 50 male and female adolescents of varied sexual…

An exploratory study of the categorical versus spectrum nature of sexual orientation.

PubMed

Savin-Williams, Ritch C

2014-01-01

This exploratory study investigated the nature of sexual orientation (categorical or spectrum) by assessing the relative ability of sexual and romantic indicators to be predicted by sexual orientation labels. Young adults from a variety of community and college venues (N =292) reported their sexual orientation label on a 9-point scale; from a 10-item list, their sexual identity; and the percentage of their sexual attraction, fantasy, genital contact, infatuation, and romantic relationship directed to males and females. Although the five indicators were significantly intercorrelated and sexual orientation labels predicted each indicator, discrepancies existed across indicators in relationship to sexual orientation (highest for attraction, lowest for romantic relationship). Sexual identity and sexual orientation label were strongly related at the ends of the sexual spectrum, less so in the middle. Men were nearly as nonexclusive as women. Study results supported the perspective that sexual orientation is a continuously distributed individual characteristic.

Concentrating on beauty: sexual selection and sociospatial memory.

PubMed

Becker, D Vaughn; Kenrick, Douglas T; Guerin, Stephen; Maner, Jon K

2005-12-01

In three experiments, location memory for faces was examined using a computer version of the matching game Concentration. Findings suggested that physical attractiveness led to more efficient matching for female faces but not for male faces. Study 3 revealed this interaction despite allowing participants to initially see, attend to, and match the attractive male faces in the first few turns. Analysis of matching errors suggested that, compared to other targets, attractive women were less confusable with one another. Results are discussed in terms of the different functions that attractiveness serves for men and women.

Barely legal: is attraction and estimated age of young female faces disrupted by alcohol use, make up, and the sex of the observer?

PubMed

Egan, Vincent; Cordan, Giray

2009-05-01

One 'reasonable ground' for unlawful sex with a minor is mistaken age. Alcohol consumption and make-up are often deemed further influences on impaired perception. Two hundred and forty persons in bars and cafes rated the attractiveness of composite faces of immature and mature females with and without additional makeup, alcohol users having their concurrent blood-alcohol level measured using a breathalyser. A non-sex-specific preference for immature faces over sexually mature faces was found. Alcohol and make-up did not inflate attractiveness ratings in immature faces. While alcohol consumption significantly inflated attractiveness ratings for participants viewing made-up sexually mature faces, greater alcohol consumption itself did not lead to overestimation of age. Although alcohol limited the processing of maturity cues in female observers, it had no effect on the age perceptions of males viewing female faces, suggesting male mate preferences are not easily disrupted. Participants consistently overestimated the age of sexually immature- and sexually mature-faces by an average of 3.5 years. Our study suggests that even heavy alcohol consumption does not interfere with age-perception tasks in men, so is not of itself an excuse for apparent mistaken age in cases of unlawful sex with a minor.

Predictors of facial attractiveness and health in humans.

PubMed

Foo, Yong Zhi; Simmons, Leigh W; Rhodes, Gillian

2017-02-03

Facial attractiveness has been suggested to provide signals of biological quality, particularly health, in humans. The attractive traits that have been implicated as signals of biological quality include sexual dimorphism, symmetry, averageness, adiposity, and carotenoid-based skin colour. In this study, we first provide a comprehensive examination of the traits that predict attractiveness. In men, attractiveness was predicted positively by masculinity, symmetry, averageness, and negatively by adiposity. In women, attractiveness was predicted positively by femininity and negatively by adiposity. Skin colour did not predict attractiveness in either sex, suggesting that, despite recent interest in the literature, colour may play limited role in determining attractiveness. Male perceived health was predicted positively by averageness, symmetry, and skin yellowness, and negatively by adiposity. Female perceived health was predicted by femininity. We then examined whether appearance predicted actual health using measures that have been theoretically linked to sexual selection, including immune function, oxidative stress, and semen quality. In women, there was little evidence that female appearance predicted health. In men, we found support for the phenotype-linked fertility hypothesis that male masculinity signalled semen quality. However, we also found a negative relationship between averageness and semen quality. Overall, these results indicate weak links between attractive facial traits and health.

Predictors of facial attractiveness and health in humans

PubMed Central

Foo, Yong Zhi; Simmons, Leigh W.; Rhodes, Gillian

2017-01-01

Facial attractiveness has been suggested to provide signals of biological quality, particularly health, in humans. The attractive traits that have been implicated as signals of biological quality include sexual dimorphism, symmetry, averageness, adiposity, and carotenoid-based skin colour. In this study, we first provide a comprehensive examination of the traits that predict attractiveness. In men, attractiveness was predicted positively by masculinity, symmetry, averageness, and negatively by adiposity. In women, attractiveness was predicted positively by femininity and negatively by adiposity. Skin colour did not predict attractiveness in either sex, suggesting that, despite recent interest in the literature, colour may play limited role in determining attractiveness. Male perceived health was predicted positively by averageness, symmetry, and skin yellowness, and negatively by adiposity. Female perceived health was predicted by femininity. We then examined whether appearance predicted actual health using measures that have been theoretically linked to sexual selection, including immune function, oxidative stress, and semen quality. In women, there was little evidence that female appearance predicted health. In men, we found support for the phenotype-linked fertility hypothesis that male masculinity signalled semen quality. However, we also found a negative relationship between averageness and semen quality. Overall, these results indicate weak links between attractive facial traits and health. PMID:28155897

Estimating the Sex-Specific Effects of Genes on Facial Attractiveness and Sexual Dimorphism

PubMed Central

Purkey, Alicia M.; Grebe, Nicholas M.; Carey, Gregory; Garver-Apgar, Christine E.; Bates, Timothy C.; Arden, Rosalind; Hewitt, John K.; Medland, Sarah E.; Martin, Nicholas G.; Zietsch, Brendan P.; Keller, Matthew C.

2014-01-01

Human facial attractiveness and facial sexual dimorphism (masculinity–femininity) are important facets of mate choice and are hypothesized to honestly advertise genetic quality. However, it is unclear whether genes influencing facial attractiveness and masculinity–femininity have similar, opposing, or independent effects across sex, and the heritability of these phenotypes is poorly characterized. To investigate these issues, we assessed facial attractiveness and facial masculinity–femininity in the largest genetically informative sample (n = 1,580 same- and opposite-sex twin pairs and siblings) to assess these questions to date. The heritability was ~0.50–0.70 for attractiveness and ~0.40–0.50 for facial masculinity– femininity, indicating that, despite ostensible selection on genes influencing these traits, substantial genetic variation persists in both. Importantly, we found evidence for intralocus sexual conflict, whereby alleles that increase masculinity in males have the same effect in females. Additionally, genetic influences on attractiveness were shared across the sexes, suggesting that attractive fathers tend to have attractive daughters and attractive mothers tend to have attractive sons. PMID:24213680

Prevalence and correlates of smoking and e-cigarette use among young men who have sex with men and transgender women.

PubMed

Gerend, Mary A; Newcomb, Michael E; Mustanski, Brian

2017-10-01

Although the prevalence of cigarette smoking in the United States has decreased, rates remain elevated among sexual and gender minorities (SGMs). This study examined rates and correlates of tobacco use among young men who have sex with men (YMSM) and transgender women. Participants (N=771) were drawn from the baseline assessment of an ongoing longitudinal cohort study of racially diverse MSM aged 16-29 years. Data collection took place in 2015-2016. Socio-demographic and SGM-specific (e.g., gender identity, sexual identity, physical attraction) correlates of cigarette smoking and electronic cigarette (e-cigarette) use were identified using logistic regression. Twenty-one percent were current cigarette smokers. Nearly 40% ever tried an e-cigarette, but regular e-cigarette use was low (3.8%). Smokers were more likely to be older (vs. aged 16-18), less educated, homeless, bisexual or identify as some other sexual minority (vs. gay), attracted to males and females equally or more attracted to females than males (vs. males only), and HIV-positive. E-cigarette users were more likely to be transgender women (vs. cisgender men), White (vs. Black), more educated, and mostly attracted to females. Findings highlight important risk factors for tobacco use among SGM youth. Correlates of smoking mirrored findings observed in the general population, but also included factors specific to SGM youth (e.g., sexual orientation, HIV status, homelessness). Although some variables (gender identity, attraction) demonstrated similar relationships with smoking and e-cigarette use, others (race/ethnicity, education) demonstrated opposite patterns. Findings underscore the urgent need for tobacco prevention and cessation interventions for SGM youth. Copyright © 2017 Elsevier B.V. All rights reserved.

Sexual identity trajectories among sexual-minority youths: gender comparisons.

PubMed

Savin-Williams, R C; Diamond, L M

2000-12-01

The present investigation explored gender differences in sexual identity development--first same-sex attractions, self-labeling, same-sex sexual contact, and disclosure--among 164 sexual-minority young adults. Based on interviews, results indicated the value of assessing gender differences in the context, timing, spacing, and sequencing of sexual identity milestones. Adolescent males had an earlier onset of all milestones except disclosure. The context for sexual identity milestones were likely to be emotionally oriented for young women and sexually oriented for young men. The gap from first same-sex attractions (8-9 years of age) to first disclosure (around 18 years) averaged 10 years for both sexes. Young women followed label-first developmental trajectories; men were more likely to pursue sex before identifying themselves as gay. In terms of achieving sexual identity milestones, gender mattered, but it was not everything.

A qualitative analysis of the temptation to use force in sexual relationships.

PubMed

Schewe, Paul A; Adam, Najma M; Ryan, Kathryn M

2009-01-01

College males completed a survey that asked open-ended questions concerning instances in which they might have been tempted to use force to obtain sexual contact with another person. Participants also completed Malamuth's (1989a, 1989b) Attraction to Sexual Aggression scale, Mosher and Sirkin's (1984) Hypermasculinity Inventory. and Burt's (1980) Rape Myth Acceptance and Adversarial Sexual Beliefs scales. Of the 83 participants, 22 (27%) reported that they had been tempted to use force. Participants that indicated they had been tempted to use force scored significantly higher on attraction to sexual aggression and hypermasculinity than those who were never tempted. Reasons for temptation, circumstances of the tempting situations, and possible ties to sexual coercion were explored.

Sexual selection of male parental care in giant water bugs

PubMed Central

Ohba, Shin-ya; Okuda, Noboru; Kudo, Shin-ichi

2016-01-01

Paternal care can be maintained under sexual selection, if it helps in attracting more mates. We tested the hypothesis in two giant water bug species, Appasus major and Appasus japonicus, that male parental care is sexually selected through female preference for caring males. Females were given an opportunity to choose between two males. In the first test of female mate choice, one male carried eggs on its back, while the other did not. The egg status was switched between these two males in the second test. The experiment revealed that females of both species preferred caring males (i.e. egg-bearing) to non-caring males. Nonetheless, the female mate preference for egg-bearing males was stronger in A. major than in A. japonicus. Our results suggest that sexual selection plays an important role in maintaining elaborate paternal care in giant water bugs, but the importance of egg-bearing by males in female mate choice varies among species. PMID:27293778

Man-boy lovers: assessment, counseling, and psychotherapy.

PubMed

van Naerssen, A

1990-01-01

Clinical experiences with 36 males, between the ages of 21 and 60 are described. All of them felt an enduring sexual attraction for boys. Sixteen males were treated for sexual identity conflicts. For eight of them this ended in a positive self-labeling as pedophile, the others had severe problems with accepting sexuality as positive and lustful. Twenty males were treated for identity management problems and counseled how to handle their relationships with boys. Several modalities of interpersonal interaction in man-boy relationships are proposed and the ways conflicts can arise within these frames of reference are explored in counseling and psychotherapy.

The Specificity of Women's Sexual Response and Its Relationship with Sexual Orientations: A Review and Ten Hypotheses.

PubMed

Chivers, Meredith L

2017-07-01

Category-specific sexual response describes a pattern wherein the individual shows significantly greater responses to preferred versus nonpreferred categories of sexual stimuli; this pattern is described as gender specific for sexual orientation to gender, or gender nonspecific if lacking response differentiation by gender cues. Research on the gender specificity of women's sexual response has consistently produced sexual orientation effects, such that androphilic women (sexually attracted to adult males) typically show gender-nonspecific patterns of genital response and gynephilic women (sexually attracted to adult females) show more gender-specific responses. As research on the category specificity of sexual response has grown, this pattern has also been observed for other measures of sexual response. In this review, I use the Incentive Motivation and Information Processing Models as complementary frameworks to organize the empirical literature examining the gender specificity of women's sexual response at each stage of sexual stimulus processing and response. Collectively, these data disconfirm models of sexual orientation that equate androphilic women's sexual attractions with their sexual responses to sexual stimuli. I then discuss 10 hypotheses that might explain variability in the specificity of sexual response among androphilic and gynephilic women, and conclude with recommendations for future research on the (non)specificity of sexual response.

Virgin queen attraction toward males in honey bees.

PubMed

Bastin, Florian; Cholé, Hanna; Lafon, Grégory; Sandoz, Jean-Christophe

2017-07-24

Although the honeybee is a crucial agricultural agent and a prominent scientific model organism, crucial aspects of its reproductive behaviour are still unknown. During the mating season, honeybee males, the drones, gather in congregations 10-40 m above ground. Converging evidence suggests that drones emit a pheromone that can attract other drones, thereby increasing the size of the congregation. Virgin queens join the vicinity of the congregation after it has formed, and mate with as many as 20 males in mid-air. It is still unclear which sensory cues help virgin queens find drone congregations in the first place. Beside visual cues for long-range orientation, queens may use olfactory cues. We thus tested virgin queens' olfactory orientation on a walking simulator in which they have full control over odour stimulation. We show that sexually-mature virgin queens are attracted to the odour bouquet from a group of living drones. They are not attracted to the bouquet from a group of workers. In addition, non-sexually receptive females (workers) of the same age are not attracted to the drone odour bouquet. Interpreted in the context of mating, these results may suggest that virgin queens use volatile olfactory cues from the drones to find the congregations.

Female brain size affects the assessment of male attractiveness during mate choice.

PubMed

Corral-López, Alberto; Bloch, Natasha I; Kotrschal, Alexander; van der Bijl, Wouter; Buechel, Severine D; Mank, Judith E; Kolm, Niclas

2017-03-01

Mate choice decisions are central in sexual selection theory aimed to understand how sexual traits evolve and their role in evolutionary diversification. We test the hypothesis that brain size and cognitive ability are important for accurate assessment of partner quality and that variation in brain size and cognitive ability underlies variation in mate choice. We compared sexual preference in guppy female lines selected for divergence in relative brain size, which we have previously shown to have substantial differences in cognitive ability. In a dichotomous choice test, large-brained and wild-type females showed strong preference for males with color traits that predict attractiveness in this species. In contrast, small-brained females showed no preference for males with these traits. In-depth analysis of optomotor response to color cues and gene expression of key opsins in the eye revealed that the observed differences were not due to differences in visual perception of color, indicating that differences in the ability to process indicators of attractiveness are responsible. We thus provide the first experimental support that individual variation in brain size affects mate choice decisions and conclude that differences in cognitive ability may be an important underlying mechanism behind variation in female mate choice.

Ovulatory Shifts in Women’s Attractions to Primary Partners and Other Men: Further Evidence of the Importance of Primary Partner Sexual Attractiveness

PubMed Central

2012-01-01

Previous research has documented shifts in women’s attractions to their romantic partner and to men other than their partner across the ovulation cycle, contingent on the degree to which her partner displays hypothesized indicators of high-fitness genes. The current study set out to replicate and extend this finding. Forty-one couples in which the woman was naturally cycling participated. Female partners reported their feelings of in-pair attraction and extra-pair attraction on two occasions, once on a low-fertility day of the cycle and once on a high-fertility day of the cycle just prior to ovulation. Ovulation was confirmed using luteinizing hormone tests. We collected two measures of male partner sexual attractiveness. First, the women in the study rated their partner’s sexual attractiveness. Second, we photographed the partners and had the photos independently rated for attractiveness. Shifts in women’s in-pair attractions across the cycle were significantly moderated by women’s ratings of partner sexual attractiveness, such that the less sexually attractive women rated their partner, the less in-pair attraction they reported at high fertility compared with low fertility (partial r = .37, p dir = .01). Shifts in women’s extra-pair attractions across the cycle were significantly moderated by third-party ratings of partner attractiveness, such that the less attractive the partner was, the more extra-pair attraction women reported at high relative to low fertility (partial r = −.33, p dir = .03). In line with previous findings, we found support for the hypothesis that the degree to which a woman’s romantic partner displays indicators of high-fitness genes affects women’s attractions to their own partner and other men at high fertility. PMID:22984512

The Sexual Orientation and Gender Presentation of Hijra, Kothi, and Panthi in Mumbai, India.

PubMed

Stief, Matthew

2017-01-01

Cultural categories related to sexuality and gender vary considerably cross-culturally. While Western cultures categorize people primarily in terms of sexual attractions (i.e., gay, straight, bisexual), many cultures distinguish between groups based on additional issues such as gender role presentation and position preference in anal sex (i.e., insertive/receptive). The current study gathered data on three categories of natal males in Mumbai, India-hijra, kothi, and panthi (N = 93). Hijra are androphilic (sexually attracted to adult men), typically sexually receptive, transgender, sometimes castrated, and live in fictive kinship networks that are hierarchically organized. Kothi are also androphilic, typically sexual receptive and relatively feminine but less so than hijra; unlike hijra, kothi are never castrated. Hijra and kothi were understood by some participants to be mutually compatible, and so three groups were identified-those endorsing hijra only (n = 11), kothi only (n = 22), and both hijra and kothi (n = 22). Panthi (n = 38) are the masculine insertive partners of hijra and kothi. Measures employed were self-report and viewing time measures of sexual attraction, sexual behavior and position preference, self-described masculinity/femininity, recalled childhood gender atypicality, gendered occupational preferences, and gender presentation milestones (i.e., wearing female clothes, castration). All hijra and kothi groups were found to be exclusively androphilic in viewing time and self-reported sexual attractions, and to be gender-atypical on all measures. Panthi were found to be relatively male-typical and to have a bisexual pattern of viewing time and self-reported sexual attractions. Kothi were found to be less extreme in their female typicality and to report less female gender presentation milestones than hijra or hijra/kothi. Most hijra and hijra/kothi and all kothi said that they were not castrated. Contrary to the manner in which they are socially defined, a third of panthi report having been receptive in anal sex, and a third of all hijra and kothi groups report having been insertive at some time.

Glutamate and Opioid Antagonists Modulate Dopamine Levels Evoked by Innately Attractive Male Chemosignals in the Nucleus Accumbens of Female Rats

PubMed Central

Sánchez-Catalán, María-José; Orrico, Alejandro; Hipólito, Lucía; Zornoza, Teodoro; Polache, Ana; Lanuza, Enrique; Martínez-García, Fernando; Granero, Luis; Agustín-Pavón, Carmen

2017-01-01

Sexual chemosignals detected by vomeronasal and olfactory systems mediate intersexual attraction in rodents, and act as a natural reinforcer to them. The mesolimbic pathway processes natural rewards, and the nucleus accumbens receives olfactory information via glutamatergic projections from the amygdala. Thus, the aim of this study was to investigate the involvement of the mesolimbic pathway in the attraction toward sexual chemosignals. Our data show that female rats with no previous experience with males or their chemosignals display an innate preference for male-soiled bedding. Focal administration of the opioid antagonist β-funaltrexamine into the posterior ventral tegmental area does not affect preference for male chemosignals. Nevertheless, exposure to male-soiled bedding elicits an increase in dopamine efflux in the nucleus accumbens shell and core, measured by microdialysis. Infusion of the opioid antagonist naltrexone in the accumbens core does not significantly affect dopamine efflux during exposure to male chemosignals, although it enhances dopamine levels 40 min after withdrawal of the stimuli. By contrast, infusion of the glutamate antagonist kynurenic acid in the accumbens shell inhibits the release of dopamine and reduces the time that females spend investigating male-soiled bedding. These data are in agreement with previous reports in male rats showing that exposure to opposite-sex odors elicits dopamine release in the accumbens, and with data in female mice showing that the behavioral preference for male chemosignals is not affected by opioidergic antagonists. We hypothesize that glutamatergic projections from the amygdala into the accumbens might be important to modulate the neurochemical and behavioral responses elicited by sexual chemosignals in rats. PMID:28280461

Glutamate and Opioid Antagonists Modulate Dopamine Levels Evoked by Innately Attractive Male Chemosignals in the Nucleus Accumbens of Female Rats.

PubMed

Sánchez-Catalán, María-José; Orrico, Alejandro; Hipólito, Lucía; Zornoza, Teodoro; Polache, Ana; Lanuza, Enrique; Martínez-García, Fernando; Granero, Luis; Agustín-Pavón, Carmen

2017-01-01

Sexual chemosignals detected by vomeronasal and olfactory systems mediate intersexual attraction in rodents, and act as a natural reinforcer to them. The mesolimbic pathway processes natural rewards, and the nucleus accumbens receives olfactory information via glutamatergic projections from the amygdala. Thus, the aim of this study was to investigate the involvement of the mesolimbic pathway in the attraction toward sexual chemosignals. Our data show that female rats with no previous experience with males or their chemosignals display an innate preference for male-soiled bedding. Focal administration of the opioid antagonist β-funaltrexamine into the posterior ventral tegmental area does not affect preference for male chemosignals. Nevertheless, exposure to male-soiled bedding elicits an increase in dopamine efflux in the nucleus accumbens shell and core, measured by microdialysis. Infusion of the opioid antagonist naltrexone in the accumbens core does not significantly affect dopamine efflux during exposure to male chemosignals, although it enhances dopamine levels 40 min after withdrawal of the stimuli. By contrast, infusion of the glutamate antagonist kynurenic acid in the accumbens shell inhibits the release of dopamine and reduces the time that females spend investigating male-soiled bedding. These data are in agreement with previous reports in male rats showing that exposure to opposite-sex odors elicits dopamine release in the accumbens, and with data in female mice showing that the behavioral preference for male chemosignals is not affected by opioidergic antagonists. We hypothesize that glutamatergic projections from the amygdala into the accumbens might be important to modulate the neurochemical and behavioral responses elicited by sexual chemosignals in rats.

Selective attention toward female secondary sexual color in male rhesus macaques.

PubMed

Waitt, Corri; Gerald, Melissa S; Little, Anthony C; Kraiselburd, Edmundo

2006-07-01

Pink-to-red anogenital and facial sexual skin occurs in females of many primate species. Since female sexual skin color varies with reproductive state, it has long been assumed that color acts to stimulate male sexual interest. Although there is supportive evidence for this as regards anogenital skin, it is unclear whether this is also the case for facial sexual skin. In this study we experimentally manipulated digital facial and hindquarter images of female rhesus macaques (Macaca mulatta) for color within the natural range of variation. The images were presented to adult male conspecifics to assess whether the males exhibited visual preferences for red vs. non-red female coloration, and whether preferences varied with anatomical region. The males displayed significantly longer gaze durations in response to reddened versions of female hindquarters, but not to reddened versions of faces. This suggests that female facial coloration may serve an alternative purpose to that of attracting males, and that the signal function of sexual skin and the intended recipients may vary across anatomical regions. (c) 2005 Wiley-Liss, Inc.

Correlational selection leads to genetic integration of body size and an attractive plumage trait in dark-eyed juncos.

PubMed

McGlothlin, Joel W; Parker, Patricia G; Nolan, Val; Ketterson, Ellen D

2005-03-01

When a trait's effect on fitness depends on its interaction with other traits, the resultant selection is correlational and may lead to the integration of functionally related traits. In relation to sexual selection, when an ornamental trait interacts with phenotypic quality to determine mating success, correlational sexual selection should generate genetic correlations between the ornament and quality, leading to the evolution of honest signals. Despite its potential importance in the evolution of signal honesty, correlational sexual selection has rarely been measured in natural populations. In the dark-eyed junco (Junco hyemalis), males with experimentally elevated values of a plumage trait (whiteness in the tail or "tail white") are more attractive to females and dominant in aggressive encounters over resources. We used restricted maximum-likelihood analysis of a long-term dataset to measure the heritability of tail white and two components of body size (wing length and tail length), as well as genetic correlations between pairs of these traits. We then used multiple regression to assess directional, quadratic, and correlational selection as they acted on tail white and body size via four components of lifetime fitness (juvenile and adult survival, mating success, and fecundity). We found a positive genetic correlation between tail white and body size (as measured by wing length), which indicates past correlational selection. Correlational selection, which was largely due to sexual selection on males, was also found to be currently acting on the same pair of traits. Larger males with whiter tails sired young with more females, most likely due to a combination of female choice, which favors males with whiter tails, and male-male competition, which favors both tail white and larger body size. To our knowledge, this is the first study to show both genetic correlations between sexually selected traits and currently acting correlational sexual selection, and we suggest that correlational sexual selection frequently may be an important mechanism for maintaining the honesty of sexual signals.

Sexual Selection on male cuticular hydrocarbons via male-male competition and female choice.

PubMed

Lane, S M; Dickinson, A W; Tregenza, T; House, C M

2016-07-01

Traditional views of sexual selection assumed that male-male competition and female mate choice work in harmony, selecting upon the same traits in the same direction. However, we now know that this is not always the case and that these two mechanisms often impose conflicting selection on male sexual traits. Cuticular hydrocarbons (CHCs) have been shown to be linked to both social dominance and male attractiveness in several insect species. However, although several studies have estimated the strength and form of sexual selection imposed on male CHCs by female mate choice, none have established whether these chemical traits are also subject to sexual selection via male-male competition. Using a multivariate selection analysis, we estimate and compare sexual selection exerted by male-male competition and female mate choice on male CHC composition in the broad-horned flour beetle Gnatocerus cornutus. We show that male-male competition exerts strong linear selection on both overall CHC abundance and body size in males, while female mate choice exerts a mixture of linear and nonlinear selection, targeting not just the overall amount of CHCs expressed but the relative abundance of specific hydrocarbons as well. We discuss the potential implications of this antagonistic selection with regard to male reproductive success. © 2016 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.

Masculine somatotype and hirsuteness as determinants of sexual attractiveness to women.

PubMed

Dixson, Alan F; Halliwell, Gayle; East, Rebecca; Wignarajah, Praveen; Anderson, Matthew J

2003-02-01

Five questionnaire studies asked women to rate the attractiveness of outline drawings of male figures that varied in somatotype, body proportions, symmetry, and in distribution of trunk hair. In Study 1, back-posed figures of mesomorphic (muscular) somatotypes were rated as most attractive, followed by average, ectomorphic (slim), and endomorphic (heavily built) figures by both British and Sri Lankan women. In Study 2, computer morphing of somatotypes to produce an intergraded series resulted in a graded response in terms of perceived attractiveness which mirrored the findings of Study 1. In Study 3, back-posed figures were manipulated in order to change waist-to-hip ratios (WHR) and waist-to-shoulder ratios (WSR). A WHR of 0.8-0.9 and a WSR of 0.6 were rated as most attractive and these effects were more pronounced when modeling mesomorphic figures. In Study 4, symmetric figures of a mesomorphic somatotype were rated as less attractive than a normal (asymmetric) version of the same man. Study 5 showed that presence of trunk hair had a marked, positive effect upon women's ratings of attractiveness for both mesomorphic and endomorphic male figures. Women also judged figures with trunk hair as being older and they consistently rated endomorphic figures as being older than mesomorphs. These results are consistent with effects of sexual selection upon visual signals that advertise health, physical prowess, age, and underlying endocrine condition in the human male.

Birth order and recalled childhood gender nonconformity in Samoan men and fa'afafine.

PubMed

Semenyna, Scott W; VanderLaan, Doug P; Vasey, Paul L

2017-04-01

Having a greater than average number of older biological brothers is a robust correlate of male androphilia (i.e., sexual attraction and arousal to adult males). Previous investigations have sought to understand whether this fraternal birth order (FBO) effect is also systematically related to recalled indicators of childhood gender nonconformity (CGN). However, these investigations have relied on data from low-fertility Western populations in which expressions of femininity in male children are routinely stigmatized and consequently, suppressed. The present study examined the FBO effect (among other sibship characteristics) and recalled indicators of CGN in Samoa, a high-fertility population, whose members are relatively tolerant of male femininity. Indeed, Samoans identify feminine androphilic males as belonging to an alternative gender category, known locally as fa'afafine. The present study compared the sibship characteristics of 231 fa'afafine and 231 opposite-sex attracted men from Samoa, as well as how these characteristics related to recalled CGN. Results replicated the well-established FBO effect for predicting male sexual orientation, with each older brother increasing the odds of being androphilic by 21%. However, no relationship was found between the number of older brothers (or other siblings) a participant had and their recalled CGN. Although fa'afafine reported significantly more CGN than Samoan men, CGN did not mediate the FBO effect, nor did the FBO effect and CGN interact to predict male sexual orientation. These findings are consistent with previous studies suggesting that the FBO effect is associated with male sexual orientation, but not childhood female-typical gender expression among androphilic males. © 2017 Wiley Periodicals, Inc.

Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

PubMed

Dötterl, Stefan; Glück, Ulrike; Jürgens, Andreas; Woodring, Joseph; Aas, Gregor

2014-01-01

In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward) than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i) to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues) in dioecious sallow, Salix caprea, ii) to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii) to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants.

Floral Reward, Advertisement and Attractiveness to Honey Bees in Dioecious Salix caprea

PubMed Central

Dötterl, Stefan; Glück, Ulrike; Jürgens, Andreas; Woodring, Joseph; Aas, Gregor

2014-01-01

In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward) than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i) to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues) in dioecious sallow, Salix caprea, ii) to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii) to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants. PMID:24676333

Sexual selection and physical attractiveness : Implications for mating dynamics.

PubMed

Gangestad, S W

1993-09-01

Sexual selection processes have received much attention in recent years, attention reflected in interest in human mate preferences. Among these mate preferences are preferences for physical attractiveness. Preferences in and of themselves, however, do not fully explain the nature of the relationships that individuals attain. A tacit negotiation process underlies relationship formation and maintenance. The notion that preferences for physical attractiveness evolved under parasite-driven "good genes" sexual selection leads to predictions about the nature of trade-offs that individuals make between mates' physical attractiveness and investment potential. These predictions and relevant data are explored, with a primary emphasis on women's preferences for men's qualities. In addition, further implications of trade-offs are examined, most notably (a) the impact of environmental variations on the nature of mating and (b) some effects of trade-offs on infidelity and male attempts to control women.

An integrative view of sexual selection in Tribolium flour beetles.

PubMed

Fedina, Tatyana Y; Lewis, Sara M

2008-05-01

Sexual selection is a major force driving the evolution of diverse reproductive traits. This evolutionary process is based on individual reproductive advantages that arise either through intrasexual competition or through intersexual choice and conflict. While classical studies of sexual selection focused mainly on differences in male mating success, more recent work has focused on the differences in paternity share that may arise through sperm competition or cryptic female choice whenever females mate with multiple males. Thus, an integrative view of sexual selection needs to encompass processes that occur not only before copulation (pre-mating), but also during copulation (peri-mating), as well as after copulation (post-mating), all of which can generate differences in reproductive success. By encompassing mechanisms of sexual selection across all of these sequential reproductive stages this review takes an integrative approach to sexual selection in Tribolium flour beetles (Coleoptera: Tenebrionidae), a particularly well-studied and economically important model organism. Tribolium flour beetles colonize patchily distributed grain stores, and juvenile and adult stages share the same food resources. Adults are highly promiscuous and female reproduction is distributed across an adult lifespan lasting approximately 1 year. While Tribolium males produce an aggregation pheromone that attracts both sexes, there appears to be little pre-mating discrimination among potential mates by either sex. However, recent work has revealed several peri-mating and post-mating mechanisms that determine how offspring paternity is apportioned among a female's mates. During mating, Tribolium females reject spermatophore transfer and limit sperm numbers transferred by males with low phenotypic quality. Although there is some conflicting evidence, male copulatory leg-rubbing appears to be associated with overcoming female resistance to insemination and does not influence a male's subsequent paternity share. Evidence suggests that Tribolium beetles have several possible post-mating mechanisms that they may use to bias paternity. Male sperm precedence has been extensively studied in Tribolium spp. and the related Tenebrio molitor, and several factors influencing male paternity share among a female's progeny have been identified. These include oviposition time, inter-mating interval, male strain/genotype, the mating regimen of a male's mother, male starvation, and tapeworm infection. Females exert muscular control over sperm storage, although there is no evidence to date that females use this to differentiate among mates. Females could also influence offspring paternity by re-mating with additional males, and T. castaneum females more readily accept spermatophores when they are re-mating with more attractive males. Additional work is needed to examine the possible roles played by both male and female accessory gland products in determining male paternity share. Sexual selection during pre-mating episodes may be reinforced or counteracted by peri- and post-copulatory selection, and antagonistic coevolution between the sexes may be played out across reproductive stages. In Tribolium, males' olfactory attractiveness is positively correlated with both insemination success and paternity share, suggesting consistent selection across different reproductive stages. Similar studies across sequential reproductive stages are needed in other taxa to provide a more integrative view of sexual selection.

Gender-Specificity in Viewing Time Among Heterosexual Women.

PubMed

Xu, Yin; Rahman, Qazi; Zheng, Yong

2017-07-01

Measures of sexual interest tend to be more gender-specific in heterosexual men than in heterosexual women. Cognitive measures, such as viewing time to attractive stimuli, may also show similar patterns of gender-specificity or nonspecificity among men and women and thus serve as useful adjuncts to more direct measures of sexual interest. The objectives of the present research were to determine the extent of gender-specificity in women's viewing times for female pictures (varying in their perceived physical attractiveness) and explore the influence of social comparison of physical appearance on these patterns of responses. In Study 1, we recorded only women's viewing times for pictures of both genders, measured self-reported menstrual cycle phase, and manipulated the waist-to-hip ratio of the women in the female pictures. In Study 2, we recorded women's and men's viewing times, self-reported sexual attraction to pictures of males and females, and physical appearance social comparison. Study 1 found that heterosexual women's viewing time toward female pictures was not associated with manipulation of the perceived attractiveness of those pictures. Study 2 found that heterosexual men were more gender-specific than heterosexual women in their viewing time patterns. We also found that reported sexual attraction and physical appearance social comparison were associated with heterosexual women's viewing times for female pictures, while heterosexual men's viewing times were associated with sexual attraction only. Our results are discussed in relation to the utility of viewing time as an indicator of visual attention toward attractive or sexually appealing visual stimuli.

Sites of release of Putative Sex Pheromone and Sexual Behaviour in Female Carcinus maenas(Crustacea: Decapoda)

NASA Astrophysics Data System (ADS)

Bamber, S. D.; Naylor, E.

1997-02-01

Pre-moult female Carcinus maenasurine was confirmed as a source of putative sex pheromone. The sexual and temporal specificity of bioactivity in pre-moult female urine was demonstrated when urine samples taken from inter-moult and pre-moult male crabs, and inter-moult females, failed to generate a sexual response from receptive males. Detection sensitivity of male crabs to pre-moult female urine was established at a dilution factor of 1 μl of urine in 10 ml of seawater. Experimental blockage of the site of urine release (the antennal gland opercula) failed to diminish the chemical attractiveness of pre-moult female crabs to test males, implicating at least one further site of putative pheromone release. Observations of female sexual behaviour demonstrated an active role by pre-moult and post-moult female crabs when introduced to male crabs whose locomotor movement had been temporarily restricted.

Associations between body morphology, mating success and mate preferences among Slovak males and females.

PubMed

Prokop, Pavol; Fedor, Peter

2013-01-01

Human body morphology is thought to be correlated with sexual behaviour and sociosexuality (defined as an increased willingness to engage in sex without commitment) influences the perception of certain cues of physical attractiveness. Based on a sample of Slovak university students, we investigated relationships between 1) male and female mating success and reported body morphology (body mass index, BMI and waist-to-hip ratio, WHR) and 2) mate preference characteristics and mating success. Both males and females reported a similar number of long-term sexual partners and frequency of engaging in extra-pair copulation (EPC). The mating success of both sexes was positively mediated by self-perceived attractiveness. However, female BMI was inversely associated with mating success whereas increasing BMI was positively associated with male mating success (the total number of lifetime sexual partners) as well as with the likelihood of engaging in EPC. Unrestricted sociosexuality positively correlated with direct and indirect benefits from mating and negatively with the religious/political background of a potential mate and with the desire for a home/ children. These results confirm the hypothesis that human body morphology is associated with sexual behaviour and that cues of direct/indirect benefits in a potential mate positively correlate with sociosexuality.

Pollination: sexual mimicry abounds.

PubMed

Schiestl, Florian P

2010-12-07

Why do plants mimic female insects to attract males for pollination? A new study gives insights into the advantages of sexual mimicry and documents this pollination system for the first time outside the orchid family, in a South African daisy. Copyright © 2010 Elsevier Ltd. All rights reserved.

Sexy males and choosy females on exploded leks: correlates of male attractiveness in the Little Bustard.

PubMed

Jiguet, Frédéric; Bretagnolle, Vincent

2014-03-01

In their choice of mates, females may use alternative tactics, including a comparative assessment of males in a population, using one or several relative preference criteria. Traits involved in female choice should presumably be variable between, but not within males, thus potentially providing reliable cues of male identity and quality for prospecting females. In lekking species, sexual selection is usually intense, and females can freely choose mates. Studying the Little Bustard Tetrax tetrax, a bird with an exploded lek mating system, we first identified male phenotypic traits that showed higher among, than within variation (plumage pattern, display rates and call structure). Among those and other traits (ornaments and their symmetry, body condition, lek spatial organization and territory quality), we identified phenotypic traits that correlated with male attractiveness toward females. At least four phenotypic male traits were correlated with female attraction, i.e. body condition, lek attendance, ornamental symmetry and display rates. Traits related to the initial female attraction on male territory seem to differ from traits related to the decision of females to stay in the territory of attractive males. Copyright © 2014 Elsevier B.V. All rights reserved.

No Evidence for Heritability of Male Mating Latency or Copulation Duration across Social Environments in Drosophila melanogaster

PubMed Central

Taylor, Michelle L.; Evans, Jonathan P.; Garcia-Gonzalez, Francisco

2013-01-01

A key assumption underpinning major models of sexual selection is the expectation that male sexual attractiveness is heritable. Surprisingly, however, empirical tests of this assumption are relatively scarce. Here we use a paternal full-sib/half-sib breeding design to examine genetic and environmental variation in male mating latency (a proxy for sexual attractiveness) and copulation duration in a natural population of Drosophila melanogaster. As our experimental design also involved the manipulation of the social environment within each full-sibling family, we were able to further test for the presence of genotype-by-environment interactions (GEIs) in these traits, which have the potential to compromise mate choice for genetic benefits. Our experimental manipulation of the social environment revealed plastic expression of both traits; males exposed to a rival male during the sensitive period of adult sexual maturation exhibited shorter mating latencies and longer copulation durations than those who matured in isolation. However, we found no evidence for GEIs, and no significant additive genetic variation underlying these traits in either environment. These results undermine the notion that the evolution of female choice rests on covariance between female preference and male displays, an expectation that underpins indirect benefit models such as the good genes and sexy sons hypotheses. However, our results may also indicate depletion of genetic variance in these traits in the natural population studied, thus supporting the expectation that traits closely aligned with reproductive fitness can exhibit low levels of additive genetic variance. PMID:24155948

How Song Experience Affects Female Mate-Choice, Male Song, and Monoaminergic Activity in the Auditory Telencephalon in Lincoln's Sparrows.

PubMed

Sockman, Keith W; Lyons, Susan M

2017-10-01

A sexual signal can indicate not only the signaler's attractiveness as a potential mate but also the signaler's competitiveness relative to rivals. As the attractiveness or competitiveness of the prevailing signaling environment increases, individuals prospecting for mates should change their choice threshold, whereas competing individuals should shift resources toward elevating their own competitiveness. Previous studies show that experimental elevations of song competition increase male competitive behavior in Lincoln's sparrows (Melospiza lincolnii) and European starlings (Sturnus vulgaris). Through a series of experimental manipulations using laboratory-housed Lincoln's sparrows, we have also discovered that females change the strength of their song preferences depending on the attractiveness of the song environment to which they have recently been exposed; compared to a less-attractive environment, a highly-attractive environment elevates the threshold for releasing phonotaxis behavior toward male song. These behavioral adjustments are associated with changes in forebrain monoaminergic activity that are triggered by experimental manipulations of the quality of the song environment. Findings from these studies suggest possible neural mechanisms for the regulation of adaptive behavioral plasticity associated with dynamic sexual signaling environments. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Genetic Architecture of Sexual Selection: QTL Mapping of Male Song and Female Receiver Traits in an Acoustic Moth

PubMed Central

Limousin, Denis; Streiff, Réjane; Courtois, Brigitte; Dupuy, Virginie; Alem, Sylvain; Greenfield, Michael D.

2012-01-01

Models of indirect (genetic) benefits sexual selection predict linkage disequilibria between genes that influence male traits and female preferences, owing to non-random mate choice or physical linkage. Such linkage disequilibria can accelerate the evolution of traits and preferences to exaggerated levels. Both theory and recent empirical findings on species recognition suggest that such linkage disequilibria may result from physical linkage or pleiotropy, but very little work has addressed this possibility within the context of sexual selection. We studied the genetic architecture of sexually selected traits by analyzing signals and preferences in an acoustic moth, Achroia grisella, in which males attract females with a train of ultrasound pulses and females prefer loud songs and a fast pulse rhythm. Both male signal characters and female preferences are repeatable and heritable traits. Moreover, female choice is based largely on male song, while males do not appear to provide direct benefits at mating. Thus, some genetic correlation between song and preference traits is expected. We employed a standard crossing design between inbred lines and used AFLP markers to build a linkage map for this species and locate quantitative trait loci (QTL) that influence male song and female preference. Our analyses mostly revealed QTLs of moderate strength that influence various male signal and female receiver traits, but one QTL was found that exerts a major influence on the pulse-pair rate of male song, a critical trait in female attraction. However, we found no evidence of specific co-localization of QTLs influencing male signal and female receiver traits on the same linkage groups. This finding suggests that the sexual selection process would proceed at a modest rate in A. grisella and that evolution toward exaggerated character states may be tempered. We suggest that this equilibrium state may be more the norm than the exception among animal species. PMID:22957082

Benevolent sexist ideology attributed to an abusive partner decreases women's active coping responses to acts of sexual violence.

PubMed

Durán, Mercedes; Moya, Miguel; Megías, Jesús L

2014-05-01

This article describes three studies in which we explored the influence of the sexist ideology attributed to the perpetrator on women's responses to hypothetical acts of sexual assault perpetrated by male intimate partners. In Study 1 (n = 83), college women read three sexual assault scenarios in the context of an intimate relationship. The male partner's sexist ideology (benevolent, hostile, or control) was manipulated within participants. Women showed less active responses when the partner had been described as a benevolent sexist man. This effect was replicated in Study 2 (n = 103), which showed a relationship between women's less active responses and the belief that benevolent sexist men are very attracted to and interested in their partners. Study 3 (n = 130) demonstrated experimentally that women's responses are less active when they are exposed to information that indicates that the perpetrator is both high in benevolent sexism and highly attracted to his victim than when the latter information is not provided. Results suggest that sexist ideology and particularly benevolent sexism-attributed to the perpetrator in this case-is highly important in women's reactions to acts of sexual violence perpetrated by male intimate partners.

A relationship between attractiveness and performance in professional cyclists

PubMed Central

Postma, Erik

2014-01-01

Females often prefer to mate with high quality males, and one aspect of quality is physical performance. Although a preference for physically fitter males is therefore predicted, the relationship between attractiveness and performance has rarely been quantified. Here, I test for such a relationship in humans and ask whether variation in (endurance) performance is associated with variation in facial attractiveness within elite professional cyclists that finished the 2012 Tour de France. I show that riders that performed better were more attractive, and that this preference was strongest in women not using a hormonal contraceptive. Thereby, I show that, within this preselected but relatively homogeneous sample of the male population, facial attractiveness signals endurance performance. Provided that there is a relationship between performance-mediated attractiveness and reproductive success, this suggests that human endurance capacity has been subject to sexual selection in our evolutionary past. PMID:24501269

Male vocal competition is dynamic and strongly affected by social contexts in music frogs.

PubMed

Fang, Guangzhan; Jiang, Fan; Yang, Ping; Cui, Jianguo; Brauth, Steven E; Tang, Yezhong

2014-03-01

Male-male vocal competition in anuran species is critical for mating success; however, it is also highly time-consuming, energetically demanding and likely to increase predation risks. Thus, we hypothesized that changes in the social context would cause male vocal competition to change in real time in order to minimize the costs and maximize the benefits of competition. To test this hypothesis, we assessed the effect of repeating playbacks of either white noise (WN) or male advertisement calls on male call production in the Emei music frog (Babina daunchina), a species in which males build mud-retuse burrows and call from within these nests. Previous studies have shown that calls produced from inside burrows are highly sexually attractive (HSA) to females while those produced outside nests are of low sexual attractiveness (LSA). Results showed that most subjects called responsively after the end of WN playbacks but before the onset of conspecific call stimuli although call numbers were similar, indicating that while males adjusted competitive patterns according to the biological significance of signals, their competitive motivation did not change. Furthermore, these data indicate that the frogs had evolved the ability of interval timing. Moreover, when the inter-stimulus interval (ISI) between playbacks was varied, the subjects preferentially competed with HSA calls when the ISI was short (<4 s) but responded equally to HSA and LSA calls if the ISI was long (≥4 s), suggesting that males allocate competitive efforts depending on both the perceived sexual attractiveness of rivals and the time available for calling. Notably, approximately two-thirds of male calls occurred in response to HSA calls, a preference rate comparable to that previously found for females in phonotaxis experiments and consistent with the idea that the mechanisms underlying both the male's competitive responses to rivals and the female's preferences toward potential mates coevolved under the same selective pressure.

Geographic Variation in Sexual Attraction of Spodoptera frugiperda Corn- and Rice-Strain Males to Pheromone Lures

PubMed Central

Unbehend, Melanie; Hänniger, Sabine; Vásquez, Gissella M.; Juárez, María Laura; Reisig, Dominic; McNeil, Jeremy N.; Meagher, Robert L.; Jenkins, David A.; Heckel, David G.; Groot, Astrid T.

2014-01-01

The corn- and rice-strains of Spodoptera frugiperda exhibit several genetic and behavioral differences and appear to be undergoing ecological speciation in sympatry. Previous studies reported conflicting results when investigating male attraction to pheromone lures in different regions, but this could have been due to inter-strain and/or geographic differences. Therefore, we investigated whether corn- and rice-strain males differed in their response to different synthetic pheromone blends in different regions in North America, the Caribbean and South America. All trapped males were strain-typed by two strain-specific mitochondrial DNA markers. In the first experiment, we found a nearly similar response of corn- and rice-strain males to two different 4-component blends, resembling the corn- and rice-strain female blend we previously described from females in Florida. This response showed some geographic variation in fields in Canada, North Carolina, Florida, Puerto Rico, and South America (Peru, Argentina). In dose-response experiments with the critical secondary sex pheromone component (Z)-7-dodecenyl acetate (Z7-12:OAc), we found some strain-specific differences in male attraction. While the response to Z7-12:OAc varied geographically in the corn-strain, rice-strain males showed almost no variation. We also found that the minor compound (Z)-11-hexadecenyl acetate (Z11-16:OAc) did not increase attraction of both strains in Florida and of corn-strain males in Peru. In a fourth experiment, where we added the stereo-isomer of the critical sex pheromone component, (E)-7-dodecenyl acetate, to the major pheromone component (Z)-9-tetradecenyl acetate (Z9-14:OAc), we found that this compound was attractive to males in North Carolina, but not to males in Peru. Overall, our results suggest that both strains show rather geographic than strain-specific differences in their response to pheromone lures, and that regional sexual communication differences might cause geographic differentiation between populations. PMID:24586634

Is homophobia associated with an implicit same-sex attraction?

PubMed

Macinnis, Cara C; Hodson, Gordon

2013-01-01

Some theorists propose that homophobia stems from underlying same-sex attraction. A few studies have tested this hypothesis, yet without a clear measure of implicit sexual attraction, producing mixed results. For the first time, we test this attraction-based account of homophobia among both men and women using an implicit measure of sexual attraction. No evidence of an attraction-based account of homophobia emerged. Instead, implicit same-sex attraction was related to positive evaluations of gay men and lesbians among female participants. Even in targeted analyses examining the relation between implicit same-sex attraction and homosexual evaluations among only those theoretically most likely to demonstrate an attraction-based homophobic effect, implicit same-sex attraction was not associated with evaluations of homosexuals or was associated with more positive evaluations of homosexuals. In addition, explicit same-sex attraction was related to positive evaluations of gay men and lesbians for male participants. These results are more in keeping with the attitude-similarity effect (i.e., people like, rather than dislike, similar others).

Is male rhesus macaque red color ornamentation attractive to females?

PubMed Central

Dubuc, Constance; Allen, William L.; Maestripieri, Dario; Higham, James P.

2014-01-01

Male sexually-selected traits can evolve through different mechanisms: conspicuous and colorful ornaments usually evolve through inter-sexual selection, while weapons usually evolve through intra-sexual selection. Male ornaments are rare among mammals in comparison to birds, leading to the notion that female mate choice generally plays little role in trait evolution in this taxon. Supporting this view, when ornaments are present in mammals they typically indicate social status and are products of male-male competition. This general mammalian pattern, however, may not apply to rhesus macaques (Macaca mulatta). Males of this species display conspicuous skin coloration, but this expression is not correlated to dominance rank, and is therefore unlikely to have evolved due to male-male competition. Here, we investigate whether male color expression influences female proceptivity towards males in the Cayo Santiago free-ranging rhesus macaque population. We collected face images of 24 adult males varying in dominance rank and age at the peak of the mating season, and modeled these to rhesus macaque visual perception. We also recorded female socio-sexual behaviors towards these males. Results show that dark red males received more sexual solicitations, by more females, than pale pink ones. Together with previous results, our study suggests that male color ornaments are more likely to be a product of inter- rather than intra-sexual selection. This may especially be the case in rhesus macaques due to the particular characteristics of male-male competition in this species. PMID:25246728

Sexual Signaling and Immune Function in the Black Field Cricket Teleogryllus commodus

PubMed Central

Drayton, Jean M.; Hall, Matthew D.; Hunt, John; Jennions, Michael D.

2012-01-01

The immunocompetence handicap hypothesis predicts that male sexual trait expression should be positively correlated with immunocompetence. Here we investigate if immune function in the cricket, Teleogryllus commodus, is related to specific individual components of male sexual signals, as well as to certain multivariate combinations of these components that females most strongly prefer. Male T. commodus produce both advertisement and courtship calls prior to mating. We measured fine-scale structural parameters of both call types and also recorded nightly advertisement calling effort. We then measured two standard indices of immune function: lysozyme-like activity of the haemolymph and haemocyte counts. We found a weak, positive relationship between advertisement calling effort and lysozyme-like activity. There was, however, little evidence that individual structural call components or the net multivariate attractiveness of either call type signalled immune function. The relationships between immunity and sexual signaling did not differ between inbred and outbred males. Our data suggest that it is unlikely that females assess overall male immune function using male calls. PMID:22808047

Birth order and avuncular tendencies in Samoan men and fa'afafine.

PubMed

Vanderlaan, Doug P; Vasey, Paul L

2013-04-01

Androphilia refers to sexual attraction and arousal to males whereas gynephilia refers to sexual attraction and arousal to females. In Samoa, transgendered androphilic males are known locally as fa'afafine. Previous research has shown that, compared to Samoan gynephilic men, fa'afafine report greater willingness to invest time and money toward nieces and nephews (i.e., greater avuncular tendencies) and also have greater numbers of older brothers and older sisters. The present study examined whether the Samoan male sexual orientation difference in avuncular tendencies could be accounted for by these parallel differences in numbers of older brothers and older sisters. The sample included 204 fa'afafine and 272 Samoan gynephilic men from our Samoan data archive for whom we had concurrent information on (1) a measure of willingness to invest time and money in nieces and nephews (i.e., avuncular tendencies) and (2) numbers of older and younger biological brothers and sisters. Among fa'afafine, but not Samoan gynephilic men, number of older brothers and number of older sisters were both significantly positively associated with avuncular tendencies. When controlling for number of older brothers, the magnitude of the male sexual orientation difference in avuncular tendencies was lowered, but remained statistically significant. In contrast, when controlling for number of older sisters, the male sexual orientation difference in avuncular tendencies ceased to exist. Discussion detailed how these findings help hone in on the proximate basis of elevated avuncular tendencies among fa'afafine. In addition, discussion focused on how particular evolutionary and cultural factors might relate to the avuncularity of fa'afafine.

Attractiveness of the underling: an automatic power --> sex association and its consequences for sexual harassment and aggression.

PubMed

Bargh, J A; Raymond, P; Pryor, J B; Strack, F

1995-05-01

One characteristic of men who sexually harass is that they are not aware that their actions are inappropriate or a misuse of their power (L. F. Fitzgerald, 1993a). We investigated the existence and automaticity of a mental association between the concepts of power and sex, and its consequences for sexual harassment tendencies. Using a subliminal priming paradigm, Experiment 1 demonstrated an automatic link between power and sex, and only for men high in the likelihood to sexually harass or aggress. In Experiment 2, male participants were unobtrusively primed with either power-related or neutral stimuli. For men likely to sexually aggress, but not other participants, attraction ratings of a female confederate were significantly higher in the power priming than the neutral priming condition.

Post-copulatory sexual selection and sexual conflict in the evolution of male pregnancy.

PubMed

Paczolt, Kimberly A; Jones, Adam G

2010-03-18

Male pregnancy in seahorses, pipefishes and sea dragons (family Syngnathidae) represents a striking reproductive adaptation that has shaped the evolution of behaviour and morphology in this group of fishes. In many syngnathid species, males brood their offspring in a specialized pouch, which presumably evolved to facilitate male parental care. However, an unexplored possibility is that brood pouch evolution was partly shaped by parent-offspring or sexual conflict, processes that would result in trade-offs between current and future pregnancies. Here we report a controlled breeding experiment using the sexually dimorphic Gulf pipefish, Syngnathus scovelli, to test for post-copulatory sexual selection within broods and for trade-offs between successive male pregnancies as functions of female attractiveness. Offspring survivorship within a pregnancy was affected by the size of a male's mate, the number of eggs transferred and the male's sexual responsiveness. Significantly, we also found that embryo survivorship in a current pregnancy was negatively related to survivorship in the prior pregnancy, clearly demonstrating fitness trade-offs between broods. Overall, our data indicate that post-copulatory sexual selection and sexual conflict occur in Gulf pipefishes. The conflict seems to be mediated by a strategy of cryptic choice in which males increase rates of offspring abortion in pregnancies from unattractive mothers to retain resources for future reproductive opportunities. Hence, the male brood pouch of syngnathid fishes, which nurtures offspring, also seems to have an important role as an arbiter of conflict between the sexes.

The Association Between Supportive High School Environments and Depressive Symptoms and Suicidality Among Sexual Minority Students.

PubMed

Denny, Simon; Lucassen, Mathijs F G; Stuart, Jaimee; Fleming, Theresa; Bullen, Pat; Peiris-John, Roshini; Rossen, Fiona V; Utter, Jennifer

2016-01-01

The purpose of this study was to determine if sexual minority students in supportive school environments experienced fewer depressive symptoms and lower rates of suicide ideation, plans and attempts ("suicidality") than sexual minority students in less supportive school environments. In 2007, a nationally representative sample (N = 9,056) of students from 96 high schools in New Zealand used Internet tablets to complete a health and well-being survey that included questions on sexual attractions, depressive symptoms, and suicidality. Students reported their experience of supportive environments at school and gay, lesbian, bisexual, and transgender (GLBT) bullying, and these items were aggregated to the school level. Teachers (n = 2,901) from participating schools completed questionnaires on aspects of school climate, which included how supportive their schools were toward sexual minority students. Multilevel models were used to estimate school effects on depressive symptoms and suicidality controlling for background characteristics of students. Sexual minority students were more likely to report higher levels of depressive symptoms and suicidality than their opposite-sex attracted peers (p < .001). Teacher reports of more supportive school environments for GLBT students were associated with fewer depressive symptoms among male sexual minority students (p = .006) but not for female sexual minority students (p = .09). Likewise in schools where students reported a more supportive school environment, male sexual minority students reported fewer depressive symptoms (p = .006) and less suicidality (p < .001) than in schools where students reported less favorable school climates. These results suggest that schools play an important role in providing safe and supportive environments for male sexual minority students.

Alcoholism in cockchafers: orientation of male Melolontha melolontha towards green leaf alcohols

NASA Astrophysics Data System (ADS)

Reinecke, Andreas; Ruther, Joachim; Tolasch, Till; Francke, Wittko; Hilker, Monika

2002-03-01

Chemical orientation of the European cockchafer, Melolontha melolontha L., a serious pest in agriculture and horticulture, was investigated by field tests and electrophysiological experiments using plant volatiles. In total, 16 typical plant volatiles were shown to elicit electrophysiological responses in male cockchafers. Funnel trap field bioassays revealed that green leaf alcohols (i.e. (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol and 1-hexanol) attracted males, whereas the corresponding aldehydes and acetates were behaviourally inactive. Furthermore, male cockchafers were attracted by volatiles from mechanically damaged leaves of Fagus sylvatica L., Quercus robur L. and Carpinus betulus L. However, volatiles emitted by damaged leaves of F. sylvatica attracted significantly more males than those from the other host plants. Odour from intact F. sylvatica leaves was not attractive to M. melolontha males. Females were not attracted by any of the tested volatile sources. The results suggest that plant volatiles play a similar role as a sexual kairomone in mate finding of M. melolontha, as has been shown for the forest cockchafer, Melolontha hippocastani F. Nevertheless, both species show remarkable differences in their reaction to green leaf alcohols.

Male sexual strategies modify ratings of female models with specific waist-to-hip ratios.

PubMed

Brase, Gary L; Walker, Gary

2004-06-01

Female waist-to-hip ratio (WHR) has generally been an important general predictor of ratings of physical attractiveness and related characteristics. Individual differences in ratings do exist, however, and may be related to differences in the reproductive tactics of the male raters such as pursuit of short-term or long-term relationships and adjustments based on perceptions of one's own quality as a mate. Forty males, categorized according to sociosexual orientation and physical qualities (WHR, Body Mass Index, and self-rated desirability), rated female models on both attractiveness and likelihood they would approach them. Sociosexually restricted males were less likely to approach females rated as most attractive (with 0.68-0.72 WHR), as compared with unrestricted males. Males with lower scores in terms of physical qualities gave ratings indicating more favorable evaluations of female models with lower WHR. The results indicate that attractiveness and willingness to approach are overlapping but distinguishable constructs, both of which are influenced by variations in characteristics of the raters.

Assessing the Relationship Between Sexual Concordance, Sexual Attractions, and Sexual Identity in Women.

PubMed

Suschinsky, Kelly D; Dawson, Samantha J; Chivers, Meredith L

2017-01-01

On average, there is a gender difference in sexual concordance, with men exhibiting greater agreement between genital and self-reported sexual arousal, relative to women. Much less is known about the substantial variation in women's sexual concordance; women's genital and self-reported sexual responses may correlate strongly and positively, not at all, or even strongly negatively. The within-gender variation in sexual concordance suggests that individual differences may be related to sexual concordance. We examined whether sexual concordance varies as a function of sexual orientation (based on self-reported sexual attractions and sexual identity labels) in a sample (N = 76) that included exclusively androphilic, predominantly androphilic, ambiphilic, and predominantly/exclusively gynephilic women. Participants viewed sexual and nonsexual stimuli that varied by actor gender while their vaginal vasocongestion and subjective sexual responses were measured. Women's sexual concordance varied as a function of their sexual attractions; women with any degree of gynephilia exhibited higher sexual concordance than exclusively androphilic women across a variety of sexual concordance measures, and these effects were demonstrated using correlation and multi-level modeling analyses. Only sexual concordance based on overall feelings of arousal varied by sexual identity, with heterosexual women exhibiting the lowest sexual concordance. Stimulus gender significantly influenced sexual concordance for most groups of women: Ambiphilic and predominantly/exclusively gynephilic women exhibited greater sexual concordance to female stimuli and exclusively androphilic women exhibited greater sexual concordance to male stimuli. These findings suggest that sexual orientation (particularly one's degree of gynephilia) may explain some of the within-gender variation seen in women's sexual concordance.

Physical strength and dance attractiveness: Further evidence for an association in men, but not in women.

PubMed

Weege, Bettina; Pham, Michael N; Shackelford, Todd K; Fink, Bernhard

2015-01-01

Physical strength provides information about male quality and can be assessed from facial and body morphology. Research on perception of dance movements indicates that body movement also provides information about male physical strength. These relationships have not been investigated for women. We investigated relationships of handgrip strength (HGS) and dance attractiveness perception in 75 men and 84 women. We identified positive relationships between HGS and opposite-sex assessments of dance attractiveness for men but not women. The replication of previous research investigating relationships between dance attractiveness and physical strength in men corroborates the hypothesis that dance movements provide information about male quality. We argue that these relationships are interpretable in contexts of inter- and intra-sexual selection. © 2015 Wiley Periodicals, Inc.

Maternal investment in the swordtail fish Xiphophorus multilineatus: support for the differential allocation hypothesis.

PubMed

Rios-Cardenas, Oscar; Brewer, Jason; Morris, Molly R

2013-01-01

The differential allocation hypothesis predicts that reproductive investment will be influenced by mate attractiveness, given a cost to reproduction and a tradeoff between current and future reproduction. We tested the differential allocation hypothesis in the swordtail fish Xiphophorus multilineatus, where males have genetically influenced (patroclinous inheritance) alternative mating tactics (ARTs) maintained by a tradeoff between being more attractive to females (mature later as larger courting males) and a higher probability of reaching sexual maturity (mature earlier as smaller sneaker males). Males in X. multilineatus do not provide parental care or other resources to the offspring. Allelic variation and copy number of the Mc4R gene on the Y-chromosome influences the size differences between males, however there is no variation in this gene on the X-chromosome. Therefore, to determine if mothers invested more in offspring of the larger courter males, we examined age to sexual maturity for daughters. We confirmed a tradeoff between number of offspring and female offspring's age to sexual maturity, corroborating that there is a cost to reproduction. In addition, the ART of their fathers significantly influenced the age at which daughters reached sexual maturity, suggesting increased maternal investment to daughters of courter males. The differential allocation we detected was influenced by how long the wild-caught mother had been in the laboratory, as there was a brood order by father genotype (ART) interaction. These results suggest that females can adjust their reproductive investment strategy, and that differential allocation is context specific. We hypothesize that one of two aspects of laboratory conditions produced this shift: increased female condition due to higher quality diet, and/or assessment of future mating opportunities due to isolation from males.

Maternal Investment in the Swordtail Fish Xiphophorus multilineatus: Support for the Differential Allocation Hypothesis

PubMed Central

Rios-Cardenas, Oscar; Brewer, Jason; Morris, Molly R.

2013-01-01

The differential allocation hypothesis predicts that reproductive investment will be influenced by mate attractiveness, given a cost to reproduction and a tradeoff between current and future reproduction. We tested the differential allocation hypothesis in the swordtail fish Xiphophorus multilineatus, where males have genetically influenced (patroclinous inheritance) alternative mating tactics (ARTs) maintained by a tradeoff between being more attractive to females (mature later as larger courting males) and a higher probability of reaching sexual maturity (mature earlier as smaller sneaker males). Males in X. multilineatus do not provide parental care or other resources to the offspring. Allelic variation and copy number of the Mc4R gene on the Y-chromosome influences the size differences between males, however there is no variation in this gene on the X-chromosome. Therefore, to determine if mothers invested more in offspring of the larger courter males, we examined age to sexual maturity for daughters. We confirmed a tradeoff between number of offspring and female offspring’s age to sexual maturity, corroborating that there is a cost to reproduction. In addition, the ART of their fathers significantly influenced the age at which daughters reached sexual maturity, suggesting increased maternal investment to daughters of courter males. The differential allocation we detected was influenced by how long the wild-caught mother had been in the laboratory, as there was a brood order by father genotype (ART) interaction. These results suggest that females can adjust their reproductive investment strategy, and that differential allocation is context specific. We hypothesize that one of two aspects of laboratory conditions produced this shift: increased female condition due to higher quality diet, and/or assessment of future mating opportunities due to isolation from males. PMID:24349348

Silk wrapping of nuptial gifts as visual signal for female attraction in a crepuscular spider

NASA Astrophysics Data System (ADS)

Trillo, Mariana C.; Melo-González, Valentina; Albo, Maria J.

2014-02-01

An extensive diversity of nuptial gifts is known in invertebrates, but prey wrapped in silk is a unique type of gift present in few insects and spiders. Females from spider species prefer males offering a gift accepting more and longer matings than when males offered no gift. Silk wrapping of the gift is not essential to obtain a mating, but appears to increase the chance of a mating evidencing a particularly intriguing function of this trait. Consequently, as other secondary sexual traits, silk wrapping may be an important trait under sexual selection, if it is used by females as a signal providing information on male quality. We aimed to understand whether the white color of wrapped gifts is used as visual signal during courtship in the spider Paratrechalea ornata. We studied if a patch of white paint on the males' chelicerae is attractive to females by exposing females to males: with their chelicerae painted white; without paint; and with the sternum painted white (paint control). Females contacted males with white chelicerae more often and those males obtained higher mating success than other males. Thereafter, we explored whether silk wrapping is a condition-dependent trait and drives female visual attraction. We exposed good and poor condition males, carrying a prey, to the female silk. Males in poor condition added less silk to the prey than males in good condition, indicating that gift wrapping is an indicator of male quality and may be used by females to acquire information of the potential mate.

Sexual orientation of female-to-male transsexuals: a comparison of homosexual and nonhomosexual types.

PubMed

Chivers, M L; Bailey, J M

2000-06-01

Homosexual and nonhomosexual (relative to genetic sex) female-to-male transsexuals (FTMs) were compared on a number of theoretically or empirically derived variables. Compared to nonhomosexual FTMs, homosexual FTMs reported greater childhood gender nonconformity, preferred more feminine partners, experienced greater sexual rather than emotional jealousy, were more sexually assertive, had more sexual partners, had a greater desire for phalloplasty, and had more interest in visual sexual stimuli. Homosexual and nonhomosexual FTMs did not differ in their overall desire for masculinizing body modifications, adult gender identity, or importance of partner social status, attractiveness, or youth. These findings indicate that FTMs are not a homogeneous group and vary in ways that may be useful in understanding the relation between sexual orientation and gender identity.

Sociosexual attitudes and dyadic sexual desire independently predict women's preferences for male vocal masculinity.

PubMed

O'Connor, Jillian J M; Jones, Benedict C; Fraccaro, Paul J; Tigue, Cara C; Pisanski, Katarzyna; Feinberg, David R

2014-10-01

Research suggests that the desire to behave sexually with a partner (dyadic sexual desire) may reflect desire for intimacy whereas solitary sexual desire may reflect pleasure seeking motivations more generally. Because direct reproductive success can only be increased with a sexual partner, we tested whether dyadic sexual desire was a better predictor of women's preferences for lower pitched men's voices (a marker of relatively high reproductive success) than was solitary sexual desire. In Study 1, women (N = 95) with higher dyadic sexual desire scores on the Sexual Desire Inventory-2 preferred masculinized male voices more than did women with lower dyadic sexual desire scores. We did not find a significant relationship between women's vocal masculinity preferences and their solitary sexual desire scores. In Study 2, we tested whether the relationship between voice preferences and dyadic sexual desire scores was related to differences in sociosexual orientation. Women (N = 80) with more positive attitudes towards uncommitted sex had stronger vocal masculinity preferences regardless of whether men's attractiveness was judged for short-term or long-term relationships. Independent of the effect of sociosexual attitudes, dyadic sexual desire positively predicted women's masculinity preferences when assessing men's attractiveness for short-term but not long-term relationships. These effects were independent of women's own relationship status and hormonal contraceptive use. Our results provide further evidence that women's mate preferences may independently reflect individual differences in both sexual desire and openness to short-term relationships, potentially with the ultimate function of maximizing the fitness benefits of women's mate choices.

Variation in sex pheromone emission does not reflect immunocompetence but affects attractiveness of male burying beetles—a combination of laboratory and field experiments

NASA Astrophysics Data System (ADS)

Chemnitz, Johanna; Bagrii, Nadiia; Ayasse, Manfred; Steiger, Sandra

2017-08-01

Life history theory predicts a trade-off between male sexual trait expression and immunocompetence. Using burying beetles, Nicrophorus vespilloides, as a model, we investigated the relationship between male immune function, sex pheromone emission, and attractiveness under field conditions. In the first experiment, we tested whether there is a positive correlation between immune capacity, sex pheromone characteristics (quantity, relative composition, and time invested in pheromone emission), and male attractiveness. As a measurement of immune capacity, we used an individual's encapsulation ability against a novel antigen. In the second experiment, we specifically examined whether a trade-off between chemical trait expression and immune function existed. To this end, we challenged the immune system and measured the subsequent investment in sex pheromone emission and the attractiveness of the male under field conditions. We found that a male's immunocompetence was neither related to the emission of the male's sex pheromone nor to its attractiveness in the field. Furthermore, none of the immune-challenge treatments affected the subsequent investment in pheromone emission or number of females attracted. However, we showed that the same males that emitted a high quantity of their sex pheromone in the laboratory were able to attract more females in the field. Our data suggest that the chemical signal is not a reliable predictor of a male's immunocompetence but rather is a general important fitness-related trait, with a higher emission of the sex pheromone measured in the laboratory directly affecting the attractiveness of a male under field conditions.

Variation in sex pheromone emission does not reflect immunocompetence but affects attractiveness of male burying beetles-a combination of laboratory and field experiments.

PubMed

Chemnitz, Johanna; Bagrii, Nadiia; Ayasse, Manfred; Steiger, Sandra

2017-08-01

Life history theory predicts a trade-off between male sexual trait expression and immunocompetence. Using burying beetles, Nicrophorus vespilloides, as a model, we investigated the relationship between male immune function, sex pheromone emission, and attractiveness under field conditions. In the first experiment, we tested whether there is a positive correlation between immune capacity, sex pheromone characteristics (quantity, relative composition, and time invested in pheromone emission), and male attractiveness. As a measurement of immune capacity, we used an individual's encapsulation ability against a novel antigen. In the second experiment, we specifically examined whether a trade-off between chemical trait expression and immune function existed. To this end, we challenged the immune system and measured the subsequent investment in sex pheromone emission and the attractiveness of the male under field conditions. We found that a male's immunocompetence was neither related to the emission of the male's sex pheromone nor to its attractiveness in the field. Furthermore, none of the immune-challenge treatments affected the subsequent investment in pheromone emission or number of females attracted. However, we showed that the same males that emitted a high quantity of their sex pheromone in the laboratory were able to attract more females in the field. Our data suggest that the chemical signal is not a reliable predictor of a male's immunocompetence but rather is a general important fitness-related trait, with a higher emission of the sex pheromone measured in the laboratory directly affecting the attractiveness of a male under field conditions.

To each its own? Gender differences in affective, autonomic, and behavioral responses to same-sex and opposite-sex visual sexual stimuli.

PubMed

Sarlo, Michela; Buodo, Giulia

2017-03-15

A large body of research on gender differences in response to erotic stimuli has focused on genital and/or subjective sexual arousal. On the other hand, studies assessing gender differences in emotional psychophysiological responding to sexual stimuli have only employed erotic pictures of male-female couples or female/male nudes. The present study aimed at investigating differences between gynephilic men and androphilic women in emotional responding to visual sexual stimuli depicting female-male, female-female and male-male couples. Affective responses were explored in multiple response systems, including autonomic indices of emotional activation, i.e., heart rate and skin conductance, along with standardized measures of valence and arousal. Blood pressure was measured as an index of autonomic activation associated with sexual arousal, and free viewing times as an index of interest/avoidance. Overall, men showed gender-specific activation characterized by clearly appetitive reactions to the target of their sexual attraction (i.e., women), with physiological arousal discriminating female-female stimuli as the most effective sexual cues. In contrast, women's emotional activation to sexual stimuli was clearly non-specific in most of the considered variables, with the notable exception of the self-report measures. Overall, affective responses replicate patterns of gender-specific and gender-nonspecific sexual responses in gynephilic men and androphilic women. Copyright © 2017 Elsevier Inc. All rights reserved.

Femininity and Kin-Directed Altruism in Androphilic Men: A Test of an Evolutionary Developmental Model.

PubMed

VanderLaan, Doug P; Petterson, Lanna J; Vasey, Paul L

2016-04-01

Androphilia refers to sexual attraction and arousal toward males whereas gynephilia refers to sexual attraction and arousal toward females. This study tested the adaptive feminine phenotype model of the evolution of male androphilia via kin selection, which posits that the development of an evolved disposition toward elevated kin-directed altruism among androphilic males is contingent on the behavioral expression of femininity. Gynephilic men, androphilic women, and androphilic men (N = 387) completed measures of childhood and adulthood gender expression and concern for kin's well-being. Adulthood femininity correlated positively with uncle/aunt-like tendencies among androphilic men and women. Although androphilic women reported greater willingness to invest in nieces and nephews than gynephilic and androphilic men, mediation analyses indicated that adult femininity completely mediated these group differences. In addition, changes in the expression of femininity between childhood and adulthood were associated with parallel changes in concern for the well-being of kin among androphilic men. Thus, these findings suggest that femininity is key to the expression of kin-directed altruism among androphilic males and may have been important in the evolution of male androphilia.

Host plant affects the sexual attractiveness of the female white-spotted longicorn beetle, Anoplophora malasiaca.

PubMed

Yasui, Hiroe; Fujiwara-Tsujii, Nao

2016-07-14

Anoplophora malasiaca (Coleoptera: Cerambycidae) is a serious pest that destroys various landscape and crop trees in Japan. We evaluated the precopulatory responses of three different A. malasiaca populations collected from mandarin orange, willow and blueberry trees. Most of the males accepted mates from within the same host plant population as well as females from the willow and blueberry populations. However, significant number of males from the blueberry and willow populations rejected females from the mandarin orange population immediately after touching them with their antennae. Because all three of the female populations produced contact sex pheromones on their elytra, the females of the mandarin orange population were predicted to possess extra chemicals that repelled the males of the other two populations. β-Elemene was identified as a key component that was only found in mandarin orange-fed females and induced a rejection response in willow-fed males. Our results represent the first example of a female-acquired repellent against conspecific males of different host plant populations, indicating that the host plant greatly affects the female's sexual attractiveness.

Same-sex sexual attraction, behavior, and practices of Jewish men in Israel and the association with HIV prevalence

PubMed Central

Mor, Zohar; Davidovich, Udi

2016-01-01

ABSTRACT In order to efficiently direct efforts and resources required for the prevention of HIV and other sexually transmitted infection among men who have sex with men (MSM) in Israel, it is necessary to define their particular behaviors, estimate their size, and asses the HIV-burden. This cross-sectional study included a sub-sample from a random representative National study performed in Israel, which included Jewish males aged 18–44 who completed online anonymous questionnaires regarding their sexual attraction and practices, commercial sex-work, as well as condom and substances' use. Additionally, participants were asked to identify themselves as gay, bisexual, or heterosexual. National estimates regarding prevalence of risk-behaviors and HIV-infection among MSM were based on the Statistical Abstract of Israel and the National HIV Registry, respectively. Of the total sample of 997 men, 11.9% reported lifetime male sex encounters, while 4.5% and 3.7% self-identified as gay or bisexual, respectively. The estimated population of self-identified Jewish gays/bisexuals aged 18–44 in Israel was 94,176, and in Tel-Aviv 33,839. HIV prevalence among MSM was estimated at 0.7% in Israel and 1.0% in Tel-Aviv. MSM were more likely to live in Tel-Aviv, had higher levels of education, and were scored higher on several determinants of sexual risk in comparison to those attracted to women, including early sexual debut, greater number of sexual partners, ever paid/been paid for sex, sexually coerced, and substance use. In conclusion, MSM were involved in greater risk behaviors than those who only had female sex partners. Most MSM were living in Tel-Aviv and their estimated HIV prevalence was 1.0%. PMID:26883581

Same-sex sexual attraction, behavior, and practices of Jewish men in Israel and the association with HIV prevalence.

PubMed

Mor, Zohar; Davidovich, Udi

2016-01-01

In order to efficiently direct efforts and resources required for the prevention of HIV and other sexually transmitted infection among men who have sex with men (MSM) in Israel, it is necessary to define their particular behaviors, estimate their size, and asses the HIV-burden. This cross-sectional study included a sub-sample from a random representative National study performed in Israel, which included Jewish males aged 18-44 who completed online anonymous questionnaires regarding their sexual attraction and practices, commercial sex-work, as well as condom and substances' use. Additionally, participants were asked to identify themselves as gay, bisexual, or heterosexual. National estimates regarding prevalence of risk-behaviors and HIV-infection among MSM were based on the Statistical Abstract of Israel and the National HIV Registry, respectively. Of the total sample of 997 men, 11.9% reported lifetime male sex encounters, while 4.5% and 3.7% self-identified as gay or bisexual, respectively. The estimated population of self-identified Jewish gays/bisexuals aged 18-44 in Israel was 94,176, and in Tel-Aviv 33,839. HIV prevalence among MSM was estimated at 0.7% in Israel and 1.0% in Tel-Aviv. MSM were more likely to live in Tel-Aviv, had higher levels of education, and were scored higher on several determinants of sexual risk in comparison to those attracted to women, including early sexual debut, greater number of sexual partners, ever paid/been paid for sex, sexually coerced, and substance use. In conclusion, MSM were involved in greater risk behaviors than those who only had female sex partners. Most MSM were living in Tel-Aviv and their estimated HIV prevalence was 1.0%.

Sexual dimorphism in striatal dopaminergic responses promotes monogamy in social songbirds.

PubMed

Tokarev, Kirill; Hyland Bruno, Julia; Ljubičić, Iva; Kothari, Paresh J; Helekar, Santosh A; Tchernichovski, Ofer; Voss, Henning U

2017-08-11

In many songbird species, males sing to attract females and repel rivals. How can gregarious, non-territorial songbirds such as zebra finches, where females have access to numerous males, sustain monogamy? We found that the dopaminergic reward circuitry of zebra finches can simultaneously promote social cohesion and breeding boundaries. Surprisingly, in unmated males but not in females, striatal dopamine neurotransmission was elevated after hearing songs. Behaviorally too, unmated males but not females persistently exchanged mild punishments in return for songs. Song reinforcement diminished when dopamine receptors were blocked. In females, we observed song reinforcement exclusively to the mate's song, although their striatal dopamine neurotransmission was only slightly elevated. These findings suggest that song-triggered dopaminergic activation serves a dual function in social songbirds: as low-threshold social reinforcement in males and as ultra-selective sexual reinforcement in females. Co-evolution of sexually dimorphic reinforcement systems can explain the coexistence of gregariousness and monogamy.

Sexual dimorphism in striatal dopaminergic responses promotes monogamy in social songbirds

PubMed Central

Hyland Bruno, Julia; Ljubičić, Iva; Kothari, Paresh J; Helekar, Santosh A; Tchernichovski, Ofer; Voss, Henning U

2017-01-01

In many songbird species, males sing to attract females and repel rivals. How can gregarious, non-territorial songbirds such as zebra finches, where females have access to numerous males, sustain monogamy? We found that the dopaminergic reward circuitry of zebra finches can simultaneously promote social cohesion and breeding boundaries. Surprisingly, in unmated males but not in females, striatal dopamine neurotransmission was elevated after hearing songs. Behaviorally too, unmated males but not females persistently exchanged mild punishments in return for songs. Song reinforcement diminished when dopamine receptors were blocked. In females, we observed song reinforcement exclusively to the mate’s song, although their striatal dopamine neurotransmission was only slightly elevated. These findings suggest that song-triggered dopaminergic activation serves a dual function in social songbirds: as low-threshold social reinforcement in males and as ultra-selective sexual reinforcement in females. Co-evolution of sexually dimorphic reinforcement systems can explain the coexistence of gregariousness and monogamy. PMID:28826502

Commentary: Hebephilia--a would-be paraphilia caught in the twilight zone between prepubescence and adulthood.

PubMed

Prentky, Robert; Barbaree, Howard

2011-01-01

This commentary addresses the controversy surrounding the proposed Diagnostic and Statistical Manual of Mental Disorders, Fifth Revision (DSM-5) diagnosis of pedohebephilia. We examine adult male sexual attraction to young pubescent females and whether such attraction is deviant and constitutes a mental disorder, and, independent of that question, whether there is any defensible basis for asserting that hebephilia is a legitimate paraphilia. We conclude our analysis by looking at three profiles: adults with sexualized interest in pre- and postpubescent children, adults with sexualized interest in adult and pubescent adolescent women, and adults with exclusive sexualized interest in young pubescent women. We suggest that in the third instance of exclusivity, the Criterion B requirement of impairment may become critical to legitimizing a diagnosis of hebephilia.

Same-Sex Sexuality and Adolescent Psychological Well-Being: The influence of sexual orientation, early reports of same-sex attraction, and gender

PubMed Central

Jager, Justin; Davis-Kean, Pamela E.

2012-01-01

Emerging research has shown that those of sexual-minority (SM) status (i.e., those exhibiting same-sex sexuality) report lower levels of psychological well-being. This study aimed to assess whether this relation is largely in place by the onset of adolescence, as it is for other social statuses, or whether it continues to emerge over the adolescent years, a period when SM youth face numerous challenges. Moreover, the moderating influence of sexual orientation (identification), early (versus later) reports of same-sex attractions, and gender were also examined. Using data from Add Health, multiple-group latent growth curve analyses were conducted to examine growth patterns in depressive affect and self-esteem. Results suggested that psychological well-being disparities between SM and non-SM were generally in place by early adolescence. For many, the remainder of adolescence was a recovery period when disparities narrowed over time. Early and stable reporting of same-sex attractions was associated with a greater initial deficit in psychological well-being, especially among males, but it was also associated with more rapid recovery. Independent of the timing and stability of reported same-sex attractions over time, actual sexual orientation largely failed to moderate the relation between SM status and psychological well-being. Importantly, the sizable yet understudied subgroup that identified as heterosexual but reported same-sex attractions appeared to be at substantial risk. PMID:22505839

Gender Differences in Sexual Attraction and Moral Judgment: Research With Artificial Face Models.

PubMed

González-Álvarez, Julio; Cervera-Crespo, Teresa

2018-01-01

Sexual attraction in humans is influenced by cultural or moral factors, and some gender differences can emerge in this complex interaction. A previous study found that men dissociate sexual attraction from moral judgment more than women do. Two experiments consisting of giving attractiveness ratings to photos of real opposite-sex individuals showed that men, compared to women, were significantly less influenced by the moral valence of a description about the person shown in each photo. There is evidence of some processing differences between real and artificial computer-generated faces. The present study tests the robustness of González-Álvarez's findings and extends the research to an experimental design using artificial face models as stimuli. A sample of 88 young adults (61 females and 27 males, average age 19.32, SD = 2.38) rated the attractiveness of 80 3D artificial face models generated with the FaceGen Modeller 3.5 software. Each face model was paired with a "good" and a "bad" (from a moral point of view) sentence depicting a quality or activity of the person represented in the model (e.g., she/he is an altruistic nurse in Africa vs. she/he is a prominent drug dealer). Results were in line with the previous findings and showed that, with artificial faces as well, sexual attraction is less influenced by morality in men than in women. This gender difference is consistent with an evolutionary perspective on human sexuality.

The masculinity paradox: facial masculinity and beardedness interact to determine women's ratings of men's facial attractiveness.

PubMed

Dixson, B J W; Sulikowski, D; Gouda-Vossos, A; Rantala, M J; Brooks, R C

2016-11-01

In many species, male secondary sexual traits have evolved via female choice as they confer indirect (i.e. genetic) benefits or direct benefits such as enhanced fertility or survival. In humans, the role of men's characteristically masculine androgen-dependent facial traits in determining men's attractiveness has presented an enduring paradox in studies of human mate preferences. Male-typical facial features such as a pronounced brow ridge and a more robust jawline may signal underlying health, whereas beards may signal men's age and masculine social dominance. However, masculine faces are judged as more attractive for short-term relationships over less masculine faces, whereas beards are judged as more attractive than clean-shaven faces for long-term relationships. Why such divergent effects occur between preferences for two sexually dimorphic traits remains unresolved. In this study, we used computer graphic manipulation to morph male faces varying in facial hair from clean-shaven, light stubble, heavy stubble and full beards to appear more (+25% and +50%) or less (-25% and -50%) masculine. Women (N = 8520) were assigned to treatments wherein they rated these stimuli for physical attractiveness in general, for a short-term liaison or a long-term relationship. Results showed a significant interaction between beardedness and masculinity on attractiveness ratings. Masculinized and, to an even greater extent, feminized faces were less attractive than unmanipulated faces when all were clean-shaven, and stubble and beards dampened the polarizing effects of extreme masculinity and femininity. Relationship context also had effects on ratings, with facial hair enhancing long-term, and not short-term, attractiveness. Effects of facial masculinization appear to have been due to small differences in the relative attractiveness of each masculinity level under the three treatment conditions and not to any change in the order of their attractiveness. Our findings suggest that beardedness may be attractive when judging long-term relationships as a signal of intrasexual formidability and the potential to provide direct benefits to females. More generally, our results hint at a divergence of signalling function, which may result in a subtle trade-off in women's preferences, for two highly sexually dimorphic androgen-dependent facial traits. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

The neurodevelopment of human sexual orientation.

PubMed

Rahman, Qazi

2005-01-01

One of the most enduring and controversial questions in the neuroscience of sexual behaviour surrounds the mechanisms which produce sexual attraction to either males or females. Here, evidence is reviewed which supports the proposal that sexual orientation in humans may be laid down in neural circuitry during early foetal development. Behaviour genetic investigations provide strong evidence for a heritable component to male and female sexual orientation. Linkage studies are partly suggestive of X-linked loci although candidate gene studies have produced null findings. Further evidence demonstrates a role for prenatal sex hormones which may influence the development of a putative network of sexual-orientation-related neural substrates. However, hormonal effects are often inconsistent and investigations rely heavily on 'proxy markers'. A consistent fraternal birth order effect in male sexual orientation also provides support for a model of maternal immunization processes affecting prenatal sexual differentiation. The notion that non-heterosexual preferences may reflect generalized neurodevelopmental perturbations is not supported by available data. These current theories have left little room for learning models of sexual orientation. Future investigations, across the neurosciences, should focus to elucidate the fundamental neural architecture underlying the target-specific direction of human sexual orientation, and their antecedents in developmental neurobiology.

Intra- and Intersexual swim bladder dimorphisms in the plainfin midshipman fish (Porichthys notatus): Implications of swim bladder proximity to the inner ear for sound pressure detection.

PubMed

Mohr, Robert A; Whitchurch, Elizabeth A; Anderson, Ryan D; Forlano, Paul M; Fay, Richard R; Ketten, Darlene R; Cox, Timothy C; Sisneros, Joseph A

2017-11-01

The plainfin midshipman fish, Porichthys notatus, is a nocturnal marine teleost that uses social acoustic signals for communication during the breeding season. Nesting type I males produce multiharmonic advertisement calls by contracting their swim bladder sonic muscles to attract females for courtship and spawning while subsequently attracting cuckholding type II males. Here, we report intra- and intersexual dimorphisms of the swim bladder in a vocal teleost fish and detail the swim bladder dimorphisms in the three sexual phenotypes (females, type I and II males) of plainfin midshipman fish. Micro-computerized tomography revealed that females and type II males have prominent, horn-like rostral swim bladder extensions that project toward the inner ear end organs (saccule, lagena, and utricle). The rostral swim bladder extensions were longer, and the distance between these swim bladder extensions and each inner-ear end organ type was significantly shorter in both females and type II males compared to that in type I males. Our results revealed that the normalized swim bladder length of females and type II males was longer than that in type I males while there was no difference in normalized swim bladder width among the three sexual phenotypes. We predict that these intrasexual and intersexual differences in swim bladder morphology among midshipman sexual phenotypes will afford greater sound pressure sensitivity and higher frequency detection in females and type II males and facilitate the detection and localization of conspecifics in shallow water environments, like those in which midshipman breed and nest. © 2017 Wiley Periodicals, Inc.

What Leads to Sex? Adolescent Preferred Partners and Reasons for Sex.

ERIC Educational Resources Information Center

Eyre, Stephen L.; Millstein, Susan G.

1999-01-01

Examined perceived antecedents of sex and preferred partner qualities in African-American and White late adolescents. Found that African Americans mentioned "nice body" as criterion for partner attractiveness; Whites did not. Males identified sexual arousal as a reason for sex; females did not. African-American males associated sexual…

Social Networks and Risk for Depressive Symptoms in a National Sample of Sexual Minority Youth

PubMed Central

Hatzenbuehler, Mark L.; McLaughlin, Katie A.; Xuan, Ziming

2012-01-01

The aim of the study was to examine the social networks of sexual minority youths and to determine the associations between social networks and depressive symptoms. Data were obtained from the National Longitudinal Study of Adolescent Health (Add Health), a nationally representative cohort study of American adolescents (N=14,212). Wave 1 (1994–1995) collected extensive information about the social networks of participants through peer nomination inventories, as well as measures of sexual minority status and depressive symptoms. Using social network data, we examined three characteristics of adolescents’ social relationships: (1) social isolation; (2) degree of connectedness; and (3) social status. Sexual minority youths, particularly females, were more isolated, less connected, and had lower social status in peer networks than opposite-sex attracted youths. Among sexual minority male (but not female) youths, greater isolation as well as lower connectedness and status within a network were associated with greater depressive symptoms. Moreover, greater isolation in social networks partially explained the association between sexual minority status and depressive symptoms among males. Finally, a significant 3-way interaction indicated that the association between social isolation and depression was stronger for sexual minority male youths than non-minority youths and sexual minority females. These results suggest that the social networks in which sexual minority male youths are embedded may confer risk for depressive symptoms, underscoring the importance of considering peer networks in both research and interventions targeting sexual minority male adolescents. PMID:22771037

Social networks and risk for depressive symptoms in a national sample of sexual minority youth.

PubMed

Hatzenbuehler, Mark L; McLaughlin, Katie A; Xuan, Ziming

2012-10-01

The aim of the study was to examine the social networks of sexual minority youths and to determine the associations between social networks and depressive symptoms. Data were obtained from the National Longitudinal Study of Adolescent Health (Add Health), a nationally representative cohort study of American adolescents (N = 14,212). Wave 1 (1994-1995) collected extensive information about the social networks of participants through peer nomination inventories, as well as measures of sexual minority status and depressive symptoms. Using social network data, we examined three characteristics of adolescents' social relationships: (1) social isolation; (2) degree of connectedness; and (3) social status. Sexual minority youths, particularly females, were more isolated, less connected, and had lower social status in peer networks than opposite-sex attracted youths. Among sexual minority male (but not female) youths, greater isolation as well as lower connectedness and status within a network were associated with greater depressive symptoms. Moreover, greater isolation in social networks partially explained the association between sexual minority status and depressive symptoms among males. Finally, a significant 3-way interaction indicated that the association between social isolation and depression was stronger for sexual minority male youths than non-minority youths and sexual minority females. These results suggest that the social networks in which sexual minority male youths are embedded may confer risk for depressive symptoms, underscoring the importance of considering peer networks in both research and interventions targeting sexual minority male adolescents. Copyright © 2012 Elsevier Ltd. All rights reserved.

Senescence in immune priming and attractiveness in a beetle.

PubMed

Daukšte, J; Kivleniece, I; Krama, T; Rantala, M J; Krams, I

2012-07-01

Age-related decline in immune activity is referred to as immunosenescence and has been observed for both the adaptive immune response of vertebrates and the innate immune system of invertebrates. Because maintaining a basic level of immune defence and mounting an immune response is costly, optimal investment in immune function should vary over a wide range of individual states such as the individual's age. In this study, we tested whether the immune response and immunological priming within individuals become less efficient with age using mealworm beetles, Tenebrio molitor, as a model organism. We also tested whether ageing and immunological priming affected the odours produced by males. We found that young males of T. molitor were capable of mounting an immune response a sterile nylon monofilament implant with the potential to exhibit a simple form of immune memory through mechanisms of immune priming. Older males did not increase their immune response to a second immune challenge, which negatively affected their sexual attractiveness and remaining life span. Our results indicate that the immune system of older males in T. molitor is less effective, suggesting complex evolutionary trade-offs between ageing, immune response and sexual attractiveness. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

A multidimensional measure of sexual orientation, use of psychoactive substances, and depression: results of a national survey on sexual behavior in france.

PubMed

Lhomond, Brigitte; Saurel-Cubizolles, Marie-Josèphe; Michaels, Stuart

2014-04-01

Using data from a large national representative survey on sexual behavior in France (Contexte de la Sexualité en France), this study analyzed the relationship between a multidimensional measure of sexual orientation and psychoactive substance use and depression. The survey was conducted in 2006 by telephone with a random sample of the continental French speaking population between the ages of 18 and 69 years. The sample used for this analysis consisted of the 4,400 men and 5,472 women who were sexually active. A sexual orientation measure was constructed by combining information on three dimensions of sexual orientation: attraction, sexual behavior, and self-definition. Five mutually exclusive groups were defined for men and women: those with only heterosexual behavior were divided in two groups whether or not they declared any same-sex attraction; those with any same-sex partners were divided into three categories derived from their self-definition (heterosexual, bisexual or homosexual). The consumption of alcohol and cannabis, which was higher in the non-exclusively heterosexual groups, was more closely associated with homosexual self-identification for women than for men. Self-defined bisexuals (both male and female) followed by gay men and lesbians had the highest risk of chronic or recent depression. Self-defined heterosexuals who had same-sex partners or attraction had levels of risk between exclusive heterosexuals and self-identified homosexuals and bisexuals. The use of a multidimensional measure of sexual orientation demonstrated variation in substance use and mental health between non-heterosexual subgroups defined in terms of behavior, attraction, and identity.

Fraternal birth order and sexual orientation in pedophiles.

PubMed

Blanchard, R; Barbaree, H E; Bogaert, A F; Dickey, R; Klassen, P; Kuban, M E; Zucker, K J

2000-10-01

Whether homosexual pedophiles have more older brothers (a higher fraternal birth order) than do heterosexual pedophiles was investigated. Subjects were 260 sex offenders (against children age 14 or younger) and 260 matched volunteer controls. The subject's relative attraction to male and female children was assessed by phallometric testing in one analysis, and by his offense history in another. Both methods showed that fraternal birth order correlates with homosexuality in pedophiles, just as it does in men attracted to physically mature partners. Results suggest that fraternal birth order (or the underlying variable it represents) may prove the first identified universal factor in homosexual development. Results also argue against a previous explanation of the high prevalence of homosexuality in pedophiles (25% in this study), namely, that the factors that determine sexual preference in pedophiles are different from those that determine sexual preference in men attracted to adults. An alternative explanation in terms of canalization of development is suggested.

Sexy Mouth Odour? Male Oral Gland Pheromone in the Grain Beetle Parasitoid Lariophagus distinguendus (Förster) (Hymenoptera: Pteromalidae).

PubMed

König, Kerstin; Seeger, Lucy; Steidle, Johannes L M

2015-01-01

Throughout the animal kingdom, sexual pheromones are used for the attraction of mates and as courtship signals but also enable sexual isolation between species. In the parasitic wasp Lariophagus distinguendus, male courtship behaviour consisting of wing fanning, antennal stroking of the female antenna, and head nodding stimulates female receptivity leading to copulation. Recently L. distinguendus was reported to consist of two different lineages, which are sexually isolated because males fail to elicit receptivity in foreign females. It is unclear, however, which part of the courtship behaviour triggers female receptivity and therefore could be a mechanism causing sexual isolation. Here we show that in L. distinguendus a nonvolatile male oral pheromone is essential to release the female receptivity signal. In contrast, male wing fanning and antennal contact play a minor role. Additionally, the composition of the oral pheromone depends on the developmental host and females learn the composition upon emergence from the host substrate. These results will enable more detailed work on oral sexual pheromones to answer the question of how they are involved in the speciation process of L. distinguendus and other parasitoid species, for a better understanding of the huge biodiversity in this group.

The shield effect: nuptial gifts protect males against pre-copulatory sexual cannibalism

PubMed Central

Albo, Maria J.

2016-01-01

Several not mutually exclusive functions have been ascribed to nuptial gifts across different taxa. Although the idea that a nuptial prey gift may protect the male from pre-copulatory sexual cannibalism is attractive, it has previously been considered of no importance based on indirect evidence and rejected by experimental tests. We reinvestigated whether nuptial gifts may function as a shield against female attacks during mating encounters in the spider Pisaura mirabilis and whether female hunger influences the likelihood of cannibalistic attacks. The results showed that pre-copulatory sexual cannibalism was enhanced when males courted without a gift and this was independent of female hunger. We propose that the nuptial gift trait has evolved partly as a counteradaptation to female aggression in this spider species. PMID:27194284

The shield effect: nuptial gifts protect males against pre-copulatory sexual cannibalism.

PubMed

Toft, Søren; Albo, Maria J

2016-05-01

Several not mutually exclusive functions have been ascribed to nuptial gifts across different taxa. Although the idea that a nuptial prey gift may protect the male from pre-copulatory sexual cannibalism is attractive, it has previously been considered of no importance based on indirect evidence and rejected by experimental tests. We reinvestigated whether nuptial gifts may function as a shield against female attacks during mating encounters in the spider Pisaura mirabilis and whether female hunger influences the likelihood of cannibalistic attacks. The results showed that pre-copulatory sexual cannibalism was enhanced when males courted without a gift and this was independent of female hunger. We propose that the nuptial gift trait has evolved partly as a counteradaptation to female aggression in this spider species. © 2016 The Author(s).

Women's Drinking Decisions in Heterosocial Situations: Development and Validation of Scenarios to Assess Influence of Attraction and Risk-Awareness.

PubMed

Noel, Nora E; Ogle, Richard L; Maisto, Stephen A; Jackson, Lee A; Loomis, Randi B; Heaton, Jennifer A

2016-07-01

These three related studies created a set of ecologically valid scenarios for assessing relative associations of both attraction and sexual coercion risk-recognition in college women's heterosocial situational drinking decisions. The first study constructed nine scenarios using input from heterosexual drinking women in the age cohort (18-30) most likely to experience alcohol-related sexual coercion. In the second study, 50 female undergraduates (ages 18-25) assessed the salience of three important dimensions (attraction, risk, and realism) in these scenarios. The third study was a factor analysis (and a follow-up confirmatory factor analysis) of the elements of coercion-risk as perceived by the target group with two female samples recruited 1 year apart (Sample 1: N = 157, ages 18-29); Sample 2: N = 157, ages 18-30). Results confirmed that the scenarios could be a useful vehicle for assessing how women balance out risk and attraction to make in-the moment heterosocial drinking decisions. The factor analysis showed participants perceived two types of situations, based on whether the male character was "Familiar" or "Just Met" and perceived themselves as happier and more excited with Familiar males. However, in contrast to HIV risk studies, Familiar males were perceived as higher risk for unwanted sex. Future research will use the six scenarios that emerged from the factor analysis to study how attraction and risk perception differentially affect young adult women's social drinking decisions.

The role of juvenile hormone in immune function and pheromone production trade-offs: a test of the immunocompetence handicap principle.

PubMed Central

Rantala, Markus J; Vainikka, Anssi; Kortet, Raine

2003-01-01

The immunocompetence handicap hypothesis postulates that secondary sexual traits are honest signals of mate quality because the hormones (e.g. testosterone) needed to develop secondary sexual traits have immunosuppressive effects. The best support for predictions arising from the immunocompetence handicap hypothesis so far comes from studies of insects, although they lack male-specific hormones such as testosterone. In our previous studies, we found that female mealworm beetles prefer pheromones of immunocompetent males. Here, we tested how juvenile hormone (JH) affects male investment in secondary sexual characteristics and immune functions in the mealworm beetle, Tenebrio molitor. We injected male mealworm beetles with JH (type III) and found that injection increased the attractiveness of male pheromones but simultaneously suppressed immune functions (phenoloxidase activity and encapsulation). Our results suggest that JH, which is involved in the control of reproduction and morphogenesis, also plays a central role in the regulation of a trade-off between the immune system and sexual advertisement in insects. Thus, the results reflect a general mechanism by which the immunocompetence handicap hypothesis may work in insects. PMID:14613612

Tolerance of sexual harassment: a laboratory paradigm.

PubMed

Angelone, David J; Mitchell, Damon; Carola, Kara

2009-12-01

The present study attempted to develop a laboratory analogue for the study of tolerance for sexual harassment by using an online speed-dating paradigm. In that context, the relation between participants' sexual harassment attitudes, perpetrator attractiveness, perpetrator status, and perceived dating potential of the perpetrator were examined as factors influencing participants' tolerance of sexually harassing behavior. Participants were 128 female college students from a small northeastern public university. Results indicated that attractiveness, high social status, and attitudinal beliefs about sexual harassment were all predictive of tolerance for sexual harassment, providing preliminary support for the validity of this paradigm. In addition, participants' self reported likelihood to date a bogus male dating candidate was also predictive of tolerance for sexual harassment, over and above the aforementioned variables, suggesting that dating potential can play a role in perceptions of sexual harassment. Further, this experiment demonstrated that perceptions of sexual harassment can be assessed using the in vivo measurement of behavior. In addition, using an online environment not only provides a contemporary spin and adds a greater degree of external validity compared to other sexual harassment analogues, it also reduces any risk of potential physical sexual contact for participants.

Self-reported impulsivity, rather than sociosexuality, predicts women's preferences for masculine features in male faces.

PubMed

Boothroyd, Lynda G; Brewer, Gayle

2014-07-01

Previous research has suggested that an individual's sociosexual orientation (i.e., their willingness to engage in sexual behavior outside of long-term relationships) may influence the qualities they find attractive in a potential mate. Results, however, have not been consistent and, moreover, studies have tended to draw from specific social groups. Here, we tested the relationship between sociosexuality and female's preferences for masculinity in male faces, using a diverse population. We furthermore investigated impulsivity alongside sociosexuality, as this trait has been suggested as a "root" cause of variation in sexual behavior (Cross, 2010) and thus may better explain variation in mate choice. Results showed a significant association between increases in both sociosexuality and two subcomponents of impulsivity and greater preferences for masculine male features. Regression analysis suggested that a subcomponent of impulsivity, namely lack of planning, was the primary determinant of preferences. We discuss the implications these results have for our understanding of female attraction to masculine features.

Health Risks in Same-Sex Attracted Ugandan University Students: Evidence from Two Cross-Sectional Studies

PubMed Central

Agardh, Anette; Ross, Michael; Östergren, Per-Olof; Larsson, Markus; Tumwine, Gilbert; Månsson, Sven-Axel; Simpson, Julie A.; Patton, George

2016-01-01

Widespread discrimination across much of sub-Saharan Africa against persons with same-sex sexuality, including recent attempts in Uganda to extend criminal sanctions against same-sex behavior, are likely to have profound effects on this group’s health, health care access, and well-being. Yet knowledge of the prevalence of same-sex sexuality in this region is scarce. This study aimed to systematically examine prevalence of same-sex sexuality and related health risks in young Ugandan adults. We conducted two cross-sectional survey studies in south-western Uganda targeting student samples (n = 980, n = 1954) representing 80% and 72% of the entire undergraduate classes attending a university in 2005 and 2010, respectively. A questionnaire assessed items concerning same-sex sexuality (same-sex attraction/fantasies, same-sex sexual relations), mental health, substance use, experience of violence, risky sexual behavior, and sexual health counseling needs. Our findings showed that same-sex sexual attraction/fantasies and behavior were common among male and female students, with 10–25% reporting having sexual attraction/fantasies regarding persons of the same-sex, and 6–16% reporting same-sex sexual relations. Experiences of same-sex sexuality were associated with health risks, e.g. poor mental health (2010, AOR = 1.5; 95% CI: 1.0–2.3), sexual coercion (2010, AOR 2.9; CI: 1.9–4.6), and unmet sexual health counseling needs (2010, AOR 2.2; CI: 1.4–3.3). This first study of young adults in Uganda with same-sex sexuality found high levels of health needs but poor access to health care. Effective response is likely to require major shifts in current policy, efforts to reduce stigmatization, and reorientation of health services to better meet the needs of this vulnerable group of young people. PMID:26982494

Rethinking sexual initiation: pathways to identity formation among gay and bisexual Mexican male youth.

PubMed

Carrillo, Héctor; Fontdevila, Jorge

2011-12-01

The topic of same-sex sexual initiation has generally remained understudied in the literature on sexual identity formation among sexual minority youth. This article analyzes the narratives of same-sex sexual initiation provided by 76 gay and bisexual Mexican immigrant men who participated in interviews for the Trayectos Study, an ethnographic study of sexuality and HIV risk. These participants were raised in a variety of locations throughout Mexico, where they also realized their same-sex attraction and initiated their sexual lives with men. We argue that Mexican male same-sex sexuality is characterized by three distinct patterns of sexual initiation--one heavily-based on gender roles, one based on homosociality, and one based on object choice--which inform the men's interpretations regarding sexual roles, partner preferences, and sexual behaviors. We analyzed the social factors and forms of cultural/sexual socialization that lead sexual minority youth specifically to each of these three patterns of sexual initiation. Our findings confirm the importance of studying same-sex sexual initiation as a topic in its own right, particularly as a tool to gain a greater understanding of the diversity of same-sex sexual experiences and sexual identities within and among ethnic/cultural groups.

Stress hormone is implicated in satellite-caller associations and sexual selection in the Great Plains toad.

PubMed

Leary, Christopher J; Garcia, Apryl M; Knapp, Rosemary

2006-10-01

The effects of androgens on male-typical traits suggest that variation among males in circulating levels can play a major role in sexual selection. We examined whether variation in vocal attractiveness is attributable to differences in androgen levels among Great Plains toads (Bufo cognatus). We found that noncalling "satellite" males practicing an alternative mating tactic were more likely to associate with males producing long calls. However, callers with satellites did not have higher androgen levels than callers without satellites. Rather, callers with satellites had significantly lower corticosterone (CORT) levels than callers without satellites. A CORT manipulation experiment suggested that differences in calls for males with and without satellites were related to differences in CORT levels. Furthermore, there was a negative correlation between CORT level and call duration within most nights of chorus activity. However, the correlation was weak for the pooled data (across all nights), suggesting that local environmental and/or social factors also affect call duration. Last, we show that females preferred broadcast calls of longer duration, characteristic of males with satellites and low CORT. These results imply that satellites optimize their reproductive success by associating with males producing long calls. However, this association should negatively affect the fitness of attractive callers.

The Effects of Gender and Relationship Context Cues on Responsive Sexual Desire in Exclusively and Predominantly Androphilic Women and Gynephilic Men.

PubMed

Timmers, Amanda D; Dawson, Samantha J; Chivers, Meredith L

2018-04-20

Sexual desire may be "responsive," emerging from sexual arousal to sexually competent cues. Cues that elicit sexual arousal and desire differ, however, by gender and direction of sexual attractions. Further, relationship context cues are thought to be important for responsive desire, but this has not been tested directly. The current study examined gynephilic men's (n = 27) and exclusively (n = 23) and predominantly (n = 17) androphilic women's dyadic and solitary responsive sexual desire, as well as genital and self-reported arousal, to audio narratives varying by gender (male, female) of the sexual partner and relationship context (stranger, friend, long-term relationship). Consistent with previous literature, gynephilic men's solitary and dyadic desire were gender-specific (greater to female than to male sexual partners). Exclusively androphilic women's dyadic desire differentiated less to cues of gender than gynephilic men's, and their solitary desire did not differentiate by gender cues at all, replicating previous research. Androphilic women with some gynephilia reported a gender-nonspecific pattern of dyadic and solitary desire (i.e., responsive desire to both male and female narratives). No effect of relationship context was found for any groups. Results suggest that responsive sexual desire may be more closely associated with self-reported than genital arousal patterns.

Sex-typicality and attractiveness: are supermale and superfemale faces super-attractive?

PubMed

Rhodes, G; Hickford, C; Jeffery, L

2000-02-01

Many animals find extreme versions of secondary sexual characteristics attractive, and such preferences can enhance reproductive success (Andersson, 1994). We hypothesized, therefore, that extreme versions of sex-typical traits may be attractive in human faces. We created supermale and superfemale faces by exaggerating all spatial differences between an average male and an average female face. In Expt 1 the male average was preferred to a supermale (50% exaggeration of differences from the female average). There was no clear preference for the female average or the superfemale (50% exaggeration). In Expt 2, participants chose the most attractive face from sets of images containing feminized as well as masculinized images for each sex, and spanning a wider range of exaggeration levels than in Expt 1. Chinese sets were also shown, to see whether similar preferences would occur for a less familiar race (participants were Caucasian). The most attractive female image was significantly feminized for faces of both races. However, the most attractive male image for both races was also significantly feminized. These results indicate that feminization, rather than sex exaggeration per se, is attractive in human faces, and they corroborate similar findings by Perrett et al. (1998).

Influences of observer sex, facial masculinity, and gender role identification on first impressions of men’s faces

PubMed Central

Macapagal, Kathryn R.; Rupp, Heather A.; Heiman, Julia R.

2011-01-01

Evaluations of male faces depend on attributes of the observer and target and may influence future social and sexual decisions. However, it is unknown whether adherence to hypertraditional gender roles may shape women’s evaluations of potential sexual partners or men’s evaluations of potential competitors. Using a photo task, we tested participants’ judgments of attractiveness, trustworthiness, aggressiveness, and masculinity of male faces altered to appear more masculine or feminine. Findings revealed that higher hypermasculinity scores in male observers were correlated with higher attractiveness and trustworthiness ratings of the male faces; conversely, higher hyperfemininity scores in female observers were associated with lower ratings on those traits. Male observers also rated the faces as more aggressive than did female observers. Regarding ratings by face type, masculinized faces were rated more aggressive than feminized faces, and women’s ratings did not discriminate between altered faces better than men’s ratings. These results suggest that first impressions of men can be explained in part by socioculturally- and evolutionarily-relevant factors such as the observer’s sex and gender role adherence, as well as the target’s facial masculinity. PMID:21874151

The Accessory Olfactory System Facilitates the Recovery of the Attraction to Familiar Volatile Female Odors in Male Mice.

PubMed

Muroi, Yoshikage; Nishimura, Masakazu; Ishii, Toshiaki

2017-10-31

Odors in female mice induce sexual arousal in male mice. Repeated exposure to female odors attenuates male attraction, which recovers when the odors are removed. The neuronal mechanisms for the recovery of male attraction have not been clarified. In this study, we examined how olfactory systems are involved in the recovery of male attraction to female odors following habituation in mice. Presentation with volatile female odors for 5 min induced habituation in males. To evaluate male attraction to familiar volatile female odors, we measured the duration for investigating volatile female odors from the same female mouse, which was presented twice for 5 min with 1-, 3-, or 5-min interval. Intranasal irrigation with ZnSO4 solution almost completely suppressed investigating behavior, indicating that the main olfactory system is indispensable for inducing the attraction to volatile female odors. In contrast, removal of the vomeronasal organ, bilateral lesions of the accessory olfactory bulb (AOB), or pharmacological blockage of neurotransmission in the AOB did not affect the investigation time at the first odor presentation. However, each one of the treatments decreased the investigation time in the second presentation, compared to that in the first presentation, at longer intervals than control treatment, indicating that the disturbance of neurotransmission in the accessory olfactory system delayed the recovery of the attraction attenuated by the first presentation. These results suggest that the accessory olfactory system facilitates the recovery of the attraction to familiar volatile female odors in male mice. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Female penis, male vagina, and their correlated evolution in a cave insect.

PubMed

Yoshizawa, Kazunori; Ferreira, Rodrigo L; Kamimura, Yoshitaka; Lienhard, Charles

2014-05-05

Sex-specific elaborations are common in animals and have attracted the attention of many biologists, including Darwin [1]. It is accepted that sexual selection promotes the evolution of sex-specific elaborations. Due to the faster replenishment rate of gametes, males generally have higher potential reproductive and optimal mating rates than females. Therefore, sexual selection acts strongly on males [2], leading to the rapid evolution and diversification of male genitalia [3]. Male genitalia are sometimes used as devices for coercive holding of females as a result of sexual conflict over mating [4, 5]. In contrast, female genitalia are usually simple. Here we report the reversal of intromittent organs in the insect genus Neotrogla (Psocodea: Prionoglarididae) from Brazilian caves. Females have a highly elaborate, penis-like structure, the gynosome, while males lack an intromittent organ. The gynosome has species-specific elaborations, such as numerous spines that fit species-specific pouches in the simple male genital chamber. During prolonged copulation (~40-70 hr), a large and potentially nutritious ejaculate is transferred from the male via the gynosome. The correlated genital evolution in Neotrogla is probably driven by reversed sexual selection with females competing for seminal gifts. Nothing similar is known among sex-role reversed animals. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Sexual orientation and partner-choice of transsexual women and men before gender-confirming interventions].

PubMed

Cerwenka, Susanne; Nieder, Timo Ole; Richter-Appelt, Hertha

2012-06-01

Diverse partner relationship constellations of gender dysphoric women and men with different sexual orientations are explored in a sample of 93 persons before gender-confirming interventions in persons with female gender identity and male body characteristics (MF) and persons with male gender identity and female body characteristics (FM). While in both gender groups the majority is single, relationship patterns show differences. Apart from working life, FM already live predominantly in the new, male gender role and have partners by whom they are desired as males. In contrast, only a small proportion of MF already conduct their private lives in the new, female gender role, and they often have relationships with partners sexually attracted to males and not to their female gender identity. The findings indicate a need for differing resources for gender dysphoric women and men in the process of a transsexual course of development. © Georg Thieme Verlag KG Stuttgart · New York.

Sexual and natural selection in the evolution of extended phenotypes: the use of green nesting material in starlings.

PubMed

Rubalcaba, J G; Polo, V; Maia, R; Rubenstein, D R; Veiga, J P

2016-08-01

Although sexual selection is typically considered the predominant force driving the evolution of ritualized sexual behaviours, natural selection may also play an important and often underappreciated role. The use of green aromatic plants among nesting birds has been interpreted as a component of extended phenotype that evolved either via natural selection due to potential sanitary functions or via sexual selection as a signal of male attractiveness. Here, we compared both hypotheses using comparative methods in starlings, a group where this behaviour is widespread. We found that the use of green plants was positively related to male-biased size dimorphism and that it was most likely to occur among cavity-nesting species. These results suggest that this behaviour is likely favoured by sexual selection, but also related to its sanitary use in response to higher parasite loads in cavities. We speculate that the use of green plants in starlings may be facilitated by cavity nesting and was subsequently co-opted as a sexual signal by males. Our results represent an example of how an extended phenotypic component of males becomes sexually selected by females. Thus, both natural selection and sexual selection are necessary to fully understand the evolution of ritualized behaviours involved in courtship. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

A specialized fungal parasite (Massospora cicadina) hijacks the sexual signals of periodical cicadas (Hemiptera: Cicadidae: Magicicada).

PubMed

Cooley, John R; Marshall, David C; Hill, Kathy B R

2018-01-23

Male periodical cicadas (Magicicada spp.) infected with conidiospore-producing ("Stage I") infections of the entomopathogenic fungus Massospora cicadina exhibit precisely timed wing-flick signaling behavior normally seen only in sexually receptive female cicadas. Male wing-flicks attract copulation attempts from conspecific males in the chorus; close contact apparently spreads the infective conidiospores. In contrast, males with "Stage II" infections that produce resting spores that wait for the next cicada generation do not produce female-specific signals. We propose that these complex fungus-induced behavioral changes, which resemble apparently independently derived changes in other cicada-Massospora systems, represent a fungus "extended phenotype" that hijacks cicadas, turning them into vehicles for fungus transmission at the expense of the cicadas' own interests.

(Methylthio)phenol semiochemicals are exploited by deceptive orchids as sexual attractants for Campylothynnus thynnine wasps.

PubMed

Bohman, Björn; Phillips, Ryan D; Flematti, Gavin R; Peakall, Rod

2018-04-01

Until recently, (methylthio)phenols as natural products had only been reported from bacteria. Now, four representatives of this class of sulfurous aromatic compounds have been discovered as semiochemicals in the orchid Caladenia crebra, which secures pollination by sexual deception. In this case, field bioassays confirmed that a 10:1 blend of 2-(methylthio)benzene-1,4-diol (1) and 4-hydroxy-3-(methylthio)benzaldehyde (2) sexually attracts the male thynnine wasp Campylothynnus flavopictus (Tiphiidae:Thynnineae), the exclusive pollinator of C. crebra. Here we show with field bioassays that another undescribed species of Campylothynnus (sp. A) is strongly sexually attracted to a 1:1 blend of compounds 1 and 2, which elicits very high attempted copulation rates (88%). We also confirm that this Campylothynnus species is a pollinator of Caladenia attingens subsp. attingens. Chemical analysis of the flowers of this orchid revealed two (methylthio)phenols, compound 2 and 2-(methylthio)phenol (3), as candidate semiochemicals involved in pollinator attraction. Thus, (methylthio)phenols are likely to be more widely used than presently known. The confirmation of this Campylothynnus as a pollinator of C. attingens subsp. attingens at our study sites was unexpected, since elsewhere this orchid is pollinated by a different thynnine wasp (Thynnoides sp). In general, sexually deceptive Caladenia only use a single species of pollinator, and as such, this unusual case may offer a tractable study system for understanding the chemical basis of pollinator switching in sexually deceptive orchids. Copyright © 2017 Elsevier B.V. All rights reserved.

Who are gynandromorphophilic men? Characterizing men with sexual interest in transgender women.

PubMed

Hsu, K J; Rosenthal, A M; Miller, D I; Bailey, J M

2016-03-01

Gynandromorphophilia (GAMP) is sexual interest in gynandromorphs (GAMs; colloquially, shemales). GAMs possess a combination of male and female physical characteristics. Thus, GAMP presents a challenge to conventional understandings of sexual orientation as sexual attraction to the male v. female form. Speculation about GAMP men has included the ideas that they are homosexual, heterosexual, or especially, bisexual. We compared genital and subjective sexual arousal patterns of GAMP men with those of heterosexual and homosexual men. We also compared these groups on their self-ratings of sexual orientation and sexual interests. GAMP men had arousal patterns similar to those of heterosexual men and different from those of homosexual men. However, compared to heterosexual men, GAMP men were relatively more aroused by GAM erotic stimuli than by female erotic stimuli. GAMP men also scored higher than both heterosexual and homosexual men on a measure of autogynephilia. Results provide clear evidence that GAMP men are not homosexual. They also indicate that GAMP men are especially likely to eroticize the idea of being a woman.

Assessing paedophilia based on the haemodynamic brain response to face images.

PubMed

Ponseti, Jorge; Granert, Oliver; Van Eimeren, Thilo; Jansen, Olav; Wolff, Stephan; Beier, Klaus; Deuschl, Günther; Huchzermeier, Christian; Stirn, Aglaja; Bosinski, Hartmut; Roman Siebner, Hartwig

2016-01-01

Objective assessment of sexual preferences may be of relevance in the treatment and prognosis of child sexual offenders. Previous research has indicated that this can be achieved by pattern classification of brain responses to sexual child and adult images. Our recent research showed that human face processing is tuned to sexual age preferences. This observation prompted us to test whether paedophilia can be inferred based on the haemodynamic brain responses to adult and child faces. Twenty-four men sexually attracted to prepubescent boys or girls (paedophiles) and 32 men sexually attracted to men or women (teleiophiles) were exposed to images of child and adult, male and female faces during a functional magnetic resonance imaging (fMRI) session. A cross-validated, automatic pattern classification algorithm of brain responses to facial stimuli yielded four misclassified participants (three false positives), corresponding to a specificity of 91% and a sensitivity of 95%. These results indicate that the functional response to facial stimuli can be reliably used for fMRI-based classification of paedophilia, bypassing the problem of showing child sexual stimuli to paedophiles.

Adolescents' Clothing Purchase Motivations, Information Sources, and Store Selection Criteria: A Comparison of Male/Female and Impulse/Nonimpulse Shoppers.

ERIC Educational Resources Information Center

Chen-Yu, Jessie H.; Seock, Yoo-Kyoung

2002-01-01

Male (n=69) and female (n=68) adolescents spent similar amounts on clothing with similar conformity, sexual attractiveness, and recognition motivations. Females shopped significantly more often and were more influenced by friends and magazines. There were significant differences between impulse buyers and others in shopping frequency, expenditure,…

Influence of methoprene and dietary protein on maturation and sexual performance of sterile, Anastrepha ludens (Diptera: Tephritidae)

USDA-ARS?s Scientific Manuscript database

Juvenile hormone levels and adult diet have important effects on the attractiveness and competitiveness of the male Anastrepha ludens (Loew) (Mexican fruit fly). Since the success of the sterile insect technique requires the release of males that can compete in the wild, these effects are very impor...

A model for group counseling with male pedophiles.

PubMed

van Zessen, G

1990-01-01

Group treatment programs for pedophiles are often designed for populations of convicted men in closed institutions with limited application to other populations. Treatment is usually focused on reducing the "deviant" sexual arousal and/or acquiring heterosocial skills and eventually establishing the ability to engage in adult heterosexual relationships. A six-week, highly structured program is presented to five men in a non-residential setting. In addition to individual psychotherapy, group counseling is offered. Male pedophiles are trained to talk effectively about common problems surrounding man-boy relationships. Counseling is based on the notion that the emotional, erotic and sexual attraction to boys per se does not need to be legitimized or modified. The attraction, however, can be a source of psychological and social problems that can be handled by using a social support system. Social support for pedophile problems can be obtained from and in interaction with other pedophiles.

Pheromone evolution and sexual behavior in Drosophila are shaped by male sensory exploitation of other males.

PubMed

Ng, Soon Hwee; Shankar, Shruti; Shikichi, Yasumasa; Akasaka, Kazuaki; Mori, Kenji; Yew, Joanne Y

2014-02-25

Animals exhibit a spectacular array of traits to attract mates. Understanding the evolutionary origins of sexual features and preferences is a fundamental problem in evolutionary biology, and the mechanisms remain highly controversial. In some species, females choose mates based on direct benefits conferred by the male to the female and her offspring. Thus, female preferences are thought to originate and coevolve with male traits. In contrast, sensory exploitation occurs when expression of a male trait takes advantage of preexisting sensory biases in females. Here, we document in Drosophila a previously unidentified example of sensory exploitation of males by other males through the use of the sex pheromone CH503. We use mass spectrometry, high-performance liquid chromatography, and behavioral analysis to demonstrate that an antiaphrodisiac produced by males of the melanogaster subgroup also is effective in distant Drosophila relatives that do not express the pheromone. We further show that species that produce the pheromone have become less sensitive to the compound, illustrating that sensory adaptation occurs after sensory exploitation. Our findings provide a mechanism for the origin of a sex pheromone and show that sensory exploitation changes male sexual behavior over evolutionary time.

Artificial selection reveals sex differences in the genetic basis of sexual attractiveness.

PubMed

Gosden, Thomas P; Reddiex, Adam J; Chenoweth, Stephen F

2018-05-07

Mutual mate choice occurs when males and females base mating decisions on shared traits. Despite increased awareness, the extent to which mutual choice drives phenotypic change remains poorly understood. When preferences in both sexes target the same traits, it is unclear how evolution will proceed and whether responses to sexual selection from male choice will match or oppose responses to female choice. Answering this question is challenging, as it requires understanding, genetic relationships between the traits targeted by choice, mating success, and, ultimately, fitness for both sexes. Addressing this, we applied artificial selection to the cuticular hydrocarbons of the fly Drosophila serrata that are targeted by mutual choice and tracked evolutionary changes in males and females alongside changes in mating success. After 10 generations, significant trait evolution occurred in both sexes, but intriguingly there were major sex differences in the associated fitness consequences. Sexually selected trait evolution in males led to a genetically based increase in male mating success. By contrast, although trait evolution also occurred in females, there was no change in mating success. Our results suggest that phenotypic sexual selection on females from male choice is environmentally, rather than genetically, generated. Thus, compared with female choice, male choice is at best a weak driver of signal trait evolution in this species. Instead, the evolution of apparent female ornamentation seems more likely due to a correlated response to sexual selection on males and possibly other forms of natural selection.

Effects of potential partners' physical attractiveness and socioeconomic status on sexuality and partner selection.

PubMed

Townsend, J M; Levy, G D

1990-04-01

Male (n = 170) and female (n = 212) college students viewed photographs, which had been prerated for physical attractiveness, of three opposite-sex individuals. These photographs were paired with three levels of occupational status and income. Subjects indicated their willingness to engage in relationships of varying levels of sexual intimacy and marital potential with the portrayed individuals. Analyses of variance, correlations, and trend analyses supported the hypotheses. Compared to men, women are more likely to prefer or insist that sexual intercourse occur in relationships that involve affection and marital potential, and women place more emphasis than men do on partners' SES in such relationships. Consequently, men's SES and their willingness and ability to invest affection and resources in relationships may often outweigh the effects of their physical attractiveness in women's actual selection of partners. These results and the literature reviewed are more consistent with parental investment theory than with the view that these sex differences are solely the result of differential access to resources and differential socialization.

Sounds different: inbreeding depression in sexually selected traits in the cricket Teleogryllus commodus.

PubMed

Drayton, J M; Hunt, J; Brooks, R; Jennions, M D

2007-05-01

If male sexual signalling is honest because it captures genetic variation in condition then traits that are important mate choice cues should be disproportionately affected by inbreeding relative to other traits. To test this, we investigated the effect of brother-sister mating on advertisement calling by male field crickets Teleogryllus commodus. We quantified the effect of one generation of inbreeding on nightly calling effort and five finer-scale aspects of call structure that have been shown to influence attractiveness. We also quantified inbreeding depression on six life history traits and one morphological trait. Inbreeding significantly reduced hatching success, nymph survival and adult lifespan but had no detectable effect on hatching rate, developmental rate or adult body mass. The effect of inbreeding on sexually selected traits was equivocal. There was no decline in calling effort (seconds of sound production/night) by inbred males, but there were highly significant changes in three of five finer-scale call parameters. Sexually selected traits clearly vary in their susceptibility to inbreeding depression.

Does Masculinity Matter? The Contribution of Masculine Face Shape to Male Attractiveness in Humans

PubMed Central

Scott, Isabel M. L.; Pound, Nicholas; Stephen, Ian D.; Clark, Andrew P.; Penton-Voak, Ian S.

2010-01-01

Background In many animals, exaggerated sex-typical male traits are preferred by females, and may be a signal of both past and current disease resistance. The proposal that the same is true in humans – i.e., that masculine men are immunocompetent and attractive – underpins a large literature on facial masculinity preferences. Recently, theoretical models have suggested that current condition may be a better index of mate value than past immunocompetence. This is particularly likely in populations where pathogenic fluctuation is fast relative to host life history. As life history is slow in humans, there is reason to expect that, among humans, condition-dependent traits might contribute more to attractiveness than relatively stable traits such as masculinity. To date, however, there has been little rigorous assessment of whether, in the presence of variation in other cues, masculinity predicts attractiveness or not. Methodology/Principal Findings The relationship between masculinity and attractiveness was assessed in two samples of male faces. Most previous research has assessed masculinity either with subjective ratings or with simple anatomical measures. Here, we used geometric morphometric techniques to assess facial masculinity, generating a morphological masculinity measure based on a discriminant function that correctly classified >96% faces as male or female. When assessed using this measure, there was no relationship between morphological masculinity and rated attractiveness. In contrast, skin colour – a fluctuating, condition-dependent cue – was a significant predictor of attractiveness. Conclusions/Significance These findings suggest that facial morphological masculinity may contribute less to men's attractiveness than previously assumed. Our results are consistent with the hypothesis that current condition is more relevant to male mate value than past disease resistance, and hence that temporally fluctuating traits (such as colour) contribute more to male attractiveness than stable cues of sexual dimorphism. PMID:21048972

Flibanserin and 8-OH-DPAT implicate serotonin in association between female marmoset monkey sexual behavior and changes in pair-bond quality

PubMed Central

Aubert, Yves; Gustison, Morgan L.; Gardner, Lindsey A.; Bohl, Michael A.; Lange, Jason R.; Allers, Kelly A.; Sommer, Bernd; Datson, Nicole A.; Abbott, David H.

2018-01-01

Introduction Psychopathological origins of personally distressing, hypoactive sexual desire disorder (HSDD) in women are unknown, but are generally attributed to an inhibitory neural regulator, serotonin (5-HT). Flibanserin, a 5-HT1A agonist and 5-HT2A antagonist, shows promise as a treatment for HSDD. Aim To test the hypothesis that female marmoset sexual behavior is enhanced by flibanserin and diminished by 8-OH-DPAT, in order to evaluate the efficacy of serotonergic modulation of female sexual behavior in a pairmate social setting comparable to humans. Methods Sexual and social behavior were examined in 8 female marmoset monkeys receiving daily flibanserin (15mg/kg), 8-OH-DPAT (0.1 mg/kg) or corresponding vehicle for 15–16 weeks in a counterbalanced, within-subject design, while housed in long-term, stable male-female pairs. Main outcome measures Marmoset pairmate interactions, including sexual and social behavior, were scored during weeks 5–6 of daily flibanserin, 8-OH-DPAT or vehicle treatment. 24-h pharmacokinetic profiles of the drugs and their metabolites, as well as drug-induced acute symptoms of the 5-HT behavioral syndrome were also assessed. Results 2-way analysis of variance reveals that flibanserin-treated females attract more male sexual interest (p = .020) and trigger increased grooming (p = .001) between partners. In contrast, 8-OH-DPAT-treated females show increased rejection of male sexual advances (p = .024), a tendency for decreased male sexual interest (p = .080), and increased aggression with their male pairmates (p = .049). Conclusions While 8-OH-DPAT-treated female marmosets display decreased sexual receptivity and increased aggressive interactions with their male pairmates, flibanserin-treated female marmosets demonstrate increased affiliative behavior with their male pairmates. Such pro-affiliation attributes may underly flibanserin’s effectiveness in treating HSDD in women. PMID:22304661

To fight or mate? Hormonal control of sex recognition, male sexual behavior and aggression in the gecko lizard.

PubMed

Schořálková, Tereza; Kratochvíl, Lukáš; Kubička, Lukáš

2018-01-01

Squamate reptiles are a highly diversified vertebrate group with extensive variability in social behavior and sexual dimorphism. However, hormonal control of these traits has not previously been investigated in sufficient depth in many squamate lineages. Here, we studied the hormonal control of male sexual behavior, aggressiveness, copulatory organ (hemipenis) size and sex recognition in the gecko Paroedura picta, comparing ovariectomized females, ovariectomized females treated with exogenous dihydrotestosterone (DHT), ovariectomized females treated with exogenous testosterone (T), control females and males. The administration of both T and DHT led to the expression of male-typical sexual behavior in females. However, in contrast to T, increased circulating levels of DHT alone were not enough to initiate the full expression of male-typical offensive aggressive behavior and development of hemipenes in females. Ovariectomized females were as sexually attractive as control females, which does not support the need for the demasculinization of the cues used for sex recognition by ovarian hormones as suggested in other sauropsids. On the other hand, our results point to the masculinization of the sex recognition cues by male gonadal androgens. Previously, we also demonstrated that sexually dimorphic growth is controlled by ovarian hormones in P. picta. Overall, it appears that individual behavioral and morphological sexually-dimorphic traits are controlled by multiple endogenous pathways in this species. Variability in the endogenous control of particular traits could have permitted their disentangling during evolution and the occurrence of (semi)independent changes across squamate phylogeny. Copyright © 2017 Elsevier Inc. All rights reserved.

Rethinking Sexual Initiation: Pathways to Identity Formation among Gay and Bisexual Mexican Male Youth

PubMed Central

Carrillo, Héctor; Fontdevila, Jorge

2010-01-01

The topic of same-sex sexual initiation has generally remained understudied in the literature on sexual identity formation among sexual minority youth. This article analyzed the narratives of same-sex sexual initiation provided by 76 gay and bisexual Mexican immigrant men who participated in interviews for the Trayectos Study, an ethnographic study of sexuality and HIV risk. These participants were raised in a variety of locations throughout Mexico, where they also realized their same-sex attraction and initiated their sexual lives with men. We argue that Mexican male same-sex sexuality is characterized by three distinct patterns of sexual initiation-- one heavily-based on gender roles, one based on homosociality, and one based on object choice-- which inform the men’s interpretations regarding sexual roles, partner preferences, and sexual behaviors. We analyzed the social factors and forms of cultural/sexual socialization that lead sexual minority youth specifically to each of these three patterns of sexual initiation. Our findings confirm the importance of studying same-sex sexual initiation as a topic in its own right, particularly as a tool to gain a greater understanding of the diversity of same-sex sexual experiences and sexual identities within and among ethnic/cultural groups. PMID:20838869

Female guppies agree to differ: phenotypic and genetic variation in mate-choice behavior and the consequences for sexual selection.

PubMed

Brooks, R; Endler, J A

2001-08-01

Variation among females in mate choice may influence evolution by sexual selection. The genetic basis of this variation is of interest because the elaboration of mating preferences requires additive genetic variation in these traits. Here we measure the repeatability and heritability of two components of female choosiness (responsiveness and discrimination) and of female preference functions for the multiple ornaments borne by male guppies (Poecilia reticulata). We show that there is significant repeatable variation in both components of choosiness and in some preference functions but not in others. There appear to be several male ornaments that females find uniformly attractive and others for which females differ in preference. One consequence is that there is no universally attractive male phenotype. Only responsiveness shows significant additive genetic variation. Variation in responsiveness appears to mask variation in discrimination and some preference functions and may be the most biologically relevant source of phenotypic and genetic variation in mate-choice behavior. To test the potential evolutionary importance of the phenotypic variation in mate choice that we report, we estimated the opportunity for and the intensity of sexual selection under models of mate choice that excluded and that incorporated individual female variation. We then compared these estimates with estimates based on measured mating success. Incorporating individual variation in mate choice generally did not predict the outcome of sexual selection any better than models that ignored such variation.

Human vocal attractiveness as signaled by body size projection.

PubMed

Xu, Yi; Lee, Albert; Wu, Wing-Li; Liu, Xuan; Birkholz, Peter

2013-01-01

Voice, as a secondary sexual characteristic, is known to affect the perceived attractiveness of human individuals. But the underlying mechanism of vocal attractiveness has remained unclear. Here, we presented human listeners with acoustically altered natural sentences and fully synthetic sentences with systematically manipulated pitch, formants and voice quality based on a principle of body size projection reported for animal calls and emotional human vocal expressions. The results show that male listeners preferred a female voice that signals a small body size, with relatively high pitch, wide formant dispersion and breathy voice, while female listeners preferred a male voice that signals a large body size with low pitch and narrow formant dispersion. Interestingly, however, male vocal attractiveness was also enhanced by breathiness, which presumably softened the aggressiveness associated with a large body size. These results, together with the additional finding that the same vocal dimensions also affect emotion judgment, indicate that humans still employ a vocal interaction strategy used in animal calls despite the development of complex language.

Mapping female bodily features of attractiveness

PubMed Central

Bovet, Jeanne; Lao, Junpeng; Bartholomée, Océane; Caldara, Roberto; Raymond, Michel

2016-01-01

“Beauty is bought by judgment of the eye” (Shakespeare, Love’s Labour’s Lost), but the bodily features governing this critical biological choice are still debated. Eye movement studies have demonstrated that males sample coarse body regions expanding from the face, the breasts and the midriff, while making female attractiveness judgements with natural vision. However, the visual system ubiquitously extracts diagnostic extra-foveal information in natural conditions, thus the visual information actually used by men is still unknown. We thus used a parametric gaze-contingent design while males rated attractiveness of female front- and back-view bodies. Males used extra-foveal information when available. Critically, when bodily features were only visible through restricted apertures, fixations strongly shifted to the hips, to potentially extract hip-width and curvature, then the breast and face. Our hierarchical mapping suggests that the visual system primary uses hip information to compute the waist-to-hip ratio and the body mass index, the crucial factors in determining sexual attractiveness and mate selection. PMID:26791105

Sexual selection on cuticular hydrocarbons of male sagebrush crickets in the wild.

PubMed

Steiger, Sandra; Ower, Geoffrey D; Stökl, Johannes; Mitchell, Christopher; Hunt, John; Sakaluk, Scott K

2013-12-22

Cuticular hydrocarbons (CHCs) play an essential role in mate recognition in insects but the form and intensity of sexual selection on CHCs has only been evaluated in a handful of studies, and never in a natural population. We quantified sexual selection operating on CHCs in a wild population of sagebrush crickets, a species in which nuptial feeding by females imposes an unambiguous phenotypic marker on males. Multivariate selection analysis revealed a saddle-shaped fitness surface, suggesting a complex interplay between the total abundance of CHCs and specific CHC combinations in their influence on female choice. The fitness surface resulting from two axes of disruptive selection reflected a trade-off between short- and long-chained CHCs, suggesting that males may be sacrificing some level of desiccation resistance in favour of increased attractiveness. There was a significant correlation between male body size and total CHC abundance, suggesting that male CHCs provide females with a reliable cue for maximizing benefits obtained from males. Notwithstanding the conspicuousness of males' acoustic signals, our results suggest that selection imposed on males via female mating preferences may be far more complex than previously appreciated and operating in multiple sensory modalities.

Sociosexuality in women and preference for facial masculinization and somatotype in men.

PubMed

Provost, Meghan P; Kormos, Christine; Kosakoski, Graham; Quinsey, Vernon L

2006-06-01

Sociosexual orientation reflects individual differences in openness to short-term sexual relationships. We predicted that women with less restricted sociosexuality would be differentially attracted to highly masculinized male faces and bodies. In 2 studies, we investigated preference for male masculinization as a function of female sociosexuality. In Study 1, 40 female university students rated the attractiveness of pictures of male faces and somatotypes differing in masculinization level. All women preferred the faces with average levels of masculinity and the mesomorph somatotype; however, women with less restricted sociosexuality found the faces of men more attractive in general and showed relatively greater preference for masculinized bodies than did women with more restricted sociosexuality. In Study 2, 56 women met with 2 equally attractive male confederates, 1 highly masculinized and 1 less masculinized, in a "speed dating" scenario. After each date, women indicated their interest in each man for short-term and long-term relationships via questionnaire. In this more naturalistic context, sociosexuality was related to an increased interest for the more highly masculinized man in the context of short-term dating. Female sociosexuality appears to be related to preferences for higher levels of male masculinization.

Scent trailing by virgin females ofPseudococcm calceolariae.

PubMed

Rotundo, G; Tremblay, E

1981-01-01

Virgin females of the citrophilous mealybugPseudococcus calceolariae (Mask.) deposit scent marks as trails on the substrate on which they rest or move. These substances elicit attraction and sexual behavior by conspecific males. The same responses were obtained when males were bioassayed on extracts from filter paper disks on which females had rested. The significance of scent trailing in mealybugs is discussed.

Female song is widespread and ancestral in songbirds.

PubMed

Odom, Karan J; Hall, Michelle L; Riebel, Katharina; Omland, Kevin E; Langmore, Naomi E

2014-03-04

Bird song has historically been considered an almost exclusively male trait, an observation fundamental to the formulation of Darwin's theory of sexual selection. Like other male ornaments, song is used by male songbirds to attract females and compete with rivals. Thus, bird song has become a textbook example of the power of sexual selection to lead to extreme neurological and behavioural sex differences. Here we present an extensive survey and ancestral state reconstruction of female song across songbirds showing that female song is present in 71% of surveyed species including 32 families, and that females sang in the common ancestor of modern songbirds. Our results reverse classical assumptions about the evolution of song and sex differences in birds. The challenge now is to identify whether sexual selection alone or broader processes, such as social or natural selection, best explain the evolution of elaborate traits in both sexes.

Homophobic Name-Calling Among Secondary School Students and Its Implications for Mental Health

PubMed Central

Bos, Henny M. W.; Sandfort, Theo G. M.

2012-01-01

Although homophobic verbal victimization has been associated with negative mental health outcomes, little actually is known about its general prevalence and relationship to mental health among adolescents. In addition, the relationship of homophobic name-calling to mental health in gender non-conforming adolescents is not well understood. This study examined the relationship between homophobic verbal victimization and mental health in adolescents, accounting for their sexual orientation and level of gender non-conformity. Survey data was collected from 513 adolescents (ages 11–17) who attended eight schools in and around Amsterdam, the Netherlands; 56.7 % of the participating adolescents were female and 11.1 % reported same-sex attractions. As hypothesized, male adolescents and those with same-sex attractions were more likely to report victimization from homophobic name-calling than were their female and non-same-sex attracted peers. Contrary to expectations, homophobic name-calling was not independently associated with psychological distress after controlling for gender, sexual attractions, gender non-conformity, and other negative treatment by peers. The hypothesis that homophobic name-calling would be more strongly associated with psychological distress in male, same-sex attracted, and gender non-conforming adolescents was also not supported. The results suggest that same-sex attracted and gender non-conforming youth are particularly vulnerable to homophobic name-calling, in the Netherlands as in other contexts, but also that other forms of peer victimization may be more strongly related to mental health. PMID:23001719

Virtual Viewing Time: The Relationship between Presence and Sexual Interest in Androphilic and Gynephilic Men

PubMed Central

Fromberger, Peter; Meyer, Sabrina; Kempf, Christina; Jordan, Kirsten; Müller, Jürgen L.

2015-01-01

Virtual Reality (VR) has successfully been used in the research of human behavior for more than twenty years. The main advantage of VR is its capability to induce a high sense of presence. This results in emotions and behavior which are very close to those shown in real situations. In the context of sex research, only a few studies have used high-immersive VR so far. The ones that did can be found mostly in the field of forensic psychology. Nevertheless, the relationship between presence and sexual interest still remains unclear. The present study is the first to examine the advantages of high-immersive VR in comparison to a conventional standard desktop system regarding their capability to measure sexual interest. 25 gynephilic and 20 androphilic healthy men underwent three experimental conditions, which differed in their ability to induce a sense of presence. In each condition, participants were asked to rate ten male and ten female virtual human characters regarding their sexual attractiveness. Without their knowledge, the subjects’ viewing time was assessed throughout the rating. Subjects were then asked to rate the sense of presence they had experienced as well as their perceived realism of the characters. Results suggested that stereoscopic viewing can significantly enhance the subjective sexual attractiveness of sexually relevant characters. Furthermore, in all three conditions participants looked significantly longer at sexually relevant virtual characters than at sexually non-relevant ones. The high immersion condition provided the best discriminant validity. From a statistical point of view, however, the sense of presence had no significant influence on the discriminant validity of the viewing time task. The study showed that high-immersive virtual environments enhance realism ratings as well as ratings of sexual attractiveness of three-dimensional human stimuli in comparison to standard desktop systems. Results also show that viewing time seems to be influenced neither by sexual attractiveness nor by realism of stimuli. This indicates how important task specific mechanisms of the viewing time effect are. PMID:25992790

Self-perceived vs. actual physical attractiveness: Associations with depression as a function of sexual orientation.

PubMed

Ehlinger, Peter P; Blashill, Aaron J

2016-01-01

A commonly held belief about physical attractiveness is that attractive individuals are psychologically healthier than less attractive individuals (i.e., the "beauty is good" stereotype). To date, the data on this stereotype and its relationship with depression is limited, with a paucity of literature comparing subjective and objective appearance evaluations and depressive symptoms. Additionally, there is no known research on this relationship among sexual minorities (i.e., gay and bisexual individuals), a highly vulnerable population. The primary aims of the study were to assess the prediction of depression symptoms by subjective and objective appearance evaluation, and secondary aims were to assess the interaction of subjective and objective appearance with sexual orientation. Participants were 4882 American emerging adults (M age=22 years; 2253 males, 2629 females) taken from a U.S. nationally representative dataset (Add Health) Increased negative subjective appearance evaluation was associated with elevated rates of depressive symptoms (B=-.27, p<.001), while objective appearance evaluation was not significantly related to depressive symptoms. Sexual orientation significantly moderated the relationship between subjective appearance and depression (B=.19, p=.009), with a stronger positive association between negative appearance evaluation and depressive symptoms noted among sexual minority vs. heterosexual participants. Limitations include cross-sectional design and self-report nature of questionnaires. Findings suggest that the 'beauty is good' stereotype may not be valid in regard to depressive symptoms, and that subjective appearance evaluation is a robust predictor of depression, particularly for sexual minority individuals. Copyright © 2015 Elsevier B.V. All rights reserved.

Electroencephalographic activity during sexual behavior: a novel approach to the analysis of drug effects on arousal and motivation relevant for sexual dysfunctions.

PubMed

Hernández-González, Marisela; Guevara, Miguel Angel; Agmo, Anders

2014-06-01

The neurobiological bases of human sexual behavior are only partly understood. The etiology of most human sexual dysfunctions is not understood at all. Nevertheless, substantial progress has been made in the treatment of some male sexual disorders. The prime example should be erectile deficiency, where several efficient and safe treatments are available. Pharmacological treatment for premature ejaculation is also available, although it is still in an early stage. Disorders of sexual desire have attracted much attention when women are affected but far less so when men are concerned. Whereas animal models appropriate for testing treatments for problems with erection and premature ejaculation are available, it is questionable whether such models of the desire disorders have predictive validity. There seems to be many factors involved both in reduced and enhanced sexual desire, most of which are unknown. In this review we present some data suggesting that an electroencephalographic analysis of brain activity during exposure to sexually relevant stimuli in male rats and men and during execution of sexual behaviors in male rats may provide useful information. The effects of a commonly used drug, ethanol, on the electroencephalogram recorded during sexual events in rats and men are also described. Although this approach to the analysis of the central nervous activity associated with sexual desire, arousal and behavior is still in its infancy, the data obtained so far show a remarkable similarity between men and rats. This suggests that animal studies of electroencephalographic responses to drugs in sexual contexts may be useful for predicting effects in the human male. Copyright © 2014 Elsevier Inc. All rights reserved.

Neonatal agonism of ERβ impairs male reproductive behavior and attractiveness

PubMed Central

Sullivan, Alana W.; Hamilton, Peter; Patisaul, Heather B.

2011-01-01

The organization of the developing male rodent brain is profoundly influenced by endogenous steroids, most notably estrogen. This process may be disrupted by estrogenic endocrine disrupting compounds (EDCs) resulting in altered sex behavior and the capacity to attract a mate in adulthood. To better understand the relative role each estrogen receptor (ER) subtype (ERα and ERβ) plays in mediating these effects, we exposed male Long Evans rats to estradiol benzoate (EB, 10 μg), vehicle, or agonists specific for ERβ (DPN, 1 mg/kg) or ERα (PPT, 1 mg/kg) daily for the first four days of life, and then assessed adult male reproductive behavior and attractiveness via a partner preference paradigm. DPN had a greater adverse impact than PPT on reproductive behavior, suggesting a functional role for ERβ in the organization of these male-specific behaviors. Therefore the impact of neonatal ERβ agonism was further investigated by repeating the experiment using vehicle, EB and additional DPN doses (0.5 mg/kg, 1 mg/kg, and 2 mg/kg bw). Exposure to DPN suppressed male reproductive behavior and attractiveness in a dose dependent manner. Finally, males were exposed to EB or an environmentally relevant dose of genistein (GEN, 10 mg/kg), a naturally occurring xenoestrogen, which has a higher relative binding affinity for ERβ than ERα. Sexual performance was impaired by GEN but not attractiveness. In addition to suppressing reproductive behavior and attractiveness, EB exposure significantly lowered the testis to body weight ratio, and circulating testosterone levels. DPN and GEN exposure only impaired behavior, suggesting that disrupted androgen secretion does not underlie the impairment. PMID:21554883

Sexual Orientation Disparities in Human Papillomavirus Vaccination in a Longitudinal Cohort of U.S. Males and Females.

PubMed

Charlton, Brittany M; Reisner, Sari L; Agénor, Madina; Gordon, Allegra R; Sarda, Vishnudas; Austin, S Bryn

2017-06-01

This study sought to examine how human papillomavirus (HPV) vaccination may differ across sexual orientation groups (e.g., bisexuals compared to heterosexuals)-particularly in boys and men, about whom little is known. Data were from a prospective cohort of 10,663 U.S. females and males enrolled in the Growing Up Today Study followed from 1996 to 2014. Participants were aged 11-24 years when the vaccine was approved for females in 2006 and 14-27 years when approved for males in 2009. In addition to reporting sexual orientation identity/attractions, participants reported sex of lifetime sexual partners. Log-binominal models were used to examine HPV vaccination across sexual orientation groups. Among females, 56% received ≥1 dose. In contrast, 8% of males obtained ≥1 dose; HPV vaccination initiation was especially low among completely heterosexual males. After adjusting for potential confounders, completely heterosexual (risk ratio [RR]; 95% confidence interval [CI]: 0.45 [0.30-0.68]) and mostly heterosexual (RR; 95% CI: 0.44 [0.25-0.78]) males were half as likely to have received even a single dose compared to gay males. Compared to lesbians, no differences were observed for completely heterosexual or bisexual females, but mostly heterosexual females were 20% more likely to have received at least one dose. HPV vaccination rates in the U.S. are strikingly low and special attention is needed for boys and men, especially those who do not identify as gay. Vaccinating everyone, regardless of sex/gender and/or sexual orientation, will not only lower that individual's susceptibility but also decrease transmission to partners, females and/or males, to help eradicate HPV through herd immunity.

Auditory neural networks involved in attention modulation prefer biologically significant sounds and exhibit sexual dimorphism in anurans.

PubMed

Xue, Fei; Yue, Xizi; Fan, Yanzhu; Cui, Jianguo; Brauth, Steven E; Tang, Yezhong; Fang, Guangzhan

2018-03-09

Allocating attention to biologically relevant stimuli in a complex environment is critically important for survival and reproductive success. In humans, attention modulation is regulated by the frontal cortex, and is often reflected by changes in specific components of the event-related potential (ERP). Although brain networks for attention modulation have been widely studied in primates and avian species, little is known about attention modulation in amphibians. The present study aimed to investigate the attention modulation networks in an anuran species, the Emei music frog ( Babina daunchina ). Male music frogs produce advertisement calls from within underground nest burrows that modify the acoustic features of the calls, and both males and females prefer calls produced from inside burrows. We broadcast call stimuli to male and female music frogs while simultaneously recording electroencephalographic (EEG) signals from the telencephalon and mesencephalon. Granger causal connectivity analysis was used to elucidate functional brain networks within the time window of ERP components. The results show that calls produced from inside nests which are highly sexually attractive result in the strongest brain connections; both ascending and descending connections involving the left telencephalon were stronger in males while those in females were stronger with the right telencephalon. Our findings indicate that the frog brain allocates neural attention resources to highly attractive sounds within the window of early components of ERP, and that such processing is sexually dimorphic, presumably reflecting the different reproductive strategies of males and females. © 2018. Published by The Company of Biologists Ltd.

A Comparison of the Reproductive Output Among the Relatives of Samoan Androphilic Fa'afafine and Gynephilic Men.

PubMed

Semenyna, Scott W; Petterson, Lanna J; VanderLaan, Doug P; Vasey, Paul L

2017-01-01

The sexually antagonistic gene hypothesis (SAGH) for male androphilia posits that genes associated with androphilia (i.e., sexual attraction to adult males) will result in lowered reproduction when present in males, but increased reproduction when present in females. Findings derived from some Western European samples furnish support for the SAGH; however, results from studies conducted in other regions of the world have been more equivocal. Our previous research in Samoa indicated that the mothers as well as the maternal and paternal grandmothers of androphilic males (known locally as fa'afafine) exhibit elevated reproductive output when compared to the relatives of gynephilic men (i.e., males that are sexually attracted to adult females). The present replication study tested the SAGH in Samoa using a sample that was 122 % larger than the one previously studied by our group (VanderLaan, Forrester, Petterson, & Vasey, 2012). In line with the predictions of the SAGH, we hypothesized that the grandmothers, aunts, and mothers of fa'afafine would show elevated reproductive output compared to those of Samoan gynephilic men. Data were collected from 191 fa'afafine and 191 gynephilic men on the reproductive output of their paternal and maternal biological relatives (i.e., mothers, grandmothers, aunts, uncles). The mothers and maternal grandmothers of fa'afafine showed elevated reproductive output compared to those of gynephilic men. The paternal grandmother effect was not replicated. Although these results are consistent with the SAGH, a lack of difference in the reproductive output of aunts renders support for the SAGH in Samoa equivocal.

Caught in the act: pollination of sexually deceptive trap-flowers by fungus gnats in Pterostylis (Orchidaceae)

PubMed Central

Phillips, Ryan D.; Scaccabarozzi, Daniela; Retter, Bryony A.; Hayes, Christine; Brown, Graham R.; Dixon, Kingsley W.; Peakall, Rod

2014-01-01

Background and Aims Pterostylis is an Australasian terrestrial orchid genus of more than 400 species, most of which use a motile, touch-sensitive labellum to trap dipteran pollinators. Despite studies dating back to 1872, the mechanism of pollinator attraction has remained elusive. This study tested whether the fungus gnat-pollinated Pterostylis sanguinea secures pollination by sexual deception. Methods The literature was used to establish criteria for confirming sexual deception as a pollination strategy. Observations and video recordings allowed quantification of each step of the pollination process. Each floral visitor was sexed and DNA barcoding was used to evaluate the degree of pollinator specificity. Following observations that attraction to the flowers is by chemical cues, experimental dissection of flowers was used to determine the source of the sexual attractant and the effect of labellum orientation on sexual attraction. Fruit set was quantified for 19 populations to test for a relationship with plant density and population size. Key Results A single species of male gnat (Mycetophilidae) visited and pollinated the rewardless flowers. The gnats often showed probing copulatory behaviour on the labellum, leading to its triggering and the temporary entrapment of the gnat in the flower. Pollen deposition and removal occurred as the gnat escaped from the flower via the reproductive structures. The labellum was the sole source of the chemical attractant. Gnats always alighted on the labellum facing upwards, but when it was rotated 180 ° they attempted copulation less frequently. Pollination rate showed no relationship with orchid population size or plant density. Conclusions This study confirms for the first time that highly specific pollination by fungus gnats is achieved by sexual deception in Pterostylis. It is predicted that sexual deception will be widespread in the genus, although the diversity of floral forms suggests that other mechanisms may also operate. PMID:24366109

Ejaculate of sneaker males is pheromonally inconspicuous in the black goby, Gobius niger (Teleostei, Gobiidae).

PubMed

Locatello, L; Mazzoldi, C; Rasotto, M B

2002-11-01

The black goby, Gobius niger, shows alternative male mating tactics, i.e., parental and sneaker males. Males release a sexual pheromone that attracts females and stimulates aggressive displays in males. This pheromone is produced by the mesorchial gland, a structure well developed in parental males but markedly undeveloped in sneakers. We measured the behavioral response of parental males to the ejaculates of males performing different reproductive tactics. Parental males reacted to the ejaculate of other parental males, with stereotypic aggressive behaviors, but not to the ejaculate of sneakers; consequently sneaker male ejaculate appears to be pheromonally inconspicuous. Copyright 2002 Wiley-Liss, Inc.

Sexual selection on cuticular hydrocarbons of male sagebrush crickets in the wild

PubMed Central

Steiger, Sandra; Ower, Geoffrey D.; Stökl, Johannes; Mitchell, Christopher; Hunt, John; Sakaluk, Scott K.

2013-01-01

Cuticular hydrocarbons (CHCs) play an essential role in mate recognition in insects but the form and intensity of sexual selection on CHCs has only been evaluated in a handful of studies, and never in a natural population. We quantified sexual selection operating on CHCs in a wild population of sagebrush crickets, a species in which nuptial feeding by females imposes an unambiguous phenotypic marker on males. Multivariate selection analysis revealed a saddle-shaped fitness surface, suggesting a complex interplay between the total abundance of CHCs and specific CHC combinations in their influence on female choice. The fitness surface resulting from two axes of disruptive selection reflected a trade-off between short- and long-chained CHCs, suggesting that males may be sacrificing some level of desiccation resistance in favour of increased attractiveness. There was a significant correlation between male body size and total CHC abundance, suggesting that male CHCs provide females with a reliable cue for maximizing benefits obtained from males. Notwithstanding the conspicuousness of males’ acoustic signals, our results suggest that selection imposed on males via female mating preferences may be far more complex than previously appreciated and operating in multiple sensory modalities. PMID:24197415

Vaginal secretions increase the likelihood of intermale aggression in Syrian hamsters.

PubMed

Fischer, R B; Brown, P S

1993-08-01

Although sexually receptive female hamsters prefer dominant males as mating partners, it is not clear what role the female might play facilitating aggressive interactions among males that would lead to the establishment of a status relationship. The ability of vaginal odors to stimulate male aggression was examined by paring randomly chosen males in a neutral arena with vaginal odors either present or absent. Males exhibited significantly more aggression when tested in the scented arena. Vaginal odors are efficient broadcast signals serving to space females, attract males, and to stimulate aggressive interactions among the males while inhibiting aggression towards the female.

Replicated evolutionary divergence in the cuticular hydrocarbon profile of male crickets associated with the loss of song in the Hawaiian archipelago.

PubMed

Simmons, L W; Thomas, M L; Gray, B; Zuk, M

2014-10-01

Female choice based on male secondary sexual traits is well documented, although the extent to which this selection can drive an evolutionary divergence in male traits among populations is less clear. Male field crickets Teleogryllus oceanicus attract females using a calling song and once contacted switch to courtship song to persuade them to mate. These crickets also secrete onto their cuticle a cocktail of long-chained fatty acids or cuticular hydrocarbons (CHCs). Females choose among potential mates based on the structure of male acoustic signals and on the composition of male CHC profiles. Here, we utilize two naturally occurring mutations that have arisen independently on two Hawaiian islands and render the male silent to ask whether the evolutionary loss of acoustic signalling can drive an evolutionary divergence in the alternative signalling modality, male CHC profiles. QST -FST comparisons revealed strong patterns of CHC divergence among three populations of crickets on the islands of Hawaii, Oahu and Kauai. Contrasts between wild-type and flatwing males on the islands of Oahu and Kauai indicated that variation in male CHC profiles within populations is associated with the loss of acoustic signalling; flatwing males had a relatively low abundance of long-chained CHCs relative to the short-chained CHCs that females find attractive. Given their dual functions in desiccation resistance and sexual signalling, insect CHCs may be particularly important traits for reproductive isolation and ultimately speciation. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Does attractiveness influence condom use intentions in heterosexual men? An experimental study

PubMed Central

Eleftheriou, Anastasia; Bullock, Seth; Graham, Cynthia A; Stone, Nicole; Ingham, Roger

2016-01-01

Objectives Judgements of attractiveness have been shown to influence the character of social interactions. The present study sought to better understand the relationship between perceived attractiveness, perceived sexual health status and condom use intentions in a heterosexual male population. Setting The study employed an electronic questionnaire to collect all data, during face-to-face sessions. Participants 51 heterosexual, English-speaking men aged between 18 and 69 years. Outcome measures Men were asked to rate the attractiveness of 20 women on the basis of facial photographs, to estimate the likelihood that each woman had a sexually transmitted infection (STI) and to indicate their willingness to have sex with or without a condom with each woman. Results The more attractive a woman was judged to be on average, the more likely participants would be willing to have sex with her (p<0.0001) and the less likely they were to intend to use a condom during sex (p<0.0001). Multivariate analysis revealed that higher condom use intentions towards a particular woman were associated with lower ratings of her attractiveness (p<0.0005), higher ratings of her STI likelihood (p<0.0001), the participant being in an exclusive relationship (p=0.002), having a less satisfactory sex life (p=0.015), lower age (p=0.001), higher number of sexual partners (p=0.001), higher age at first intercourse (p=0.002), higher rates of condomless sex in the last 12 months (p<0.043) and lower confidence in their ability to assess whether or not a woman had an STI (p=0.001). The more attractive a participant judged himself to be, the more he believed that other men like him would engage in condomless sex (p=0.001) and the less likely he was to intend to use a condom himself (p=0.02). Conclusions Male perceptions of attractiveness influence their condom use intentions; such risk biases could profitably be discussed during sex education sessions and in condom use promotion interventions. PMID:27315834

Exposure to monocrotophos pesticide during sexual development causes the feminization/demasculinization of the reproductive traits and a reduction in the reproductive success of male guppies (Poecilia reticulata)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tian, Hua; Li, Yun; Wang, Wei

Monocrotophos is a highly toxic organophosphorus pesticide that has been confirmed to be an endocrine‐disrupting chemical. To evaluate the influence of this pollutant on the reproductive system of male fish, we studied the sex steroid levels, reproductive traits, sex ratio, and reproductive success in male guppies (Poecilia reticulata) exposed to 40% monocrotophos pesticide at the nominal concentrations of 0.01, 0.10, and 1.00 mg/L for 90 days from birth to adulthood in a semi‐static exposure system. Radioimmunoassay and western blot analyses demonstrated that the long‐term exposure to monocrotophos pesticide during the sexual development of male guppies caused a significant increase inmore » 17β‐estradiol levels and consequently induced vitellogenin synthesis, suggesting the feminization of the males. Monocrotophos pesticide also caused a significant decrease in testosterone levels, which consequently inhibited testis growth and reduced the sperm count and the area and intensity of their sexually attractive orange spots, which collectively indicated the significant demasculinization of the male sexual characteristics. Furthermore, these changes in the sexual characteristics at the cellular and organ levels translated into ecologically important effects on the reproductive success at the individual level, as measured by a decrease in offspring production and survival rate. The present study provides the first evidence that monocrotophos pesticide can cause severe reproductive abnormalities in fish due to its endocrine‐disrupting action. -- Highlights: ► Monocrotophos pesticide caused an increase in 17β‐estradiol levels of male guppies. ► Monocrotophos pesticide induced vitellogenin synthesis of male guppies. ► Monocrotophos pesticide caused a decrease in testosterone levels of male guppies. ► Monocrotophos pesticide caused demasculinization of male sexual characteristics. ► Monocrotophos pesticide caused a reduction in reproductive success of male guppies.« less

Reduction of dopamine level enhances the attractiveness of male Drosophila to other males.

PubMed

Liu, Tong; Dartevelle, Laurence; Yuan, Chunyan; Wei, Hongping; Wang, Ying; Ferveur, Jean-François; Guo, Aike

2009-01-01

Dopamine is an important neuromodulator in animals and its roles in mammalian sexual behavior are extensively studied. Drosophila as a useful model system is widely used in many fields of biological studies. It has been reported that dopamine reduction can affect female receptivity in Drosophila and leave male-female courtship behavior unaffected. Here, we used genetic and pharmacological approaches to decrease the dopamine level in dopaminergic cells in Drosophila, and investigated the consequence of this manipulation on male homosexual courtship behavior. We find that reduction of dopamine level can induce Drosophila male-male courtship behavior, and that this behavior is mainly due to the increased male attractiveness or decreased aversiveness towards other males, but not to their enhanced propensity to court other males. Chemical signal input probably plays a crucial role in the male-male courtship induced by the courtees with reduction of dopamine. Our finding provides insight into the relationship between the dopamine reduction and male-male courtship behavior, and hints dopamine level is important for controlling Drosophila courtship behavior.

Reduction of Dopamine Level Enhances the Attractiveness of Male Drosophila to Other Males

PubMed Central

Liu, Tong; Dartevelle, Laurence; Yuan, Chunyan; Wei, Hongping; Wang, Ying; Ferveur, Jean-François; Guo, Aike

2009-01-01

Dopamine is an important neuromodulator in animals and its roles in mammalian sexual behavior are extensively studied. Drosophila as a useful model system is widely used in many fields of biological studies. It has been reported that dopamine reduction can affect female receptivity in Drosophila and leave male-female courtship behavior unaffected. Here, we used genetic and pharmacological approaches to decrease the dopamine level in dopaminergic cells in Drosophila, and investigated the consequence of this manipulation on male homosexual courtship behavior. We find that reduction of dopamine level can induce Drosophila male-male courtship behavior, and that this behavior is mainly due to the increased male attractiveness or decreased aversiveness towards other males, but not to their enhanced propensity to court other males. Chemical signal input probably plays a crucial role in the male-male courtship induced by the courtees with reduction of dopamine. Our finding provides insight into the relationship between the dopamine reduction and male-male courtship behavior, and hints dopamine level is important for controlling Drosophila courtship behavior. PMID:19238209

Sexual selection in the squirrel treefrog Hyla squirella: the role of multimodal cue assessment in female choice

USGS Publications Warehouse

Taylor, Ryan C.; Buchanan, Bryant W.; Doherty, Jessie L.

2007-01-01

Anuran amphibians have provided an excellent system for the study of animal communication and sexual selection. Studies of female mate choice in anurans, however, have focused almost exclusively on the role of auditory signals. In this study, we examined the effect of both auditory and visual cues on female choice in the squirrel treefrog. Our experiments used a two-choice protocol in which we varied male vocalization properties, visual cues, or both, to assess female preferences for the different cues. Females discriminated against high-frequency calls and expressed a strong preference for calls that contained more energy per unit time (faster call rate). Females expressed a preference for the visual stimulus of a model of a calling male when call properties at the two speakers were held the same. They also showed a significant attraction to a model possessing a relatively large lateral body stripe. These data indicate that visual cues do play a role in mate attraction in this nocturnal frog species. Furthermore, this study adds to a growing body of evidence that suggests that multimodal signals play an important role in sexual selection.

Cuticular hydrocarbons as sex pheromone of the bee Colletes cunicularius and the key to its mimicry by the sexually deceptive orchid, Ophrys exaltata.

PubMed

Mant, Jim; Brändli, Christoph; Vereecken, Nicolas J; Schulz, Claudia M; Francke, Wittko; Schiestl, Florian P

2005-08-01

Male Colletes cunicularius bees pollinate the orchid, Ophrys exaltata, after being sexually deceived by the orchid's odor-mimicry of the female bee's sex pheromone. We detected biologically active volatiles of C. cunicularius by using gas chromatographic-electroantennographic detection (GC-EAD) with simultaneous flame ionization detection. After identification of the target compounds by coupled gas chromatography mass spectrometry (GC-MS), we performed behavioral tests using synthetic blends of the active components. We detected 22 EAD active compounds in cuticular extracts of C. cunicularius females. Blends of straight chain, odd-numbered alkanes and (Z)-7-alkenes with 21-29 carbon atoms constituted the major biologically active compounds. Alkenes were the key compounds releasing mating behavior, especially those with (Z)-7 unsaturation. Comparison of patterns of bee volatiles with those of O. exaltata subsp. archipelagi revealed that all EAD-active compounds were also found in extracts of orchid labella. Previous studies of the mating behavior in C. cunicularius showed linalool to be an important attractant for patrolling males. We confirmed this with synthetic linalool but found that it rarely elicited copulatory behavior, in accordance with previous studies. A blend of active cuticular compounds with linalool elicited both attraction and copulation behavior in patrolling males. Thus, linalool appears to function as a long-range attractant, whereas cuticular hydrocarbons are necessary for inducing short-range mating behavior.

Men and infant feeding: perceptions of embarrassment, sexuality, and social conduct in white low-income British men.

PubMed

Henderson, Lesley; McMillan, Brian; Green, Josephine M; Renfrew, Mary J

2011-03-01

The views of fathers have been shown to be important determinants of infant feeding decisions, but men's perceptions of breastfeeding and formula feeding are rarely explored. Our objectives were to address this gap and examine cultural associations and beliefs concerning infant feeding practices among men. Five focus groups were conducted with low-income men (n = 28) living in areas of social deprivation in Leeds, northeast of England, and low-income areas of Glasgow, west of Scotland. Participants were white British men, aged between 16 and 45 years, and included fathers, expectant fathers, and potential fathers. Overarching themes concerning sexuality, embarrassment, and social conduct were identified across all groups. Participants perceived breastfeeding as "natural" but problematic, whereas formula feeding was mainly considered as convenient and safe. Participants without direct experience of breastfeeding assumed that it involved excessive public exposure and attracted unwanted male attention. Underpinning these fears were strong cultural associations between breasts and sexuality and anxieties concerning appropriate gender roles. In some communities few opportunities may occur to witness breastfeeding, and thus existing fears concerning the activity as attracting predatory male attention remain unchallenged. Perceptions of breastfeeding as a sexual activity and the dominant mass media emphasis on breasts as a sexual site may present additional obstacles to breastfeeding. Antenatal or perinatal education with men should address not only practical issues but also provide advice on tackling problems generated by wider sociocultural issues of sexuality and masculinity. © 2010, Copyright the Authors. Journal compilation © 2010, Wiley Periodicals, Inc.

Is Male Androphilia a Context-Dependent Cross-Cultural Universal?

PubMed

Hames, Raymond; Garfield, Zachary; Garfield, Melissa

2017-01-01

The cross-cultural ethnographic literature has traditionally used the label male "homosexuality" to describe sexual relationships between biological males without considering whether or not the concept encompasses primary sexual attraction to adult males. Although male androphilia seems to be found in all national populations, its universal existence in tribal populations has been questioned. Our goal is to review previous cross-cultural classifications and surveys of male same sex behavior to present a system that does justice to its varied expressions, especially as it is informed by contemporary sexuality research. Previous comparative research does not effectively distinguish male same sex behavior from male androphilia. Using the standard cross-cultural sample (SCCS) as a sampling frame and the ethnographic sources in the human relations area files and elsewhere, we present distributional data on various forms of male same sex behavior. The SCCS is useful because it is designed to be representative of all historically known social formations and the sample is designed to reduce similarities as a consequence of common descent or historical origin as well as reduce the probability of diffusion of sociocultural practices from one culture to another. Our results show that male same sex behavior as well as male androphilia is much more common than previously estimated in the SCCS. With our findings, we make an argument that male androphilia is a context-dependent cross-cultural universal.

Colour mimicry and sexual deception by Tongue orchids ( Cryptostylis)

NASA Astrophysics Data System (ADS)

Gaskett, A. C.; Herberstein, M. E.

2010-01-01

Typically, floral colour attracts pollinators by advertising rewards such as nectar, but how does colour function when pollinators are deceived, unrewarded, and may even suffer fitness costs? Sexually deceptive orchids are pollinated only by male insects fooled into mating with orchid flowers and inadvertently transferring orchid pollinia. Over long distances, sexually deceptive orchids lure pollinators with counterfeit insect sex pheromones, but close-range deception with colour mimicry is a tantalising possibility. Here, for the first time, we analyse the colours of four sexually deceptive Cryptostylis orchid species and the female wasp they mimic ( Lissopimpla excelsa, Ichneumonidae), from the perspective of the orchids’ single, shared pollinator, male Lissopimpla excelsa. Despite appearing different to humans, the colours of the orchids and female wasps were effectively identical when mapped into a hymenopteran hexagonal colour space. The orchids and wasps reflected predominantly red-orange wavelengths, but UV was also reflected by raised bumps on two orchid species and by female wasp wings. The orchids’ bright yellow pollinia contrasted significantly with their overall red colour. Orchid deception may therefore involve accurate and species-specific mimicry of wavelengths reflected by female wasps, and potentially, exploitation of insects’ innate attraction to UV and yellow wavelengths. In general, mimicry may be facilitated by exploiting visual vulnerabilities and evolve more readily at the peripheries of sensory perception. Many sexually deceptive orchids are predominantly red, green or white: colours that are all potentially difficult for hymenoptera to detect or distinguish from the background.

Colour mimicry and sexual deception by Tongue orchids (Cryptostylis).

PubMed

Gaskett, A C; Herberstein, M E

2010-01-01

Typically, floral colour attracts pollinators by advertising rewards such as nectar, but how does colour function when pollinators are deceived, unrewarded, and may even suffer fitness costs? Sexually deceptive orchids are pollinated only by male insects fooled into mating with orchid flowers and inadvertently transferring orchid pollinia. Over long distances, sexually deceptive orchids lure pollinators with counterfeit insect sex pheromones, but close-range deception with colour mimicry is a tantalising possibility. Here, for the first time, we analyse the colours of four sexually deceptive Cryptostylis orchid species and the female wasp they mimic (Lissopimpla excelsa, Ichneumonidae), from the perspective of the orchids' single, shared pollinator, male Lissopimpla excelsa. Despite appearing different to humans, the colours of the orchids and female wasps were effectively identical when mapped into a hymenopteran hexagonal colour space. The orchids and wasps reflected predominantly red-orange wavelengths, but UV was also reflected by raised bumps on two orchid species and by female wasp wings. The orchids' bright yellow pollinia contrasted significantly with their overall red colour. Orchid deception may therefore involve accurate and species-specific mimicry of wavelengths reflected by female wasps, and potentially, exploitation of insects' innate attraction to UV and yellow wavelengths. In general, mimicry may be facilitated by exploiting visual vulnerabilities and evolve more readily at the peripheries of sensory perception. Many sexually deceptive orchids are predominantly red, green or white: colours that are all potentially difficult for hymenoptera to detect or distinguish from the background.

[The participation of vaginal bacteria in Phodopus campbelli in the chemical communication between male and female].

PubMed

Sokolov, V E; Ushakova, N A; Surov, A V; Telitsyna, A Iu

1994-01-01

Phodopus campbelli commonly occurs in dry steppe and semidesert zone of south Siberia, Mongolia and China. Using radiotelemetry we found that a male has to cover about 2 km from his burrow to encounter a receptive female. Female in estrus marks a small area around its burrow by vaginal smear. Experiments were carried out in laboratory to discover the nature of this strong signal. In a "open field" area four boxes within stimuli we recorded the time complemented spent by males near boxes to study the attractive effect of intact receptive female, germ culture of vaginal smear and artificial mixed culture of bacteria which were found in the vaginal smear of Ph. campbelli receptive female. Males (n = 15) spent significantly more time near the boxes with female in estrus or day before estrus as compared with two other days of cycle. Germ culture from vaginal smear sampled on the estrus day was more attractive to males on 6th day than on the 2, -3, -5, -7, -8--or 9th days of cultivation, pure culture or germ culture sampled on anestrus. Mixed culture, which simulated the proportion of predominant bacteria in the estrus vaginal smear, was significantly more attractive for males on the 3rd day of cultivation. Thus sexual attractant of Ph. campbelli could be produced by some bacteria located in the vagina in estrus and it takes a couple of days of cultivation for maximum attractive effect.

Perceptual fluency and judgments of vocal aesthetics and stereotypicality.

PubMed

Babel, Molly; McGuire, Grant

2015-05-01

Research has shown that processing dynamics on the perceiver's end determine aesthetic pleasure. Specifically, typical objects, which are processed more fluently, are perceived as more attractive. We extend this notion of perceptual fluency to judgments of vocal aesthetics. Vocal attractiveness has traditionally been examined with respect to sexual dimorphism and the apparent size of a talker, as reconstructed from the acoustic signal, despite evidence that gender-specific speech patterns are learned social behaviors. In this study, we report on a series of three experiments using 60 voices (30 females) to compare the relationship between judgments of vocal attractiveness, stereotypicality, and gender categorization fluency. Our results indicate that attractiveness and stereotypicality are highly correlated for female and male voices. Stereotypicality and categorization fluency were also correlated for male voices, but not female voices. Crucially, stereotypicality and categorization fluency interacted to predict attractiveness, suggesting the role of perceptual fluency is present, but nuanced, in judgments of human voices. © 2014 Cognitive Science Society, Inc.

The importance of feeling sexually attractive: Can it predict an individual's experience of their sexuality and sexual relationships across gender and sexual orientation?

PubMed

Amos, Natalie; McCabe, Marita

2017-10-01

Limited research exists on the implications of feeling sexually attractive for various aspects of sexuality and sexual relationships. This article examined associations between self-perceived sexual attractiveness and sexual esteem, sexual satisfaction and amount of sexual experience, among both men and women who identified as heterosexual (n = 1017), gay or lesbian (n = 1225) or bisexual (n = 651). Results of the study demonstrated that positive self-perceptions of sexual attractiveness predicted greater sexual esteem, greater sexual satisfaction, a higher frequency of sexual activity with others and a larger number of sexual partners among both men and women who identified as heterosexual, gay, lesbian or bisexual. The findings suggest that feeling sexually attractive may have implications for how an individual experiences their sexuality and sexual relationships regardless of their gender or sexual orientation. The importance of considering an individual's self-perceptions of sexual attractiveness when they present with concerns related to their sexual experiences or relationships, and the potential benefits of educational and therapeutic interventions designed to enhance self-perceptions of sexual attractiveness are discussed. © 2015 International Union of Psychological Science.

Identification and characterization of adolescents' sexual boundaries.

PubMed

Wolf, Hilary T; Morrell, Holly E R; Halpern-Felsher, Bonnie L

2013-07-01

Adolescents' decisions to have sex may be based on a priori boundaries placed on sex. This study addresses: (1) to what extent adolescents set vaginal sexual boundaries; (2) the types of sexual boundaries most and least likely to be endorsed; and (3) to what extent sexual boundaries vary by sex, race/ethnicity, and sexual experience. A cross-sectional study of 518 students attending 10th grade. Survey measures queried about demographics, ever having sex, and existence of sexual boundaries (e.g., being in love, having an attractive partner) that must be in place before having vaginal sex. The most frequently endorsed boundaries were maturity, commitment, trust, love, and marriage. These boundaries were more frequently endorsed than having a safer-sex method. Compared with females, males were more likely to choose boundaries based on partner attractiveness (p < .001) and avoiding trouble (p < .04). Compared with Asians and Pacific Islanders, whites were more likely to endorse wanting to be a certain age to have sex (p < .01 and p < .05, respectively); Asians and Pacific Islanders were more likely to choose sexual boundaries based on marriage (p's < .05). Adolescents who were sexually experienced were more likely than inexperienced adolescents to endorse boundaries related to relationship characteristics and partner attractiveness (OR = 2.5), and less likely to endorse boundaries related to feeling mature (OR = .34) and waiting until marriage (OR = .34). Identifying adolescents' sexual boundaries should help healthcare professionals better understand under what circumstances adolescents are more or less likely to have sex; and this information should ultimately inform the development of new interventions. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Sexual Orientation Discordance and Young Adult Mental Health.

PubMed

Lourie, Michael A; Needham, Belinda L

2017-05-01

During the course of sexual development, many people experience dissonance between dimensions of sexual orientation, including attraction, behavior, and identity. This study assesses the relationship between sexual orientation discordance and mental health. Data were obtained from the National Longitudinal Study of Adolescent to Adult Health (n = 8,915; female = 54.62 %; non-Hispanic black = 18.83 %, Hispanic = 14.91 %, other race (non-white) = 10.79 %). Multivariable linear regression evaluated the correlation between sexual orientation discordance and perceived stress and depressive symptomatology. Models were stratified by sex and sexual identity. Among self-identified heterosexual females and mostly heterosexual males, sexual orientation discordance predicted significantly increased depressive symptomatology. No other subpopulation demonstrated a significant correlation between sexual orientation discordance and depressive symptomatology or perceived stress. The association between sexual orientation discordance and depressive symptomatology suggests a link between sexuality, self-concept, and mental health.

Making sense of sexual orientation measures: findings from a cognitive processing study with adolescents on health survey questions.

PubMed

Austin, S Bryn; Conron, Kerith; Patel, Aarti; Freedner, Naomi

2007-01-01

To carry out a study using cognitive processing interview methods to explore ways in which adolescents understand sexual orientation questions currently used on epidemiologic surveys. In-depth, individual interviews were conducted to probe cognitive processes involved in answering four self-report survey questions assessing sexual identity, sexual attraction, and sex of sexual partners.A semi-structured interview guide was used to explore variation in question interpretation, information retrieval patterns and problems, item clarity, valence of reactions to items (positive, negative, neutral), respondent burden, and perceived threat associated with the measures. Thirty adolescents aged 15 to 21 of diverse sexual orientations and race/ethnicities participated in the study, including female, male, and transgender youth. A question on sexual attraction was the most consistently understood and thus was easy for nearly all youth to answer. In contrast, a measure of sexual identity with options heterosexual, bisexual, gay/lesbian, and unsure was the most difficult to answer. Most preferred a sexual identity item that also provided the intermediate options mostly heterosexual and mostly homosexual, which many said reflected their experience of feeling between categories. Participants had varying and inconsistent interpretations of sexual behavior terms, such as sex and sexual intercourse, used in assessing the sex of sexual partners. Differences in understanding could affect interpretation of survey data in important ways. Development of valid measures of sexual orientation will be essential to better monitor health disparities.

Asexuality: a mixed-methods approach.

PubMed

Brotto, Lori A; Knudson, Gail; Inskip, Jess; Rhodes, Katherine; Erskine, Yvonne

2010-06-01

Current definitions of asexuality focus on sexual attraction, sexual behavior, and lack of sexual orientation or sexual excitation; however, the extent to which these definitions are accepted by self-identified asexuals is unknown. The goal of Study 1 was to examine relationship characteristics, frequency of sexual behaviors, sexual difficulties and distress, psychopathology, interpersonal functioning, and alexithymia in 187 asexuals recruited from the Asexuality Visibility and Education Network (AVEN). Asexual men (n = 54) and women (n = 133) completed validated questionnaires online. Sexual response was lower than normative data and was not experienced as distressing, and masturbation frequency in males was similar to available data for sexual men. Social withdrawal was the most elevated personality subscale; however, interpersonal functioning was in the normal range. Alexithymia was elevated in 12%. Social desirability was also in the normal range. Study 2 was designed to expand upon these quantitative findings with 15 asexuals from Study 1 through in-depth telephone interviews. The findings suggest that asexuality is best conceptualized as a lack of sexual attraction; however, asexuals varied greatly in their experience of sexual response and behavior. Asexuals partnered with sexuals acknowledged having to "negotiate" sexual activity. There were not higher rates of psychopathology among asexuals; however, a subset might fit the criteria for Schizoid Personality Disorder. There was also strong opposition to viewing asexuality as an extreme case of sexual desire disorder. Finally, asexuals were very motivated to liaise with sex researchers to further the scientific study of asexuality.

Role of the vomeronasal system in intersexual attraction in female mice.

PubMed

Martínez-Ricós, J; Agustín-Pavón, C; Lanuza, E; Martínez-García, F

2008-05-02

Although it is generally accepted that rodents' sociosexual behavior relies mainly on chemosignals, the specific roles played by the vomeronasal and olfactory systems in detecting these signals are presently unclear. This work reports the results of three experiments aimed at clarifying the role of the vomeronasal system on gender recognition and intersexual attraction, by analyzing the effects of lesions of the accessory olfactory bulbs (AOB) in chemically naïve female mice. The first experiment demonstrates that lesions of the AOB abolish the preference that females show for male-soiled bedding in tests in which the females can contact the bedding, thus having access to both volatile and involatile male chemosignals. The second experiment shows that airborne male-derived chemosignals are not attractive to intact, chemically naïve females but tend to be preferentially explored by females whose AOB has been lesioned. However, repeated exposure to male-soiled bedding has opposite effects in sham-operated and AOB-lesioned female mice. Whereas after this experience sham-operated females show an (acquired) attraction toward male airborne chemosignals, in AOB-lesioned females the same experience makes male-derived volatiles aversive. Finally, in the third experiment we have confirmed that our AOB-lesioned females are able to detect urine-borne male odorants, as well as to discriminate them from the synthetic terpene geraniol. These findings strongly suggest that in mice, the involatile male sexual pheromone that is intrinsically attractive is detected by the vomeronasal system of the females. In addition, the repeated experience of females with male-soiled bedding would probably allow the association of this pheromone, acting as unconditioned stimulus, with olfactory stimuli (odorants) that therefore would become conditioned attractors to the females.

BIRTH ORDER AND ANDROPHILIC MALE-TO-FEMALE TRANSSEXUALISM IN BRAZIL.

PubMed

Vanderlaan, Doug P; Blanchard, Ray; Zucker, Kenneth J; Massuda, Raffael; Fontanari, Anna Martha Vaitses; Borba, André Oliveira; Costa, Angelo Bradelli; Schneider, Maiko Abel; Mueller, Andressa; Soll, Bianca Machado Borba; Schwarz, Karine; Da Silva, Dhiordan Cardoso; Lobato, Maria Inês Rodrigues

2017-07-01

Previous research has indicated that biological older brothers increase the odds of androphilia in males. This finding has been termed the fraternal birth order effect. The maternal immune hypothesis suggests that this effect reflects the progressive immunization of some mothers to male-specific antigens involved in fetal male brain masculinization. Exposure to these antigens, as a result of carrying earlier-born sons, is hypothesized to produce maternal immune responses towards later-born sons, thus leading to female-typical neural development of brain regions underlying sexual orientation. Because this hypothesis posits mechanisms that have the potential to be active in any situation where a mother gestates repeated male fetuses, a key prediction is that the fraternal birth order effect should be observable in diverse populations. The present study assessed the association between sexual orientation and birth order in androphilic male-to-female transsexuals in Brazil, a previously unexamined population. Male-to-female transsexuals who reported attraction to males were recruited from a specialty gender identity service in southern Brazil (n=118) and a comparison group of gynephilic non-transsexual men (n=143) was recruited at the same hospital. Logistic regression showed that the transsexual group had significantly more older brothers and other siblings. These effects were independent of one another and consistent with previous studies of birth order and male sexual orientation. The presence of the fraternal birth order effect in the present sample provides further evidence of the ubiquity of this effect and, therefore, lends support to the maternal immune hypothesis as an explanation of androphilic sexual orientation in some male-to-female transsexuals.

Transcriptome and proteome data reveal candidate genes for pollinator attraction in sexually deceptive orchids.

PubMed

Sedeek, Khalid E M; Qi, Weihong; Schauer, Monica A; Gupta, Alok K; Poveda, Lucy; Xu, Shuqing; Liu, Zhong-Jian; Grossniklaus, Ueli; Schiestl, Florian P; Schlüter, Philipp M

2013-01-01

Sexually deceptive orchids of the genus Ophrys mimic the mating signals of their pollinator females to attract males as pollinators. This mode of pollination is highly specific and leads to strong reproductive isolation between species. This study aims to identify candidate genes responsible for pollinator attraction and reproductive isolation between three closely related species, O. exaltata, O. sphegodes and O. garganica. Floral traits such as odour, colour and morphology are necessary for successful pollinator attraction. In particular, different odour hydrocarbon profiles have been linked to differences in specific pollinator attraction among these species. Therefore, the identification of genes involved in these traits is important for understanding the molecular basis of pollinator attraction by sexually deceptive orchids. We have created floral reference transcriptomes and proteomes for these three Ophrys species using a combination of next-generation sequencing (454 and Solexa), Sanger sequencing, and shotgun proteomics (tandem mass spectrometry). In total, 121 917 unique transcripts and 3531 proteins were identified. This represents the first orchid proteome and transcriptome from the orchid subfamily Orchidoideae. Proteome data revealed proteins corresponding to 2644 transcripts and 887 proteins not observed in the transcriptome. Candidate genes for hydrocarbon and anthocyanin biosynthesis were represented by 156 and 61 unique transcripts in 20 and 7 genes classes, respectively. Moreover, transcription factors putatively involved in the regulation of flower odour, colour and morphology were annotated, including Myb, MADS and TCP factors. Our comprehensive data set generated by combining transcriptome and proteome technologies allowed identification of candidate genes for pollinator attraction and reproductive isolation among sexually deceptive orchids. This includes genes for hydrocarbon and anthocyanin biosynthesis and regulation, and the development of floral morphology. These data will serve as an invaluable resource for research in orchid floral biology, enabling studies into the molecular mechanisms of pollinator attraction and speciation.

Transcriptome and Proteome Data Reveal Candidate Genes for Pollinator Attraction in Sexually Deceptive Orchids

PubMed Central

Sedeek, Khalid E. M.; Qi, Weihong; Schauer, Monica A.; Gupta, Alok K.; Poveda, Lucy; Xu, Shuqing; Liu, Zhong-Jian; Grossniklaus, Ueli; Schiestl, Florian P.; Schlüter, Philipp M.

2013-01-01

Background Sexually deceptive orchids of the genus Ophrys mimic the mating signals of their pollinator females to attract males as pollinators. This mode of pollination is highly specific and leads to strong reproductive isolation between species. This study aims to identify candidate genes responsible for pollinator attraction and reproductive isolation between three closely related species, O. exaltata, O. sphegodes and O. garganica. Floral traits such as odour, colour and morphology are necessary for successful pollinator attraction. In particular, different odour hydrocarbon profiles have been linked to differences in specific pollinator attraction among these species. Therefore, the identification of genes involved in these traits is important for understanding the molecular basis of pollinator attraction by sexually deceptive orchids. Results We have created floral reference transcriptomes and proteomes for these three Ophrys species using a combination of next-generation sequencing (454 and Solexa), Sanger sequencing, and shotgun proteomics (tandem mass spectrometry). In total, 121 917 unique transcripts and 3531 proteins were identified. This represents the first orchid proteome and transcriptome from the orchid subfamily Orchidoideae. Proteome data revealed proteins corresponding to 2644 transcripts and 887 proteins not observed in the transcriptome. Candidate genes for hydrocarbon and anthocyanin biosynthesis were represented by 156 and 61 unique transcripts in 20 and 7 genes classes, respectively. Moreover, transcription factors putatively involved in the regulation of flower odour, colour and morphology were annotated, including Myb, MADS and TCP factors. Conclusion Our comprehensive data set generated by combining transcriptome and proteome technologies allowed identification of candidate genes for pollinator attraction and reproductive isolation among sexually deceptive orchids. This includes genes for hydrocarbon and anthocyanin biosynthesis and regulation, and the development of floral morphology. These data will serve as an invaluable resource for research in orchid floral biology, enabling studies into the molecular mechanisms of pollinator attraction and speciation. PMID:23734209

How parasitoid females produce sexy sons: a causal link between oviposition preference, dietary lipids and mate choice in Nasonia

PubMed Central

Blaul, Birgit; Ruther, Joachim

2011-01-01

Sexual selection theory predicts that phenotypic traits used to choose a mate should reflect honestly the quality of the sender and thus, are often costly. Physiological costs arise if a signal depends on limited nutritional resources. Hence, the nutritional condition of an organism should determine both its quality as a potential mate and its ability to advertise this quality to the choosing sex. In insects, the quality of the offspring's nutrition is often determined by the ovipositing female. A causal connection, however, between the oviposition decisions of the mother and the mating chances of her offspring has never been shown. Here, we demonstrate that females of the parasitic wasp Nasonia vitripennis prefer those hosts for oviposition that have been experimentally enriched in linoleic acid (LA). We show by 13C-labelling that LA from the host diet is a precursor of the male sex pheromone. Consequently, males from LA-rich hosts produce and release higher amounts of the pheromone and attract more virgin females than males from LA-poor hosts. Finally, males from LA-rich hosts possess three times as many spermatozoa as those from LA-poor hosts. Hence, females making the right oviposition decisions may increase both the fertility and the sexual attractiveness of their sons. PMID:21429922

How parasitoid females produce sexy sons: a causal link between oviposition preference, dietary lipids and mate choice in Nasonia.

PubMed

Blaul, Birgit; Ruther, Joachim

2011-11-07

Sexual selection theory predicts that phenotypic traits used to choose a mate should reflect honestly the quality of the sender and thus, are often costly. Physiological costs arise if a signal depends on limited nutritional resources. Hence, the nutritional condition of an organism should determine both its quality as a potential mate and its ability to advertise this quality to the choosing sex. In insects, the quality of the offspring's nutrition is often determined by the ovipositing female. A causal connection, however, between the oviposition decisions of the mother and the mating chances of her offspring has never been shown. Here, we demonstrate that females of the parasitic wasp Nasonia vitripennis prefer those hosts for oviposition that have been experimentally enriched in linoleic acid (LA). We show by (13)C-labelling that LA from the host diet is a precursor of the male sex pheromone. Consequently, males from LA-rich hosts produce and release higher amounts of the pheromone and attract more virgin females than males from LA-poor hosts. Finally, males from LA-rich hosts possess three times as many spermatozoa as those from LA-poor hosts. Hence, females making the right oviposition decisions may increase both the fertility and the sexual attractiveness of their sons.

Influence of plant size on female-biased sex allocation in a single-flowered, nectarless herb

PubMed Central

Xiong, Ying-Ze; Xie, Meng; Huang, Shuang-Quan

2016-01-01

Relative allocation to female and male function in hermaphroditic species often departs from strict equisexuality. Increased femaleness with plant size in animal-pollinated species has been proposed in theory and demonstrated in empirical studies. However, such size-dependent sex allocation (SDS) has not been observed in some insect-pollinated species, throwing doubt on the generalization of SDS, that large plants have decelerated male function investment. Himalayan mayapple Podophyllum hexandrum (Berberidaceae) produces a single terminal flower and no nectar, providing a simple system for studying SDS without the confounding effects of flower number and nectar production. To investigate the SDS in P. hexandrum, plant size, biomass of floral organs (stamens, pistils and petals) and gamete production (pollen and ovule number) were measured in four populations in Yunnan Province, northwest China. Isometric allocation to female and male function with plant size was found in two populations, but the prediction of SDS was supported in the other two populations. Using pollen and ovule production as the allocation currency, allocation to female and male function was isometric in all studied populations. Resources allocated to attractive (petals) and sexual (pistils and stamens) structures did not show a significantly disproportionate increase with plant size in three of the four studied populations. The general pattern of isometric allocation to female and male function and to attractive and sexual structures could be attributed to the species being capable of automatic self-pollination, related to low pollen loss, minor deleterious effect of selfing and low importance of attractive structures. However, in further studies, careful consideration should be given to the different currencies used to estimate sex allocation. PMID:26602988

Rapid adaptation to mammalian sociality via sexually selected traits

PubMed Central

2013-01-01

Background Laboratory studies show that the components of sexual selection (e.g., mate choice and intrasexual competition) can profoundly affect the development and fitness of offspring. Less is known, however, about the total effects of sexual selection on offspring in normal social conditions. Complex social networks, such as dominance hierarchies, regulate the opportunity for mating success, and are often missing from laboratory studies. Social selection is an extended view of sexual selection that incorporates competition during sexual and nonsexual interactions, and predicts complex evolutionary dynamics. Whether social selection improves or constrains offspring fitness is controversial. Results To identify fitness consequences of social selection, wild-derived mice that had bred under laboratory conditions for eight generations were re-introduced to naturalistic competition in enclosures for three consecutive generations (promiscuous line). In parallel, a control lineage bred in cages under random mate assignment (monogamous line). A direct competition experiment using second-generation animals revealed that promiscuous line males had greater reproductive success than monogamous line males (particularly during extra-territorial matings), in spite of higher mortality and equivalent success in social dominance and sperm competition. There were no major female fitness effects (though promiscuous line females had fewer litters than monogamous line females). This result suggested that selection primarily acted upon a sexually attractive male phenotype in the promiscuous line, a hypothesis we confirmed in female odor and mating preference trials. Conclusions We present novel evidence for the strength of sexual selection under normal social conditions, and show rapid male adaptation driven largely by sexual trait expression, with tradeoffs in survivorship and female fecundity. Re-introducing wild-derived mice to competition quickly uncovers sexually selected phenotypes otherwise lost in normal colony breeding. PMID:23577674

Gender identity rather than sexual orientation impacts on facial preferences.

PubMed

Ciocca, Giacomo; Limoncin, Erika; Cellerino, Alessandro; Fisher, Alessandra D; Gravina, Giovanni Luca; Carosa, Eleonora; Mollaioli, Daniele; Valenzano, Dario R; Mennucci, Andrea; Bandini, Elisa; Di Stasi, Savino M; Maggi, Mario; Lenzi, Andrea; Jannini, Emmanuele A

2014-10-01

Differences in facial preferences between heterosexual men and women are well documented. It is still a matter of debate, however, how variations in sexual identity/sexual orientation may modify the facial preferences. This study aims to investigate the facial preferences of male-to-female (MtF) individuals with gender dysphoria (GD) and the influence of short-term/long-term relationships on facial preference, in comparison with healthy subjects. Eighteen untreated MtF subjects, 30 heterosexual males, 64 heterosexual females, and 42 homosexual males from university students/staff, at gay events, and in Gender Clinics were shown a composite male or female face. The sexual dimorphism of these pictures was stressed or reduced in a continuous fashion through an open-source morphing program with a sequence of 21 pictures of the same face warped from a feminized to a masculinized shape. An open-source morphing program (gtkmorph) based on the X-Morph algorithm. MtF GD subjects and heterosexual females showed the same pattern of preferences: a clear preference for less dimorphic (more feminized) faces for both short- and long-term relationships. Conversely, both heterosexual and homosexual men selected significantly much more dimorphic faces, showing a preference for hyperfeminized and hypermasculinized faces, respectively. These data show that the facial preferences of MtF GD individuals mirror those of the sex congruent with their gender identity. Conversely, heterosexual males trace the facial preferences of homosexual men, indicating that changes in sexual orientation do not substantially affect preference for the most attractive faces. © 2014 International Society for Sexual Medicine.

Do male secondary sexual characters signal ejaculate quality? A meta-analysis.

PubMed

Mautz, Brian S; Møller, Anders P; Jennions, Michael D

2013-08-01

There are two reasons why researchers are interested in the phenotypic relationship between the expression of male secondary sexual characters (SSCs) and 'ejaculate quality' (defined as sperm/ejaculate traits that are widely assumed to increase female fertility and/or sperm competitiveness). First, if the relationship is positive then females could gain a direct benefit by choosing more attractive males for fertility assurance reasons ('the phenotype-linked fertility' hypothesis). Second, there is much interest in the direction of the correlation between traits favoured by pre-copulatory sexual selection (i.e. affecting mating success) and those favoured by post-copulatory sexual selection (i.e. increasing sperm competitiveness). If the relationship is negative this could lead to the two forms of selection counteracting each other. Theory predicts that the direction of the relationship could be either positive or negative depending on the underlying genetic variance and covariance in each trait, the extent of variation among males in condition (resources available to allocate to reproductive traits), and variation among males in the cost or rate of mating. We conducted a meta-analysis to determine the average relationship between the expression of behavioural and morphological male secondary sexual characters and four assays of ejaculate quality (sperm number, viability, swimming speed and size). Regardless of how the data were partitioned the mean relationship was consistently positive, but always statistically non-significant. The only exception was that secondary sexual character expression was weakly but significantly positively correlated with sperm viability (r = 0.07, P < 0.05). There was no significant difference in the strength or direction of the relationship between behavioural and morphological SSCs, nor among relationships using the four ejaculate quality assays. The implications of our findings are discussed. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

Sexual stigma and symbolic violence experienced, enacted, and counteracted in young Africans' writing about same-sex attraction.

PubMed

Winskell, Kate; Sabben, Gaëlle

2016-07-01

There is growing recognition of the health disparities faced by sexual minority populations and the critical role played by sexual stigma in increasing their vulnerability. Experienced, anticipated, and internalized, stigma based on sexual orientation reduces access to HIV/STI prevention and treatment services among African men who have sex with men and has been linked to compromised mental health, risk-taking, and HIV status. It is likely that similar processes undermine the health of sexual minority African women and transgender and non-binary people. There is a need for increased understanding of both the contextual factors and the cultural meanings, or symbolic violence, that inform sexual stigma and harmful stigma management strategies in contexts that are culturally and socio-politically oppressive for sexual and gender minorities. Using thematic data analysis and narrative-based methodologies, we analyzed narratives and essays on same-sex attraction contributed by young people aged 13-24 from ten African countries to a Spring 2013 scriptwriting competition on HIV, sexuality, and related themes. Submitted by 27 male and 29 female authors, the texts were written in response to a prompt inviting participants to "Tell a story about someone who is attracted to people of the same sex". We analyzed the ways in which sexual stigma and its effects are described, enacted, and counteracted in the texts. The data provide insights into the social and symbolic processes that create and sustain sexual stigma in the context of broader transnational discourses. The data shed light on psychosocial challenges faced by sexual minority youth and identify both rhetoric, stereotypes, and discourse that devalue them and representations that counteract this symbolic violence. We share our findings in the hope they may inform education and communication programming as part of multi-level efforts to improve the health and human rights of sexual minority populations in sub-Saharan Africa. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structure-Activity Studies of Semiochemicals from the Spider Orchid Caladenia plicata for Sexual Deception.

PubMed

Bohman, Bjorn; Karton, Amir; Flematti, Gavin R; Scaffidi, Adrian; Peakall, Rod

2018-05-01

Sexually deceptive orchids attract specific pollinators by mimicking insect sex pheromones. Normally this mimicry is very specific and identical compounds have been identified from orchids and matching females of the pollinators. In this study, we conduct a detailed structure-activity investigation on isomers of the semiochemicals involved in the sexual attraction of the male pollinator of the spider orchid Caladenia plicata. This orchid employs an unusual blend of two biosynthetically unrelated compounds, (S)-β-citronellol and 2-hydroxy-6-methylacetophenone, to lure its Zeleboria sp. thynnine wasp pollinator. We show that the blend is barely attractive when (S)-β-citronellol is substituted with its enantiomer, (R)-β-citronellol. Furthermore, none of the nine-possible alternative hydroxy-methylacetophenone regioisomers of the natural semiochemical are active when substituted for the natural 2-hydroxy-6-methylacetophenone. Our results were surprising given the structural similarity between the active compound and some of the analogues tested, and results from previous studies in other sexually deceptive orchid/wasp systems where substitution with analogues was possible. Interestingly, high-level ab initio and density functional theory calculations of the hydroxy-methylacetophenones revealed that the active natural isomer, 2-hydroxy-6-methylacetophenone, has the strongest intramolecular hydrogen bond of all regioisomers, which at least in part may explain the specific activity.

Dimensionality and Transcultural Specificity of the Sexual Attraction Questionnaire (SAQ).

PubMed

Fernández, Juan; Quiroga, María Angeles; Icaza, Vanessa J; Escorial, Sergio

2012-03-01

Sexual attraction was considered a component of sexual orientation from the beginning of the second half of the 20th century to present times. However, some recent researchers have studied sexual attraction as an independent field measuring it by the Sexual Attraction Questionnaire (SAQ). This study analyzes sexual attraction through the SAQ in 400 university students from a Peruvian catholic university. These participants -191 women and 209 men- show a very diverse curricular background. The following hypotheses were tested: a) the structure of the SAQ, pointing out two concepts: attraction to men and attraction to women; b) the high inverse correlation between these two concepts or factors; c) the specific impact of this context in sexual attraction: higher percentage of attracted by none of the sexes and lower percentage of attracted to the opposite sex, in comparison with other contexts; and d) the Lippa prediction (2006, 2007), regarding a higher polarization of sexual attraction for men than for women. Results support the first three hypotheses. Clarifications are laid down with regard to the fourth one. Discussion focuses on theoretical and applied advantages of using the SAQ as opposed to the frequent use of a single item of sexual attraction for each sex.

Male hamster investigatory and copulatory responses to vaginal discharge: an attempt to impart sexual significance to an arbitrary chemosensory stimulus.

PubMed

Macrides, F; Clancy, A N; Singer, A G; Agosta, W C

1984-10-01

Hamster vaginal discharge elicits intense genital investigation and facilitates overt copulatory behavior toward anesthetized males (female surrogates) whose hindquarters have been scented with this material. The ability of an arbitrary chemosensory stimulus to acquire behavioral activity like that of vaginal discharge through association with maternal stimuli and/or adult sexual experience was examined in male hamsters. Vanillin was used as the arbitrary stimulus because it is attractive to hamsters, is not likely to be a natural constituent of hamster scents, is not known to exert any adverse physiological effects, and is a subliming solid with an extremely long persistence when used as an artificial scent. The males were reared by vanillin-scented or control solvent (water)-scented foster mothers, and in adulthood were paired repeatedly with vanillin- or solvent-scented receptive females. Behavioral testing with scented surrogates was performed one week preceding, and again following, the sexual pairings. Rearing by vanillin-scented mothers modestly but significantly increased the amount of time sexually naive males spent investigating the hindquarters as compared to other body regions of vanillin-scented surrogates. However, neither neonatal nor adult interactions with vanillin-scented females imparted to this stimulus the capacity to facilitate overt copulatory behavior. Also, regardless of the males' exposure history, only vaginal discharge caused the males to direct their investigatory behavior predominantly toward the hindquarters. The characteristic investigatory and copulatory responses exhibited by male hamsters toward vaginal discharge thus do not appear to be readily developed toward arbitrary chemosensory stimuli associated with particular females to which the males have been exposed.

Adiposity, compared with masculinity, serves as a more valid cue to immunocompetence in human mate choice.

PubMed

Rantala, Markus J; Coetzee, Vinet; Moore, Fhionna R; Skrinda, Ilona; Kecko, Sanita; Krama, Tatjana; Kivleniece, Inese; Krams, Indrikis

2013-01-22

According to the 'good genes' hypothesis, females choose males based on traits that indicate the male's genetic quality in terms of disease resistance. The 'immunocompetence handicap hypothesis' proposed that secondary sexual traits serve as indicators of male genetic quality, because they indicate that males can contend with the immunosuppressive effects of testosterone. Masculinity is commonly assumed to serve as such a secondary sexual trait. Yet, women do not consistently prefer masculine looking men, nor is masculinity consistently related to health across studies. Here, we show that adiposity, but not masculinity, significantly mediates the relationship between a direct measure of immune response (hepatitis B antibody response) and attractiveness for both body and facial measurements. In addition, we show that circulating testosterone is more closely associated with adiposity than masculinity. These findings indicate that adiposity, compared with masculinity, serves as a more important cue to immunocompetence in female mate choice.

Recalled Separation Anxiety in Childhood in Istmo Zapotec Men, Women, and Muxes.

PubMed

Gómez, Francisco R; Semenyna, Scott W; Court, Lucas; Vasey, Paul L

2017-01-01

The Istmo Zapotec are a pre-Columbian cultural group indigenous to the Istmo region of Oaxaca, Mexico. Istmo Zapotec recognize three genders: men, women, and muxes. Like Istmo Zapotec men, muxes are biological males. However, unlike Istmo Zapotec men, most muxes are exclusively androphilic (i.e., sexually attracted to adult males), relatively feminine, and routinely adopt the receptive role during anal intercourse. Furthermore, the Istmo Zapotec recognize two types of muxes: muxe gunaa, who resemble the transgender androphilic males that are common in many non-Western cultures, and muxe nguiiu, who resemble the cisgender androphilic males ("gay" men) common in Western cultures. Retrospective research conducted in Canada and Samoa demonstrates that cisgender and transgender androphilic males recall elevated indicators of childhood separation anxiety (i.e., feelings of distress related to separation from major attachment figures) when compared to males who are gynephilic (i.e., sexually attracted to adult females). The present study compared recalled indicators of childhood separation anxiety among Istmo Zapotec men, women, muxe gunaa, and muxe nguiiu (N = 454). Men recalled significantly lower levels of childhood separation anxiety compared to all other groups (all p < .042). No additional group differences were found. Our results are consistent with previous research conducted in Canada and Samoa, suggesting that elevated childhood separation anxiety is a developmental correlate of male androphilia that is cross-culturally universal. This research is also consistent with the conclusion that cisgender and transgender male androphiles share a common biological and developmental foundation despite being different in appearance.

Multivariate sexual selection on male tegmina in wild populations of sagebrush crickets, Cyphoderris strepitans (Orthoptera: Haglidae).

PubMed

Ower, G D; Hunt, J; Sakaluk, S K

2017-02-01

Although the strength and form of sexual selection on song in male crickets have been studied extensively, few studies have examined selection on the morphological structures that underlie variation in males' song, particularly in wild populations. Geometric morphometric techniques were used to measure sexual selection on the shape, size and symmetry of both top and bottom tegmina in wild populations of sagebrush crickets, a species in which nuptial feeding by females imposes an unambiguous phenotypic marker on males. The size of the tegmina negatively covaried with song dominant frequency and positively covaried with song pulse duration. Sexual selection was more intense on the bottom tegmen, conceivably because it interacts more freely with the subtegminal airspace, which may play a role in song amplification. An expanded coastal/subcostal region was one of the phenotypes strongly favoured by disruptive selection on the bottom tegmen, an adaptation that may form a more effective seal with the thorax to prevent noise cancellation. Directional selection also favoured increased symmetry in tegminal shape. Assuming more symmetrical males are better able to buffer against developmental noise, the song produced by these males may make them more attractive to females. Despite the strong stabilizing selection documented previously on the dominant frequency of the song, stabilizing selection on the resonator that regulates dominant frequency was surprisingly absent. Nonetheless, wing morphology had an important influence on song structure and appears to be subject to significant linear and nonlinear sexual selection through female mate choice. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Fear, food and sexual ornamentation: plasticity of colour development in Trinidadian guppies

PubMed Central

Ruell, E. W.; Handelsman, C. A.; Hawkins, C. L.; Sofaer, H. R.; Ghalambor, C. K.; Angeloni, L.

2013-01-01

The evolution of male ornamentation often reflects compromises between sexual and natural selection, but it may also be influenced by phenotypic plasticity. We investigated the developmental plasticity of male colour ornamentation in Trinidadian guppies in response to two environmental variables that covary in nature: predation risk and food availability. We found that exposure to chemical predator cues delayed the development of pigment-based colour elements, which are conspicuous to visual-oriented predators. Predator cues also reduced the size of colour elements at the time of maturity and caused adult males to be less colourful. To the best of our knowledge, these findings provide the first example of a plastic reduction in the development of a sexually selected male ornament in response to predator cues. The influence of predator cues on ornamentation probably affects individual fitness by reducing conspicuousness to predators, but could reduce attractiveness to females. Reduced food availability during development caused males to delay the development of colour elements and mature later, probably reflecting a physiological constraint, but their coloration at maturity and later in adulthood was largely unaffected, suggesting that variation in food quantity without variation in quality does not contribute to condition dependence of the trait. PMID:23466982

Histological Development of Male Reproductive Organs in Microminipigs.

PubMed

Kangawa, Akihisa; Otake, Masayoshi; Enya, Satoko; Yoshida, Toshinori; Shibata, Masatoshi

2016-12-01

Microminipigs are becoming increasingly attractive alternatives for various experimental applications, such as general toxicology studies, owing to their manageable size. However, there are limited studies on the male reproductive organs of microminipigs, particularly on the histological aspects of sexual maturity. To clarify the development of male reproductive organs, 35 male microminipigs, aged 0 to 12 months, were used in this study. Histological and histomorphological evaluation was performed based on spermatogenic development, measurement of tubular structure in testes and epididymides, and histological progress of accessory glands. In addition, spontaneous testicular changes were quantitatively assessed. Histologically, male microminipigs sexually matured around 4.5 months of age, when spermatogenesis in testes and structural development in genital organs were completed. Spontaneous testicular changes occurred in all the animals investigated. Multinucleated giant cell was most commonly observed, followed by hypospermatogenesis and tubular atrophy/hypoplasia. However, the number of affected tubules was less than 1% in testes after 4.5 months of age, suggesting that the influence of these changes on evaluation of toxicity studies may be minimal. It is preferable to use sexually mature animals in toxicology studies; therefore, the information obtained by the present study will be helpful for future toxicity evaluations in microminipigs.

Flying in tune: sexual recognition in mosquitoes.

PubMed

Gibson, Gabriella; Russell, Ian

2006-07-11

Mosquitoes hear with their antennae, which in most species are sexually dimorphic. Johnston, who discovered the mosquito auditory organ at the base of the antenna 150 years ago, speculated that audition was involved with mating behaviour. Indeed, male mosquitoes are attracted to female flight tones. The male auditory organ has been proposed to act as an acoustic filter for female flight tones, but female auditory behavior is unknown. We show, for the first time, interactive auditory behavior between males and females that leads to sexual recognition. Individual males and females both respond to pure tones by altering wing-beat frequency. Behavioral auditory tuning curves, based on minimum threshold sound levels that elicit a change in wing-beat frequency to pure tones, are sharper than the mechanical tuning of the antennae, with males being more sensitive than females. We flew opposite-sex pairs of tethered Toxorhynchites brevipalpis and found that each mosquito alters its wing-beat frequency in response to the flight tone of the other, so that within seconds their flight-tone frequencies are closely matched, if not completely synchronized. The flight tones of same-sex pairs may converge in frequency but eventually diverge dramatically.

Lip colour affects perceived sex typicality and attractiveness of human faces.

PubMed

Stephen, Ian D; McKeegan, Angela M

2010-01-01

The luminance contrast between facial features and facial skin is greater in women than in men, and women's use of make-up enhances this contrast. In black-and-white photographs, increased luminance contrast enhances femininity and attractiveness in women's faces, but reduces masculinity and attractiveness in men's faces. In Caucasians, much of the contrast between the lips and facial skin is in redness. Red lips have been considered attractive in women in geographically and temporally diverse cultures, possibly because they mimic vasodilation associated with sexual arousal. Here, we investigate the effects of lip luminance and colour contrast on the attractiveness and sex typicality (masculinity/femininity) of human faces. In a Caucasian sample, we allowed participants to manipulate the colour of the lips in colour-calibrated face photographs along CIELab L* (light--dark), a* (red--green), and b* (yellow--blue) axes to enhance apparent attractiveness and sex typicality. Participants increased redness contrast to enhance femininity and attractiveness of female faces, but reduced redness contrast to enhance masculinity of men's faces. Lip blueness was reduced more in female than male faces. Increased lightness contrast enhanced the attractiveness of both sexes, and had little effect on perceptions of sex typicality. The association between lip colour contrast and attractiveness in women's faces may be attributable to its association with oxygenated blood perfusion indicating oestrogen levels, sexual arousal, and cardiac and respiratory health.

Electrophysiological evidence of perceived sexual attractiveness for human female bodies varying in waist-to-hip ratio.

PubMed

Del Zotto, Marzia; Pegna, Alan J

2017-06-01

The dynamics of brain activation reflecting attractiveness in humans are unclear. Among the different features affecting attractiveness of the female body, the waist-to-hip ratio (WHR) is considered to be crucial. To date, however, no event-related potential (ERP) study has addressed the question of its associated pattern of brain activation. We carried out two different experiments: (a) a behavioural study, to judge the level of attractiveness of female realistic models depicting 4 different WHRs (0.6, 0.7, 0.8, 0.9) with and without clothes; (b) an EEG paradigm, to record brain activity while participants (heterosexual men and women) viewed these same models. Behavioural results showed that WHRs of 0.7 were considered more attractive than the others. ERP analyses revealed a different pattern of activation for male and female viewers. The 0.7 ratio elicited greater positivity at the P1 level in male viewers but not females. Naked bodies increased the N190 in both groups and peaked earlier for the 0.7 ratio in the male viewers. Finally, the late positive component (LPC) was found to be greater in male than in female viewers and was globally more marked for naked bodies as well as WHRs of 0.7 in both groups of viewers. These results provide the first electrophysiological evidence of specific time periods linked to the processing of a body feature denoting attractiveness and therefore playing a role in mate choice.

Sex-dimorphic face shape preference in heterosexual and homosexual men and women.

PubMed

Glassenberg, Aaron N; Feinberg, David R; Jones, Benedict C; Little, Anthony C; Debruine, Lisa M

2010-12-01

Studies have used manipulated faces to test the preferences of heterosexual individuals for sexually dimorphic facial cues. In contrast to previous studies, which have generally excluded homosexual participants, we directly compared homosexual and heterosexual male and female preferences for manipulated sexual dimorphism in faces (homosexual males: n = 311; heterosexual males: n = 215; homosexual females: n = 159; heterosexual females: n = 218). Prior studies on sexual orientation and preferences for faces that were paired with masculine and feminine behavioral descriptors suggest that homosexual men prefer more masculine men and that homosexual women demonstrate no preference for either masculinity or femininity in women. In our study, we tested for similarities and differences among heterosexual and homosexual males and females with regard to their preferences for a more specific aspect of faces: sexual dimorphism of face shape. Homosexual men demonstrated stronger preferences for masculinity in male faces than did all of the other groups. Homosexual women demonstrated stronger preferences for masculinity in female faces than did heterosexual women. These results suggest attractiveness judgments of same-sex faces made by homosexual individuals are not a mirror image of those made by heterosexual individuals of the opposite sex. Our data suggest that face preferences of homosexual individuals reflect a system of biologically and socially guided preferences at least as complex as those found among heterosexual individuals.

Reported sexual desire predicts men's preferences for sexually dimorphic cues in women's faces.

PubMed

Jones, Benedict C; Little, Anthony C; Watkins, Christopher D; Welling, Lisa L M; DeBruine, Lisa M

2011-12-01

Recent studies investigating the relationship between sexual desire and sexual attraction have found that heterosexual women's reported sexual desire is positively correlated with their reported attraction to both own- and opposite-sex individuals, but that heterosexual men's reported sexual desire is positively correlated with their reported attraction to opposite-sex individuals only. These findings have led to the proposal that sexual desire is a generalized energizer of sexual attraction in heterosexual women (i.e., influences women's attraction to both men and women), but only energizes heterosexual men's sexual attraction to women. Here we show that heterosexual men's scores on the Sexual Desire Inventory-2 were positively correlated with their preferences for exaggerated sex-typical shape cues in opposite-sex, but not own-sex, faces. Together with previous research showing that heterosexual women's reported sexual desire is positively correlated with their preferences for exaggerated sex-typical shape cues in both own- and opposite-sex faces, our findings present novel converging evidence for sex-specific relationships between sexual desire and attractiveness judgments of own- and opposite-sex individuals.

Handgrip Strength as a Darwinian Fitness Indicator in Men.

PubMed

Gallup, Andrew C; Fink, Bernhard

2018-01-01

Handgrip strength (HGS) is a robust measure of overall muscular strength and function, and has long been predictive of a multitude of health factors and physical outcomes for both men and women. The fact that HGS represents such a ubiquitous measure of health and vitality may reflect the significance of this trait during human evolution. This trait is also highly sexually dimorphic due to influences of androgenic hormones and fat-free body mass, suggesting that it has been further elaborated through sexual selection. Consistent with this view, research within evolutionary psychology and related fields has documented distinct relationships between HGS and measures of social and sexual behavior, especially in men. Here, we review studies across different societies and cultural contexts showing that male HGS predicts measures of aggression and social dominance, perceived formidability, male-typical body morphology and movement, courtship display, physical attractiveness, and sexual behavior and reproductive fitness. These findings underscore the value of including HGS as an independent measure within studies examining human sexual selection, and corroborate existing research suggesting that specific features of physical strength have and continue to be under positive directional selection in men.

Selection for predation, not female fecundity, explains sexual size dimorphism in the orchid mantises.

PubMed

Svenson, Gavin J; Brannoch, Sydney K; Rodrigues, Henrique M; O'Hanlon, James C; Wieland, Frank

2016-12-01

Here we reconstruct the evolutionary shift towards floral simulation in orchid mantises and suggest female predatory selection as the likely driving force behind the development of extreme sexual size dimorphism. Through analysis of body size data and phylogenetic modelling of trait evolution, we recovered an ancestral shift towards sexual dimorphisms in both size and appearance in a lineage of flower-associated praying mantises. Sedentary female flower mantises dramatically increased in size prior to a transition from camouflaged, ambush predation to a floral simulation strategy, gaining access to, and visually attracting, a novel resource: large pollinating insects. Male flower mantises, however, remained small and mobile to facilitate mate-finding and reproductive success, consistent with ancestral male life strategy. Although moderate sexual size dimorphisms are common in many arthropod lineages, the predominant explanation is female size increase for increased fecundity. However, sex-dependent selective pressures acting outside of female fecundity have been suggested as mechanisms behind niche dimorphisms. Our hypothesised role of predatory selection acting on females to generate both extreme sexual size dimorphism coupled with niche dimorphism is novel among arthropods.

Selection for predation, not female fecundity, explains sexual size dimorphism in the orchid mantises

PubMed Central

Svenson, Gavin J.; Brannoch, Sydney K.; Rodrigues, Henrique M.; O’Hanlon, James C.; Wieland, Frank

2016-01-01

Here we reconstruct the evolutionary shift towards floral simulation in orchid mantises and suggest female predatory selection as the likely driving force behind the development of extreme sexual size dimorphism. Through analysis of body size data and phylogenetic modelling of trait evolution, we recovered an ancestral shift towards sexual dimorphisms in both size and appearance in a lineage of flower-associated praying mantises. Sedentary female flower mantises dramatically increased in size prior to a transition from camouflaged, ambush predation to a floral simulation strategy, gaining access to, and visually attracting, a novel resource: large pollinating insects. Male flower mantises, however, remained small and mobile to facilitate mate-finding and reproductive success, consistent with ancestral male life strategy. Although moderate sexual size dimorphisms are common in many arthropod lineages, the predominant explanation is female size increase for increased fecundity. However, sex-dependent selective pressures acting outside of female fecundity have been suggested as mechanisms behind niche dimorphisms. Our hypothesised role of predatory selection acting on females to generate both extreme sexual size dimorphism coupled with niche dimorphism is novel among arthropods. PMID:27905469

Androgenic regulation of chemoinvestigatory behaviors in male and female hamsters.

PubMed

Powers, J B; Bergondy, M L

1983-03-01

In male hamsters, chemosensory responsiveness to sexually relevant female odors is facilitated by testosterone (T). Some evidence suggests that this is not a sexually dimorphic response in that adult females can respond similarly to males following administration of T. This was evaluated and additionally, the hypothesis that facilitation of chemosensory responsiveness by T might be mediated by the conversion of T to aromatized or 5 alpha-reduced metabolites was tested. In 2-min tests, we measured the time adult males or females investigated female hamster vaginal secretion (FHVS). These animals were gonadectomized and administered T, 5 alpha-dihydrotestosterone (DHT), estradiol (E2), or a combination of DHT and E2, by subcutaneous implantation of Silastic capsules. FHVS tests were conducted either 2 and 4 weeks, or 4 and 6 weeks subsequent to gonadectomy and hormone treatment. Comparisons among groups receiving different hormone doses indicated that (1) males and females are not equally responsive to the attractant properties of FHVS, and that (2) neither DHT, E2, nor their combination, can duplicate the effects of T in facilitating responsiveness to FHVS in either sex. The copulatory behavior of males under the hormone conditions described was also tested and it was found that variations in the rate at which the test males sniffed or licked the receptive female's anogenital region correlated with variations in measures of the males' sexual performance.

The influence of antibiotic treatment of bitches in oestrus on their attractiveness to males during mating.

PubMed

Dziecioł, M; Nizański, W; Stańczyk, E; Kozdrowski, R; Najder-Kozdrowska, L; Twardoń, J

2013-01-01

The aim of this study was to evaluate the influence of the antibiotic treatment, including the mode of drugs administration, on bitches' attractiveness to the stud dogs during mating. Moreover, we tried to estimate the possibility of aversive effect of the drug vehicle on the male behavior. In experiment I, four bitches in oestrus without antibiotic treatment (group A), four bitches treated with intravaginal antibiotic (group B) and four bitches treated with intramuscular antibiotic (group C) were presented to four stud dogs. In experiment II, bitches in oestrus (n = 5) were presented to the males (n = 2) before and after the application to the females' vulva the antibiotic carrier--Miglyol 840 (Sasol, Germany). In both experiments the presence of the typical sexual behavior of the males (sniffing, licking the vulva and anal region, mating attempts) was evaluated. In experiment III the reaction of the males to the samples containing oestrual discharge from the bitches untreated and treated with antibiotics was evaluated. In the last part of study the aversion reaction to the samples containing antibiotic and the antibiotic carrier was evaluated. The results of experiments showed that females treated with the antibiotics were less attractive to males than untreated females, regardless of the method of administration. We did not observe adverse effect of the antibiotic carrier but samples from the bitches treated with antibiotics were significantly less attractive to the males. We concluded that the reason for reduced attractiveness of the bitches in oestrus after antibiotic treatment was the changes in semiochemical signal emitted by treated females as a consequence of elimination of the vaginal bacterial flora, which seems to be involved in creation of the typical, recognizable by the stud dogs, oestrual signal but also by the possible covering effect of used drugs.

Positive Perceptions of Genital Appearance and Feeling Sexually Attractive: Is It a Matter of Sexual Esteem?

PubMed

Amos, Natalie; McCabe, Marita

2016-07-01

The present study examined the relationship between perceptions of genital appearance and self-perceived sexual attractiveness. The study sample included men and women (aged 18-45 years, M = 23.7, SD = 4.98) who identified as heterosexual (n = 1017), gay or lesbian (n = 1225), or bisexual (n = 651). Participants responded to an online survey assessing their self-perceived sexual attractiveness, genital self-image, genital self-consciousness during sexual activity, and sexual esteem. Based on previous findings, we hypothesized a positive link between genital self-perceptions and self-perceived sexual attractiveness, with sexual esteem acting as a mediator. We tested this hypothesis using structural equation modeling. Analyses revealed a significant association between both genital self-image and genital self-consciousness and self-perceived sexual attractiveness. However, these relationships were at least partially mediated by sexual esteem, across both gender and sexual orientation. The findings suggest that, regardless of gender or sexual orientation, individuals who maintain a positive genital self-image or lack genital self-consciousness, are more likely to experience greater sexual esteem, and in turn, feel more sexually attractive. The findings have implications for the importance of genital appearance perceptions and improving individuals' sexual esteem and self-perceived sexual attractiveness.

Use of female nest characteristics in the sexual behaviour of male sockeye salmon

USGS Publications Warehouse

Hamon, T.R.; Foote, C.J.; Brown, G.S.

1999-01-01

On three island beaches in Iliamna Lake, Alaska, large numbers of male sockeye salmon gathered and spawned in artificial excavations that mimicked a female's nest immediately prior to spawning, while apparently ignoring the control site. The number of males attracted was correlated positively with changes in the operational sex ratio. In contrast, on the mainland beach examined, no reaction to the artificial nests was apparent. The results are discussed in terms of mate searching behaviour by males, the duration of the spawning period, and associated selection pressures on males to use characteristics of their environment that provide information on availability of females.

Investigations of novel unsaturated bile salts of male sea lamprey as potential chemical cues

USGS Publications Warehouse

Johnson, Nicholas S.; Yun, Sang-Seon; Li, Weiming

2014-01-01

Sulfated bile salts function as chemical cues that coordinate reproduction in sea lamprey, Petromyzon marinus. 7α, 12α, 24-trihydroxy-5α-cholan-3-one 24-sulfate (3kPZS) is the most abundant known bile salt released by sexually mature male sea lampreys and attracts ovulated females. However, previous studies showed that the male-produced pheromone consists of unidentified components in addition to 3kPZS. Here, analysis of water conditioned with mature male sea lampreys indicated the presence of 4 oxidized, unsaturated compounds with molecular weights of 466 Da, 468 Da, and 2 of 470 Da. These compounds were not detectable in water conditioned with immature male sea lampreys. By using mass spectrometry, 4 A-ring unsaturated sulfated bile salts were tentatively identified from male washings as 2 4-ene, a 1-ene, and a 1,4-diene analogs. These were synthesized to determine if they attracted ovulated female sea lampreys to spawning nests in natural streams. One of the novel synthetic bile salts, 3 keto-1-ene PZS, attracted ovulated females to the point of application at a concentration of 10-12 M. This study reveals the structural diversity of bile salts in sea lamprey, some of which have been demonstrated to be pheromonal cues.

Patterns of Asexuality in China: Sexual Activity, Sexual and Romantic Attraction, and Sexual Desire.

PubMed

Zheng, Lijun; Su, Yanchen

2018-05-01

This study examined patterns of asexuality in Chinese asexual people in terms of sexual activities, sexual/romantic attraction, and sexual desire. The sample included 227 (64 men and 163 women) asexual participants and 57 (26 men and 31 women) uncertain asexual participants recruited from social networks for asexual people. The control group included 217 (115 men and 102 women) heterosexual participants recruited from general social networks. Participants scoring 40 or higher on the Asexuality Identification Scale were classified as asexual. Asexual participants reported having less frequent masturbation, sexual intercourse experience, and sexual and romantic attraction compared to heterosexual participants. Lower sexual attraction among asexuals indicated that "people who experience little or no sexual attraction" would be a more appropriate definition of asexuality. The pattern of uncertain asexual participants' sexual/romantic attraction and sexual desire was intermediate between heterosexual and asexual participants. Asexual participants scored significantly lower on dyadic sexual desire and slightly lower on solitary sexual desire than heterosexual participants. There were significant differences in sexual activities and solitary sexual desire among romantic orientation categories. Homoromantic participants showed higher dyadic sexual desire and were more likely to engage in masturbation, indicating the heterogeneity among asexual people. The findings indicated that Chinese asexual people showed similar patterns of asexuality as in Western nations. Specifically, asexual people have little or no sexual attraction, non-partner-orientated sexual desire, and are heterogeneous in sexual activities and sexual desire. This implies similar mechanisms underlying the etiology of asexuality across cultures.

The wandering mind of men: ERP evidence for gender differences in attention bias towards attractive opposite sex faces

PubMed Central

Crawford, Helen; van Vugt, Mark

2011-01-01

To examine the time course and automaticity of our attention bias towards attractive opposite sex faces, event-related potentials (ERPs) were recorded from 20 males and 20 females while they carried out a covert orienting task. Faces that were high, low or average in attractiveness, were presented in focus of attention, but were unrelated to task goals. Across the entire sample larger P2 amplitudes were found in response to both attractive and unattractive opposite sex faces, presumably reflecting early implicit selective attention to distinctive faces. In male but not female participants this was followed by an increased late slow wave for the attractive faces, signifying heightened processing linked to motivated attention. This latter finding is consistent with sexual strategy theory, which suggests that men and women have evolved to pursue different mating strategies with men being more attentive to cues such as facial beauty. In general, our ERP results suggest that, in addition to threat-related stimuli, other evolutionary-relevant information is also prioritized by our attention systems. PMID:20601424

The wandering mind of men: ERP evidence for gender differences in attention bias towards attractive opposite sex faces.

PubMed

van Hooff, Johanna C; Crawford, Helen; van Vugt, Mark

2011-09-01

To examine the time course and automaticity of our attention bias towards attractive opposite sex faces, event-related potentials (ERPs) were recorded from 20 males and 20 females while they carried out a covert orienting task. Faces that were high, low or average in attractiveness, were presented in focus of attention, but were unrelated to task goals. Across the entire sample larger P2 amplitudes were found in response to both attractive and unattractive opposite sex faces, presumably reflecting early implicit selective attention to distinctive faces. In male but not female participants this was followed by an increased late slow wave for the attractive faces, signifying heightened processing linked to motivated attention. This latter finding is consistent with sexual strategy theory, which suggests that men and women have evolved to pursue different mating strategies with men being more attentive to cues such as facial beauty. In general, our ERP results suggest that, in addition to threat-related stimuli, other evolutionary-relevant information is also prioritized by our attention systems.

Electrophysiological response and attraction of emerald ash borer to green leaf volatiles (GLVs) emitted by host foliage.

PubMed

de Groot, Peter; Grant, Gary G; Poland, Therese M; Scharbach, Roger; Buchan, Linda; Nott, Reginald W; Macdonald, Linda; Pitt, Doug

2008-09-01

Green leaf volatiles (GLVs) function as host attractants, pheromone synergists, or sexual kairomones for a number of coleopteran folivores. Hence, we focused on host GLVs to determine if they were attractive to adults of the emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae), which feeds on ash (Fraxinus) foliage. Eight GLVs were identified by chromatography-electroantennogram (GC) and GC-mass spectrometry in foliar headspace volatiles collected in traps containing Super-Q from white ash, Fraxinus americana, and green ash, Fraxinus pennsylvanica, trees. GLVs in the aeration extracts elicited antennal responses from both male and female adults in gas chromatography-electroantennogram detection bioassays. Male antennae were more responsive than female antennae and showed the strongest response to (Z)-3-hexenol. Six field experiments were conducted in Canada and the USA from 2004 to 2006 to evaluate the attractiveness of candidate GLVs, in various lure combinations and dosages. Field experiments demonstrated that lures containing (Z)-3-hexenol were the most effective in increasing trap catch when placed on purple traps in open areas or along the edges of woodlots containing ash. Lures with (Z)-3-hexenol were more attractive to males than females, and dosage may be a factor determining its effectiveness.

Evidence for partial overlap of male olfactory cues in lampreys

USGS Publications Warehouse

Buchinger, Tyler J.; Li, Ke; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas S.

2016-01-01

Animals rely on a mosaic of complex information to find and evaluate mates. Pheromones, often comprised of multiple components, are considered to be particularly important for species-recognition in many species. While the evolution of species-specific pheromone blends is well-described in many insects, very few vertebrate pheromones have been studied in a macro-evolutionary context. Here, we report a phylogenetic comparison of multi-component male odours that guide reproduction in lampreys. Chemical profiling of sexually mature males from eleven species of lamprey, representing six of ten genera and two of three families, indicated the chemical profiles of sexually mature male odours are partially shared among species. Behavioural assays conducted with four species sympatric in the Laurentian Great Lakes indicated asymmetric female responses to heterospecific odours, where Petromyzon marinus were attracted to male odour collected from all species tested but other species generally preferred only the odour of conspecifics. Electro-olfactogram recordings from P. marinusindicated that although P. marinus exhibited behavioural responses to odours from males of all species, at least some of the compounds that elicited olfactory responses were different in conspecific male odours compared to heterospecific male odours. We conclude that some of the compounds released by sexually mature males are shared among species and elicit olfactory and behavioural responses in P. marinus, and suggest that our results provide evidence for partial overlap of male olfactory cues among lampreys. Further characterization of the chemical identities of odour components is needed to confirm shared pheromones among species.

Multiple roles of a male-specific compound in the sexual behavior of the dried bean beetle, Acanthoscelides obtectus.

PubMed

Vuts, József; Powers, Stephen J; Caulfield, John C; Pickett, John A; Birkett, Michael A

2015-03-01

Males of Acanthoscelides obtectus (Coleoptera: Chrysomelidae, Bruchinae) emit methyl (E,R)-2,4,5-tetradecatrienoate that attracts females for mating. This study identified further roles for this compound in the sexual behavior of A. obtectus. Earlier observations revealed that males touched females with their antennae while tandem-running with them and initiated mounting and copulation, whereas they showed no such behavior toward other males. A series of subsequent laboratory choice tests were set up to establish if certain cuticular compounds aid contact sex recognition in A. obtectus. Males chose virgin females over other males. The activity toward females could be eliminated by rinsing with hexane, but was regained by application of female extract onto previously rinsed females. Gas chromatographic (GC) comparison of hexane extracts revealed the presence of two male-specific compounds, methyl (E,R)-2,4,5-tetradecatrienoate and octadecanal, which were absent from the behaviorally active female samples. Of the two compounds, methyl (E,R)-2,4,5-tetradecatrienoate was found to be responsible for the inhibition of male sexual behavior, similar to that observed with crude male extracts applied to virgin females. Furthermore, males preferred virgin over mated females. GC analyses revealed the presence of methyl (E,R)-2,4,5-tetradecatrienoate in mated females in amounts sufficient to curtail mating attempts. It appears that methyl (E,R)-2,4,5-tetradecatrienoate, besides being a male-produced sex pheromone, acts as a male-recognition signal in A. obtectus. Males also transfer it onto females during mating, resulting in mated females being avoided by courting males.

Sexual selection and the evolution of male pheromone glands in philanthine wasps (Hymenoptera, Crabronidae).

PubMed

Weiss, Katharina; Herzner, Gudrun; Strohm, Erhard

2017-06-06

Sexual selection is thought to promote evolutionary changes and diversification. However, the impact of sexual selection in relation to other selective forces is difficult to evaluate. Male digger wasps of the tribe Philanthini (Hymenoptera, Philanthinae) scent mark territories to attract receptive females. Consequently, the organs for production and storage of the marking secretion, the mandibular gland (MG) and the postpharyngeal gland (PPG), are subject to sexual selection. In female Philanthini, these glands are most likely solely subject to natural selection and show very little morphological diversity. According to the hypothesis that sexual selection drives interspecific diversity, we predicted that the MG and PPG show higher interspecific variation in males than in females. Using histological methods, 3D-reconstructions, and multivariate statistical analysis of morphological characters, we conducted a comparative analysis of the MG and the PPG in males of 30 species of Philanthini and three species of the Cercerini and Aphilanthopsini, two related tribes within the Philanthinae. We found substantial interspecific diversity in gland morphology with regard to gland incidence, size, shape and the type of associated secretory cells. Overall there was a phylogenetic trend: Ensuing from the large MGs and small PPGs of male Cercerini and Aphilanthopsini, the size and complexity of the MG was reduced in male Philanthini, while their PPG became considerably enlarged, substantially more complex, and associated with an apparently novel type of secretory cells. In some clades of the Philanthini the MG was even lost and entirely replaced by the PPG. However, several species showed reversals of and exceptions from this trend. Head gland morphology was significantly more diverse among male than among female Philanthinae. Our results show considerable variation in male head glands including the loss of an entire gland system and the evolution of a novel kind of secretory cells, confirming the prediction that interspecific diversity in head gland morphology is higher in male than in female Philanthini. We discuss possible causes for the remarkable evolutionary changes in males and we conclude that this high diversity has been caused by sexual selection.

The Relative Importance of Sexual Dimorphism, Fluctuating Asymmetry, and Color Cues to Health during Evaluation of Potential Partners' Facial Photographs : A Conjoint Analysis Study.

PubMed

Mogilski, Justin K; Welling, Lisa L M

2017-03-01

Sexual dimorphism, symmetry, and coloration in human faces putatively signal information relevant to mate selection and reproduction. Although the independent contributions of these characteristics to judgments of attractiveness are well established, relatively few studies have examined whether individuals prioritize certain features over others. Here, participants (N = 542, 315 female) ranked six sets of facial photographs (3 male, 3 female) by their preference for starting long- and short-term romantic relationships with each person depicted. Composite-based digital transformations were applied such that each image set contained 11 different versions of the same identity. Each photograph in each image set had a unique combination of three traits: sexual dimorphism, symmetry, and color cues to health. Using conjoint analysis to evaluate participants' ranking decisions, we found that participants prioritized cues to sexual dimorphism over symmetry and color cues to health. Sexual dimorphism was also found to be relatively more important for the evaluation of male faces than for female faces, whereas symmetry and color cues to health were relatively more important for the evaluation of female faces than for male faces. Symmetry and color cues to health were more important for long-term versus short-term evaluations for female faces, but not male faces. Analyses of utility estimates reveal that our data are consistent with research showing that preferences for facial masculinity and femininity in male and female faces vary according to relationship context. These findings are interpreted in the context of previous work examining the influence of these facial attributes on romantic partner perception.

Humor Ability Reveals Intelligence, Predicts Mating Success, and Is Higher in Males

ERIC Educational Resources Information Center

Greengross, Gil; Miller, Geoffrey

2011-01-01

A good sense of humor is sexually attractive, perhaps because it reveals intelligence, creativity, and other "good genes" or "good parent" traits. If so, intelligence should predict humor production ability, which in turn should predict mating success. In this study, 400 university students (200 men and 200 women) completed…

The biological basis of human sexual orientation: is there a role for epigenetics?

PubMed

Ngun, Tuck C; Vilain, Eric

2014-01-01

Sexual orientation is one of the largest sex differences in humans. The vast majority of the population is heterosexual, that is, they are attracted to members of the opposite sex. However, a small but significant proportion of people are bisexual or homosexual and experience attraction to members of the same sex. The origins of the phenomenon have long been the subject of scientific study. In this chapter, we will review the evidence that sexual orientation has biological underpinnings and consider the involvement of epigenetic mechanisms. We will first discuss studies that show that sexual orientation has a genetic component. These studies show that sexual orientation is more concordant in monozygotic twins than in dizygotic ones and that male sexual orientation is linked to several regions of the genome. We will then highlight findings that suggest a link between sexual orientation and epigenetic mechanisms. In particular, we will consider the case of women with congenital adrenal hyperplasia (CAH). These women were exposed to high levels of testosterone in utero and have much higher rates of nonheterosexual orientation compared to non-CAH women. Studies in animal models strongly suggest that the long-term effects of hormonal exposure (such as those experienced by CAH women) are mediated by epigenetic mechanisms. We conclude by describing a hypothetical framework that unifies genetic and epigenetic explanations of sexual orientation and the continued challenges facing sexual orientation research. Copyright © 2014 Elsevier Inc. All rights reserved.

A review of human male field studies of hormones and behavioral reproductive effort.

PubMed

Gray, Peter B; McHale, Timothy S; Carré, Justin M

2017-05-01

The purpose of this paper is to review field studies of human male hormones and reproductive behavior. We first discuss life history theory and related conceptual considerations. As illustrations, distinctive features of human male life histories such as coalitional aggression, long-term partnering and paternal care are noted, along with their relevance to overall reproductive effort and developmental plasticity. We address broad questions about what constitutes a human male field study of hormones and behavior, including the kinds of hormone and behavioral measures employed in existing studies. Turning to several sections of empirical review, we present and discuss evidence for links between prenatal and juvenile androgens and sexual attraction and aggression. This includes the proposal that adrenal androgens-DHEA and androstenedione-may play functional roles during juvenility as part of a life-stage specific system. We next review studies of adult male testosterone responses to competition, with these studies emphasizing men's involvement in individual and team sports. These studies show that men's testosterone responses differ with respect to variables such as playing home/away, winning/losing, and motivation. Field studies of human male hormones and sexual behavior also focus on testosterone, showing some evidence of patterned changes in men's testosterone to sexual activity. Moreover, life stage-specific changes in male androgens may structure age-related differences in sexual behavior, including decreases in sexual behavior with senescence. We overview the considerable body of research on male testosterone, partnerships and paternal care, noting the variation in social context and refinements in research design. A few field studies provide insight into relationships between partnering and paternal behavior and prolactin, oxytocin, and vasopressin. In the third section of the review, we discuss patterns, limitations and directions for future research. This includes discussion of conceptual and methodological issues future research might consider as well as opportunities for contributions in under-researched male life stages (juvenility, senescence) and hormones (e.g., vasopressin). Copyright © 2016 Elsevier Inc. All rights reserved.

The complex interplay of sex allocation and sexual selection.

PubMed

Booksmythe, Isobel; Schwanz, Lisa E; Kokko, Hanna

2013-03-01

It is well recognized that sex allocation strategies can be influenced by sexual selection, when females adjust offspring sex ratios in response to their mates' attractiveness. Yet the reciprocal influence of strategic sex allocation on processes of sexual selection has only recently been revealed. Recent theoretical work demonstrates that sex allocation weakens selection for female preferences, leading to the decline of male traits. However, these results have been derived assuming that females have perfect knowledge of mate attractiveness and precise control over cost-free allocation. Relaxing these assumptions highlights the importance of another feedback: that adaptive sex allocation must become difficult to maintain as traits and preferences decline. When sex allocation strategies erode not only traits and preferences but also their own selective advantage, predictions can no longer be expressed as a simple linear correlation between ornament exaggeration and adaptive sex allocation. Instead, strongest sex ratio biases may be found at intermediate trait levels. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Approach and Avoidance Tendencies Toward Picture Stimuli of (Pre-)Pubescent Children and Adults: An Investigation in Pedophilic and Nonpedophilic Samples.

PubMed

Weidacker, K; Kärgel, C; Massau, C; Weiß, S; Kneer, J; Krueger, T H C; Schiffer, B

2017-03-01

The presence of pedophilic sexual interests is considered of high importance for predicting recidivism among individuals who have committed sexual offenses. However, objective and valid assessment methods that are robust against confounding issues such as cognitive capacity and manipulation are sparse. We applied the Approach-Avoidance Task (AAT) for detecting sexual interests in 38 pedophilic men (18 primarily attracted to boys) and 27 male nonpedophilic (11 gay) participants. The AAT relies on automatic approach and avoidance tendencies, independent of cognitive abilities such as memory capacity and intelligence. Approach-avoidance tendencies toward stimuli depicting seminude prepubescent boys and girls as well as men and women are reported. The results were consistent with previous research on the utility of the AAT: Except for pedophiles attracted to girls, the mean AAT scores (approach minus avoidance reaction time for each stimulus category) were positive only for stimuli of the preferred category. A multivariate binary logistic regression approach revealed 80% overall accuracy in differentiating pedophilic from nonpedophilic participants.

Transgender transitioning and change of self-reported sexual orientation.

PubMed

Auer, Matthias K; Fuss, Johannes; Höhne, Nina; Stalla, Günter K; Sievers, Caroline

2014-01-01

Sexual orientation is usually considered to be determined in early life and stable in the course of adulthood. In contrast, some transgender individuals report a change in sexual orientation. A common reason for this phenomenon is not known. We included 115 transsexual persons (70 male-to-female "MtF" and 45 female-to-male "FtM") patients from our endocrine outpatient clinic, who completed a questionnaire, retrospectively evaluating the history of their gender transition phase. The questionnaire focused on sexual orientation and recalled time points of changes in sexual orientation in the context of transition. Participants were further asked to provide a personal concept for a potential change in sexual orientation. In total, 32.9% (n = 23) MtF reported a change in sexual orientation in contrast to 22.2% (n = 10) FtM transsexual persons (p = 0.132). Out of these patients, 39.1% (MtF) and 60% (FtM) reported a change in sexual orientation before having undergone any sex reassignment surgery. FtM that had initially been sexually oriented towards males ( = androphilic), were significantly more likely to report on a change in sexual orientation than gynephilic, analloerotic or bisexual FtM (p = 0.012). Similarly, gynephilic MtF reported a change in sexual orientation more frequently than androphilic, analloerotic or bisexual MtF transsexual persons (p =0.05). In line with earlier reports, we reveal that a change in self-reported sexual orientation is frequent and does not solely occur in the context of particular transition events. Transsexual persons that are attracted by individuals of the opposite biological sex are more likely to change sexual orientation. Qualitative reports suggest that the individual's biography, autogynephilic and autoandrophilic sexual arousal, confusion before and after transitioning, social and self-acceptance, as well as concept of sexual orientation itself may explain this phenomenon.

Transgender Transitioning and Change of Self-Reported Sexual Orientation

PubMed Central

Höhne, Nina; Stalla, Günter K.; Sievers, Caroline

2014-01-01

Objective Sexual orientation is usually considered to be determined in early life and stable in the course of adulthood. In contrast, some transgender individuals report a change in sexual orientation. A common reason for this phenomenon is not known. Methods We included 115 transsexual persons (70 male-to-female “MtF” and 45 female-to-male “FtM”) patients from our endocrine outpatient clinic, who completed a questionnaire, retrospectively evaluating the history of their gender transition phase. The questionnaire focused on sexual orientation and recalled time points of changes in sexual orientation in the context of transition. Participants were further asked to provide a personal concept for a potential change in sexual orientation. Results In total, 32.9% (n =  23) MtF reported a change in sexual orientation in contrast to 22.2% (n =  10) FtM transsexual persons (p =  0.132). Out of these patients, 39.1% (MtF) and 60% (FtM) reported a change in sexual orientation before having undergone any sex reassignment surgery. FtM that had initially been sexually oriented towards males ( = androphilic), were significantly more likely to report on a change in sexual orientation than gynephilic, analloerotic or bisexual FtM (p  =  0.012). Similarly, gynephilic MtF reported a change in sexual orientation more frequently than androphilic, analloerotic or bisexual MtF transsexual persons (p  =  0.05). Conclusion In line with earlier reports, we reveal that a change in self-reported sexual orientation is frequent and does not solely occur in the context of particular transition events. Transsexual persons that are attracted by individuals of the opposite biological sex are more likely to change sexual orientation. Qualitative reports suggest that the individual's biography, autogynephilic and autoandrophilic sexual arousal, confusion before and after transitioning, social and self-acceptance, as well as concept of sexual orientation itself may explain this phenomenon. PMID:25299675

Males of a Strongly Polygynous Species Consume More Poisonous Food than Females

PubMed Central

Bravo, Carolina; Bautista, Luis Miguel; García-París, Mario; Blanco, Guillermo; Alonso, Juan Carlos

2014-01-01

We present evidence of a possible case of self-medication in a lekking bird, the great bustard Otis tarda. Great bustards consumed blister beetles (Meloidae), in spite of the fact that they contain cantharidin, a highly toxic compound that is lethal in moderate doses. In addition to anthelminthic properties, cantharidin was effective against gastrointestinal bacteria that cause sexually-transmitted diseases. Although both sexes consumed blister beetles during the mating season, only males selected them among all available insects, and ingested more and larger beetles than females. The male-biased consumption suggests that males could use cantharidin to reduce their parasite load and increase their sexual attractiveness. This plausibly explains the intense cloaca display males perform to approaching females, and the meticulous inspection females conduct of the male's cloaca, a behaviour only observed in this and another similar species of the bustard family. A white, clean cloaca with no infection symptoms (e.g., diarrhoea) is an honest signal of both, resistance to cantharidin and absence of parasites, and represents a reliable indicator of the male quality to the extremely choosy females. Our results do not definitely prove, but certainly strongly suggest that cantharidin, obtained by consumption of blister beetles, acts in great bustards as an oral anti-microbial and pathogen-limiting compound, and that males ingest these poisonous insects to increase their mating success, pointing out that self-medication might have been overlooked as a sexually-selected mechanism enhancing male fitness. PMID:25337911

Clinical characteristics of patients with gender identity disorder at a Japanese gender identity disorder clinic.

PubMed

Okabe, Nobuyuki; Sato, Toshiki; Matsumoto, Yosuke; Ido, Yumiko; Terada, Seishi; Kuroda, Shigetoshi

2008-01-15

The aim of this study was to examine the clinical characteristics of patients with gender identity disorder (GID) at a GID clinic in Japan. A total of 603 consecutive patients were evaluated at the GID clinic using clinical information and results of physical and neurological examinations. Using DSM-IV criteria, 579 patients (96.0%) were diagnosed with GID. Four patients were excluded for transvestic fetishism, eight for homosexuality, five for schizophrenia, three for personality disorders, and four for other psychiatric disorders. Among the GID patients, 349 (60.3%) were the female-to-male (FTM) type, and 230 (39.7%) were the male-to-female (MTF) type. Almost all FTM-type GID patients started to feel discomfort with their sex before puberty and were sexually attracted to females. The proportion of FTM patients who had experienced marriage as a female was very low, and very few had children. Therefore, FTM-type GID patients seem to be highly homogeneous. On the other hand, various patterns of age at onset and sexual attraction existed among MTF patients. Among the MTF-type GID patients, 28.3% had married as males and 18.7% had sired children. Thus, MTF-type GID patients seem to be more heterogeneous.

Status epilepticus during early development disrupts sexual behavior in adult female rats: recovery with sexual experience.

PubMed

Coria-Avila, Genaro Alfonso; Paredes-Ramos, Pedro; Galán, Ricardo; Herrera-Covarrubias, Deissy; López-Meraz, Maria-Leonor

2014-05-01

Female sexual behavior is sensitive to stress and diseases. Some studies have shown that status epilepticus (SE) can affect sexual proceptivity and receptivity in female rats and also increases reject responses towards males. However, epidemiologic studies indicate that SE is more frequent in young individuals. Herein, we assessed the effects of SE in infant females on their sexual behavior during adulthood. Thirteen-day-old (P13) rat pups received intraperitoneal injections of lithium chloride (3 mEq/kg). Twenty hours later, at P14, SE was induced by subcutaneous injection of pilocarpine hydrochloride (100 mg/kg s.c.). Control animals were given an equal volume of saline subcutaneously. The animals were weaned at P21 and, later in adulthood, were ovariectomized and hormone-primed with estradiol+progesterone, and their sexual behavior assessed during 4 separate trials of 30 min each with a stud male. Our results indicate that proceptive behaviors (solicitations and hops and darts) were impaired during the first trial, but no alterations were observed for receptivity and attractivity. By trial 3, all SE females displayed normal proceptivity. These results indicate that SE in infancy readily affects proceptivity in a reversible manner. We discuss the role of sexual experience in recovery. Copyright © 2014 Elsevier Inc. All rights reserved.

Masculinity-femininity predicts sexual orientation in men but not in women.

PubMed

Udry, J Richard; Chantala, Kim

2006-11-01

Using the nationally representative sample of about 15,000 Add Health respondents in Wave III, the hypothesis is tested that masculinity-femininity in adolescence is correlated with sexual orientation 5 years later and 6 years later: that is, that for adolescent males in 1995 and again in 1996, more feminine males have a higher probability of self-identifying as homosexuals in 2001-02. It is predicted that for adolescent females in 1995 and 1996, more masculine females have a higher probability of self-identifying as homosexuals in 2001-02. Masculinity-femininity is measured by the classical method used by Terman & Miles. For both time periods, the hypothesis was strongly confirmed for males: the more feminine males had several times the probability of being attracted to same-sex partners, several times the probability of having same-sex partners, and several times the probability of self-identifying as homosexuals, compared with more masculine males. For females, no relationship was found at either time period between masculinity and sex of preference. The biological mechanism underlying homosexuality may be different for males and females.

Effects of Methyl Eugenol Feeding on Mating Compatibility of Asian Population of Bactrocera dorsalis (Diptera: Tephritidae) with African Population and with B. carambolae

PubMed Central

Haq, Ihsan ul; Vreysen, Marc J. B.; Schutze, Mark; Hendrichs, Jorge; Shelly, Todd

2016-01-01

Males of some species included in the Bactrocera dorsalis complex are strongly attracted to methyl eugenol (ME) (1,2-dimethoxy-4-(2-propenyl) benzene), a natural compound occurring in a variety of plant species. ME feeding of males of the B. dorsalis complex is known to enhance their mating competitiveness. Within B. dorsalis, recent studies show that Asian and African populations of B. dorsalis are sexually compatible, while populations of B. dorsalis and Bactrocera carambolae are relatively incompatible. The objectives of this study were to examine whether ME feeding by males affects mating compatibility between Asian and African populations of B. dorsalis and ME feeding reduces male mating incompatibility between B. dorsalis (Asian population) and B. carambolae. The data confirmed that Asian and African populations of B. dorsalis are sexually compatible for mating and showed that ME feeding only increased the number of matings. Though ME feeding also increased the number of matings of B. dorsalis (Asian population) and B. carambolae males but the sexual incompatibility between both species was not reduced by treatment with ME. These results conform to the efforts resolving the biological species limits among B. dorsalis complex and have implications for fruit fly control programs in fields and horticultural trade. PMID:26362991

Self-Reported Changes in Attractions and Social Determinants of Mental Health in Transgender Adults.

PubMed

Katz-Wise, Sabra L; Reisner, Sari L; White Hughto, Jaclyn M; Budge, Stephanie L

2017-07-01

This study examined associations between changes in self-reported attractions and mental health in a community-based sample of self-identified transgender adults. Participants were purposively recruited in 2013 using bimodal sampling methods and completed a one-time survey. Multivariable logistic regression models estimated adjusted risk ratios and 95 % confidence intervals to examine associations between changes in attractions and mental health outcomes (lifetime self-harm, suicide attempts, depression diagnosis; past-week clinically significant depressive distress assessed via CES-D 10) among the entire sample (N = 452; 285 female-to-male spectrum, 167 male-to-female spectrum) and after gender transition among those who had socially transitioned (n = 205; 156 female-to-male spectrum, 49 male-to-female spectrum). Models were adjusted for known population social determinants (age, race/ethnicity, gender identity, socioeconomic status, sexual orientation identity), transgender-specific determinants (age of transgender realization, social transition, medical transition, visual gender nonconformity, non-binary gender identification), and survey mode (online vs. in-person sampling). Lifetime changes in attractions were significantly associated with increased probability of all mental health outcomes; individuals reporting any change in attractions were more likely than individuals not reporting changes to indicate lifetime self-harm, suicide attempts, depression diagnosis, and current depressive distress (all ps < .05). Changes in attractions post-social transition were not significantly associated with mental health outcomes. Many, but not all, population and transgender-specific social determinants were significantly associated with mental health in the full sample and among those who had socially transitioned. Clinical implications of findings about changes in attractions and mental health are discussed for transgender individuals.

"Feeling frumpy": the relationships between body image and sexual response changes in midlife women.

PubMed

Koch, Patricia Barthalow; Mansfield, Phyllis Kernoff; Thurau, Debra; Carey, Molly

2005-08-01

This study investigated the relationships between self-rated attractiveness and self-reported sexual response changes (over the past decade) and current sexual satisfaction in 307 heterosexual, midlife women. Results indicated that regardless of the woman's specific age, she was more likely to consider herself more attractive when she was 10 years younger and her self-perceived attractiveness did not significantly differ based on her menopausal status. The more a woman perceived herself as less attractive than before, the more likely she was to report a decline in sexual desire or frequency of sexual activity. The more she perceived herself as attractive, the more likely she was to experience an increase in sexual desire, orgasm, enjoyment, or frequency of sexual activity. There were no significant statistical relationships between a woman's perception of her own attractiveness as she aged and her current sexual satisfaction.

Ultraviolet reflectance by the cere of raptors

PubMed Central

Mougeot, François; Arroyo, Beatriz E

2006-01-01

Ultraviolet (UV) signals have been shown to play key roles in social and sexual signalling in birds. Using a spectrophotometer, we analysed the colour of the cere (skin above the beak) of a diurnal raptor, the Montagu's harrier (Circus pygargus), and show that it reflects in the UV part of the spectrum. The cere is a well-known sexual signal in raptors, with carotenoid based pigmentation being indicative of quality. We thus hypothesized that UV reflectance also signals quality. Accordingly, we found that in our sample of wild males, the location of the UV peak was related to the orangeness of cere and correlated with male body mass and condition (mass corrected for size). Also, males with brighter UV were mated to females that laid earlier, as expected if UV reflectance relates to a male's quality and attractiveness. Future studies should investigate the relationships between UV reflectance and carotenoid pigmentation of cere, and test how UV reflectance influences mate choice. PMID:17148356

Adiposity, compared with masculinity, serves as a more valid cue to immunocompetence in human mate choice

PubMed Central

Rantala, Markus J.; Coetzee, Vinet; Moore, Fhionna R.; Skrinda, Ilona; Kecko, Sanita; Krama, Tatjana; Kivleniece, Inese; Krams, Indrikis

2013-01-01

According to the ‘good genes’ hypothesis, females choose males based on traits that indicate the male's genetic quality in terms of disease resistance. The ‘immunocompetence handicap hypothesis’ proposed that secondary sexual traits serve as indicators of male genetic quality, because they indicate that males can contend with the immunosuppressive effects of testosterone. Masculinity is commonly assumed to serve as such a secondary sexual trait. Yet, women do not consistently prefer masculine looking men, nor is masculinity consistently related to health across studies. Here, we show that adiposity, but not masculinity, significantly mediates the relationship between a direct measure of immune response (hepatitis B antibody response) and attractiveness for both body and facial measurements. In addition, we show that circulating testosterone is more closely associated with adiposity than masculinity. These findings indicate that adiposity, compared with masculinity, serves as a more important cue to immunocompetence in female mate choice. PMID:23193134

The Role of Bioacoustic Signals in Koala Sexual Selection: Insights from Seasonal Patterns of Associations Revealed with GPS-Proximity Units.

PubMed

Ellis, William; FitzGibbon, Sean; Pye, Geoff; Whipple, Bill; Barth, Ben; Johnston, Stephen; Seddon, Jenny; Melzer, Alistair; Higgins, Damien; Bercovitch, Fred

2015-01-01

Despite being a charismatic and well-known species, the social system of the koala (Phascolarctos cinereus--the only extant member of the family Phascolarctidae) is poorly known and much of the koala's sociality and mating behaviors remain un-quantified. We evaluated these using proximity logging-GPS enabled tracking collars on wild koalas and discuss their implications for the mating system of this species. The frequency and duration of male-female encounters increased during the breeding season, with male-male encounters quite uncommon, suggesting little direct mating competition. By comparison, female-female interactions were very common across both seasons. Body mass of males was not correlated with their interactions with females during the breeding season, although male size is associated with a variety of acoustic parameters indicating individuality. We hypothesise that vocal advertising reduces the likelihood of male-male encounters in the breeding season while increasing the rate of male-female encounters. We suggest that male mating-season bellows function to reduce physical confrontations with other males allowing them to space themselves apart, while, at the same time, attracting females. We conclude that indirect male-male competition, female mate choice, and possibly female competition, mediate sexual selection in koalas.

Male-Biased Sexual Size Dimorphism, Resource Defense Polygyny, and Multiple Paternity in the Emei Moustache Toad (Leptobrachium boringii)

PubMed Central

Hudson, Cameron M.; Fu, Jinzhong

2013-01-01

We tested the hypotheses that the Emei moustache toad (Leptobrachium boringii) exhibits resource defense polygyny and that combat led to the evolution of male-biased sexual size dimorphism. Between February and March of 2011 and 2012, 26 female and 55 male L. boringii from Mount Emei UNESCO World Heritage Site, Sichuan, China, were observed throughout the breeding season. Prior to the breeding season, males grow 10–16 keratinized maxillary nuptial spines, which fall off once the season has ended. Throughout this time, males construct and defend aquatic nests where they produce advertisement calls to attract females. In a natural setting, we documented 14 cases involving a total of 22 males where males used their moustaches for aggressive interaction, and nest takeover was observed on seven occasions. Males were also observed to possess injuries resulting from combat. Genetic analysis using microsatellite DNA markers revealed several cases of multiple paternity, both within nest and within clutch. This observation indicated that some alternative male reproductive strategy, such as satellite behaviour, is occurring, which may have led to the multiple paternity. Larger males were observed to mate more frequently, and in multiple nests, suggesting that females are selecting for larger males, or that larger males are more capable of defending high quality territories. PMID:23840725

Flirting with disaster: short-term mating orientation and hostile sexism predict different types of sexual harassment.

PubMed

Diehl, Charlotte; Rees, Jonas; Bohner, Gerd

2012-01-01

We combine evolutionary and sociocultural accounts of sexual harassment, proposing that sexuality-related and hostility-related motives lead to different types of harassment. Specifically, men's short-term mating orientation (STMO) was hypothesized to predict only unwanted sexual attention but not gender harassment, whereas men's hostile sexism (HS) was hypothesized to predict both unwanted sexual attention and gender harassment. As part of an alleged computer-chat task, 100 male students could send sexualized personal remarks (representing unwanted sexual attention), sexist jokes (representing gender harassment), or nonharassing material to an attractive female target. Independently, participants' STMO, HS, and sexual harassment myth acceptance (SHMA) were assessed. Correlational and path analyses revealed that STMO specifically predicted unwanted sexual attention, whereas HS predicted both unwanted sexual attention and gender harassment. Furthermore, SHMA fully mediated the effect of HS on gender harassment, but did not mediate effects of STMO or HS on unwanted sexual attention. Results are discussed in relation to motivational explanations for sexual harassment and antiharassment interventions. © 2012 Wiley Periodicals, Inc.

Unattractive, promiscuous and heavy drinkers: perceptions of women with tattoos.

PubMed

Swami, Viren; Furnham, Adrian

2007-12-01

This study examined social and physical perceptions of blonde and brunette women with different degrees of tattooing. Eighty-four female and 76 male undergraduates rated a series of 16 female line drawings that varied in 2 levels of hair colour and 8 levels of tattooing. Ratings were made for physical attractiveness and sexual promiscuity, as well as estimates of the number of alcohol units consumed on a typical night out. Results showed that tattooed women were rated as less physically attractive, more sexually promiscuous and heavier drinkers than untattooed women, with more negative ratings with increasing number of tattoos. There were also weak interactions between body art and hair colour, with blonde women in general rated more negatively than brunettes. Results are discussed in terms of stereotypes about women who have tattoos and the effects of such stereotypes on well-being.

Neuroanatomical dichotomy of sexual behaviors in rodents: a special emphasis on brain serotonin.

PubMed

Angoa-Pérez, Mariana; Kuhn, Donald M

2015-09-01

Much of the social behavior in which rodents engage is related to reproduction, such as maintaining a breeding territory, seeking mates, mating, and caring for their young. Rodents belong to the internally fertilizing species that require sexual behavior for reproduction. The dyadic, heterosexual patterns of most mammalian species are sexually dimorphic, but they also share mutual components in both sexes: sexual attraction is reciprocal, sexual initiative is assumed, appetitive behavior is engaged in, and mating involves consummatory and postconsummatory phases in females as well as in males. Serotonin, a phylogenetically ancient molecule, is the most widely distributed neurotransmitter in the brain and its signaling pathways are essential for numerous functions including sexual behavior. Since the late 1960s, brain serotonergic neurotransmission has been considered to exert an inhibitory influence on the neural mechanisms mediating sexual behavior. This contention was based mainly on the observations that a decrease in central serotonergic activity facilitated the elicitation of sexual behavior, whereas an increase in central serotonergic activity attenuated it. However, the discovery of over 14 types of serotonin receptors has added numerous layers of complexity to the study of serotonin and sexual behavior. Evidence shows that, upon activation, certain receptor subtypes facilitate, whereas some others suppress, sexual behavior, as well as sexual arousal and motivation. Furthermore, the role of these receptors has been shown to be different in the male and female sexes. The use of serotonergic pharmacological interventions, mouse strains with genetic polymorphisms causing alterations in the levels of brain serotonin, and animal models with genetic manipulations of various serotonin effectors has helped delineate the fundamental role of this neurotransmitter in the regulation of sexual behavior. This review aims to examine the basics of the components of female and male sexual behavior and the participation of the serotonin system in the modulation of these behaviors, with emphasis on rodents.

Neuroanatomical dichotomy of sexual behaviors in rodents: a special emphasis on brain serotonin

PubMed Central

Angoa-Pérez, Mariana; Kuhn, Donald M.

2016-01-01

Much of the social behavior in which rodents engage is related to reproduction, such as maintaining a breeding territory, seeking mates, mating, and caring for young. Rodents belong to the internally fertilizing species that require sexual behavior for reproduction. The dyadic, heterosexual patterns of most mammalian species are sexually dimorphic, but they also share mutual components in both sexes: sexual attraction is reciprocal, sexual initiative is assumed, appetitive behavior is engaged in and mating involves consummatory and postconsummatory phases in females as well as in males. Serotonin, a phylogenetically ancient molecule, is the most widely distributed neurotransmitter in the brain and its signaling pathways are essential for numerous functions including sexual behavior. Since the late 1960’s, brain serotonergic neurotransmission has been considered to exert an inhibitory influence on the neural mechanisms mediating sexual behavior. This contention was based mainly on the observations that a decrease in central serotonergic activity facilitated the elicitation of sexual behavior while an increase in central serotonergic activity attenuated it. However, the discovery of over 14 types of serotonin receptors has added numerous layers of complexity to the study of serotonin and sexual behavior. Evidence shows that upon activation, certain receptor subtypes facilitate while some others suppress sexual behavior as well as sexual arousal and motivation. Furthermore, the role of these receptors has been shown to be differential in males versus females. The use of serotonergic pharmacological interventions, mouse strains with genetic polymorphisms causing alterations in the levels of brain serotonin as well as animal models with genetic manipulations of various serotonin effectors has helped delineate the fundamental role of this neurotransmitter in the regulation of sexual behavior. This review aims to examine the basics of the components of female and male sexual behavior and the participation of the serotonin system in the modulation of these behaviors with emphasis on rodents. PMID:26110223

"All of My Lovers Fit Into This Scale": Sexual Minority Individuals' Responses to Two Novel Measures of Sexual Orientation.

PubMed

Galupo, M Paz; Lomash, Edward; Mitchell, Renae C

2017-01-01

Previous qualitative research on traditional measures of sexual orientation raise concerns regarding how well these scales capture sexual minority individuals' experience of sexuality. The present research focused on the critique of two novel scales developed to better capture the way sexual and gender minority individuals conceptualize sexuality. Participants were 179 sexual minority (i.e., gay, lesbian, bisexual, pansexual, queer, asexual) individuals who identified as cisgender (n = 122) and transgender (n = 57). Participants first completed the new scales, then provided qualitative responses regarding how well each scale captured their sexuality. The Sexual-Romantic Scale enabled the measurement of sexual and romantic attraction to each sex independently (same-sex and other-sex). Participants resonated with the way the Sexual-Romantic scale disaggregated sexual and romantic attraction. Although cisgender monosexual (lesbian/gay) individuals positively responded to the separation of same- and other-sex attraction, individuals with either plurisexual (bisexual, pansexual, or fluid) or transgender identities found the binary conceptualization of sex/gender problematic. The Gender-Inclusive Scale incorporated same- and other-sex attraction as well as dimensions of attraction beyond those based on sex (attraction to masculine, feminine, androgynous, and gender non-conforming individuals). The incorporation of dimensions of sexual attraction outside of sex in the Gender-Inclusive Scale was positively regarded by participants of all identities. Findings indicate that the Sexual-Romantic and Gender-Inclusive scales appear to address some of the concerns raised in previous research regarding the measurement of sexual orientation among sexual minority individuals.

Voice correlates of mating success in men: examining "contests" versus "mate choice" modes of sexual selection.

PubMed

Hodges-Simeon, Carolyn R; Gaulin, Steven J C; Puts, David A

2011-06-01

Men's copulatory success can often be predicted by measuring traits involved in male contests and female choice. Previous research has demonstrated relationships between one such vocal trait in men, mean fundamental frequency (F(0)), and the outcomes and indicators of sexual success with women. The present study investigated the role of another vocal parameter, F(0) variation (the within-subject SD in F(0) across the utterance, F(0)-SD), in predicting men's reported number of female sexual partners in the last year. Male participants (N = 111) competed with another man for a date with a woman. Recorded interactions with the competitor ("competitive recording") and the woman ("courtship recording") were analyzed for five non-linguistic vocal parameters: F(0)-SD, mean F(0), intensity, duration, and formant dispersion (D( f ), an acoustic correlate of vocal tract length), as well as dominant and attractive linguistic content. After controlling for age and attitudes toward uncommitted sex (SOI), lower F(0)-SD (i.e., a more monotone voice) and more dominant linguistic content were strong predictors of the number of past-year sexual partners, whereas mean F(0) and D( f ) did not significantly predict past-year partners. These contrasts have implications for the relative importance of male contests and female choice in shaping men's mating success and hence the origins and maintenance of sexually dimorphic traits in humans.

Sex-specific consequences of an induced immune response on reproduction in a moth.

PubMed

Barthel, Andrea; Staudacher, Heike; Schmaltz, Antje; Heckel, David G; Groot, Astrid T

2015-12-16

Immune response induction benefits insects in combatting infection by pathogens. However, organisms have a limited amount of resources available and face the dilemma of partitioning resources between immunity and other life-history traits. Since males and females differ in their life histories, sex-specific resource investment strategies to achieve an optimal immune response following an infection can be expected. We investigated immune response induction of females and males of Heliothis virescens in response to the entomopathogenic bacterium Serratia entomophila, and its effects on mating success and the female sexual signal. We found that females had higher expression levels of immune-related genes after bacterial challenge than males. However, males maintained a higher baseline expression of immune-related genes than females. The increased investment in immunity of female moths was negatively correlated with mating success and the female sexual signal. Male mating success was unaffected by bacterial challenge. Our results show that the sexes differed in their investment strategies: females invested in immune defense after a bacterial challenge, indicating facultative immune deployment, whereas males had higher baseline immunity than females, indicating immune maintenance. Interestingly, these differences in investment were reflected in the mate choice assays. As female moths are the sexual signallers, females need to invest resources in their attractiveness. However, female moths appeared to invest in immunity at the cost of reproductive effort.

Avatars with Sex Appeal as Pedagogical Agents: Attractiveness, Trustworthiness, Expertise, and Gender Differences

ERIC Educational Resources Information Center

Wang, Chih-Chien; Yeh, Wei-Jyh

2013-01-01

The study focused on the use of pedagogical agents with sex appeal in a computer-assisted learning environment. The study adopted a 2 (male/female) × 3 (demure/seductive/overtly sexual) experimental design. The primary analysis consisted of 2 parts: (a) comparing the impact of effective learning on students' perceptions of demure, seductive, or…

When Sexual and Religious Orientation Collide: Considerations in Working with Conflicted Same-Sex Attracted Male Clients

ERIC Educational Resources Information Center

Haldeman, Douglas C.

2004-01-01

The debate among scholars and gay activists and religious/political activists about the appropriateness and efficacy of conversion therapy has left out a number of individuals for whom neither gay-affirmative nor conversion therapy may be indicated. The present discussion, through the use of case material, offers considerations for the…

Mate choice trade-offs and women's preference for physically attractive men.

PubMed

Waynforth, D

2001-09-01

Researchers studying human sexuality have repeatedly concluded that men place more emphasis on the physical attractiveness of potential mates than women do, particularly in long-term sexual relationships. Evolutionary theorists have suggested that this is the case because male mate value (the total value of the characteristics that an individual possesses in terms of the potential contribution to his or her mate's reproductive success) is better predicted by social status and economic resources, whereas women's mate value hinges on signals conveyed by their physical appearance. This pattern may imply that women trade off attractiveness for resources in mate choice. Here I test whether a trade-off between resources and attractiveness seems to be occurring in the mate choice decisions of women in the United States. In addition, the possibility that the risk of mate desertion drives women to choose less attractive men as long-term mates is tested. The results were that women rated physically attractive men as more likely to cheat or desert a long-term relationship, whereas men did not consider attractive women to be more likely to cheat. However, women showed no aversion to the idea of forming long-term relationships with attractive men. Evidence for a trade-off between resources and attractiveness was found for women, who traded off attractiveness, but not other traits, for resources. The potential meaning of these findings, as well as how they relate to broader issues in the study of sex differences in the evolution of human mate choice for physical traits, is discussed.

Should Attractive Males Sneak: The Trade-Off between Current and Future Offspring

PubMed Central

Candolin, Ulrika; Vlieger, Leon

2013-01-01

Alternative reproductive tactics are predicted to be adopted by less competitive males when competition for fertilization is intense. Yet, in some species, competitively superior males use an alternative tactic alongside the conventional tactic. This can jeopardize their success through the conventional tactic, but surprisingly little attention has been paid to this cost. We investigated 1) the degree to which competitive males sneak fertilize eggs in the polygamous threespine stickleback, Gasterosteus aculeatus, and 2) if males balance the cost of sneaking against its benefit. We found competitive males that succeeded in establishing a territory and in attracting spawning females to perform most sneak fertilizations. However, when we reduced the benefit of sneak attempts, by reducing visibility and the success rate of sneak attempts, males sneaked less. When we increased the cost of sneak attempts, by increasing the perceived value of current offspring (by mating males to preferred females rather than unpreferred females or no females), the interest of males in sneak opportunities decreased. Intriguingly, larger males, who presumably had a higher probability of future reproduction, were more willing to risk their current offspring for sneak opportunities. These findings suggest that competitive males that are attractive to females carefully balance costs against benefits in their sneaking decisions. More broadly, our results imply that changes in the environment can influence the cost-benefit ratio of sneaking and alter the distribution of fertilizations in a population. We end with discussing the implications that alterations in sneaking behavior could have for the operation of sexual selection in changing environments. PMID:23516423

Is there a role for amplifiers in sexual selection?

PubMed

Gualla, Filippo; Cermelli, Paolo; Castellano, Sergio

2008-05-21

The amplifier hypothesis states that selection could favour the evolution of traits in signallers that improve the ability of receivers to extract honest information from other signals or cues. We provide a formal definition of amplifiers based on the receiver's mechanisms of signal perception and we present a game-theoretical model in which males advertise their quality and females use sequential-sampling tactics to choose among prospective mates. The main effect of an amplifier on the female mating strategy is to increase her mating threshold, making the female more selective as the effectiveness of the amplifier increases. The effects of the amplifier on male advertising strategy depends both on the context and on the types of the amplifier involved. We consider two different contexts for the evolution of amplifiers (when the effect of amplifiers is on signals and when it is on cues) and two types of amplifiers (the 'neutral amplifier', when it improves quality assessment without altering male attractiveness, and the 'attractive amplifier', when it improves both quality assessment and male attractiveness). The game-theoretical model provides two main results. First, neutral and attractive amplifiers represent, respectively, a conditional and an unconditional signalling strategy. In fact, at the equilibrium, neutral amplifiers are displayed only by males whose advertising level lays above the female acceptance threshold, whereas attractive amplifiers are displayed by all signalling males, independent of their quality. Second, amplifiers of signals increase the differences in advertising levels between amplifying and not-amplifying males, but they decrease the differences within each group, so that the system converges towards an 'all-or-nothing' signalling strategy. By applying concepts from information theory, we show that the increase in information transfer at the perception level due to the amplifier of signals is contrasted by a decrease in information transfer at the emitter level due to the increased stereotypy of male advertising strategy.

Becoming what we love: autogynephilic transsexualism conceptualized as an expression of romantic love.

PubMed

Lawrence, Anne A

2007-01-01

The increasing prevalence of male-to-female (MtF) transsexualism in Western countries is largely due to the growing number of MtF transsexuals who have a history of sexual arousal with cross-dressing or cross-gender fantasy. Ray Blanchard proposed that these transsexuals have a paraphilia he called autogynephilia, which is the propensity to be sexually aroused by the thought or image of oneself as female. Autogynephilia defines a transsexual typology and provides a theory of transsexual motivation, in that Blanchard proposed that MtF transsexuals are either sexually attracted exclusively to men (homosexual) or are sexually attracted primarily to the thought or image of themselves as female (autogynephilic), and that autogynephilic transsexuals seek sex reassignment to actualize their autogynephilic desires. Despite growing professional acceptance, Blanchard's formulation is rejected by some MtF transsexuals as inconsistent with their experience. This rejection, I argue, results largely from the misconception that autogynephilia is a purely erotic phenomenon. Autogynephilia can more accurately be conceptualized as a type of sexual orientation and as a variety of romantic love, involving both erotic and affectional or attachment-based elements. This broader conception of autogynephilia addresses many of the objections to Blanchard's theory and is consistent with a variety of clinical observations concerning autogynephilic MtF transsexualism.

Chemical and visual communication during mate searching in rock shrimp.

PubMed

Díaz, Eliecer R; Thiel, Martin

2004-06-01

Mate searching in crustaceans depends on different communicational cues, of which chemical and visual cues are most important. Herein we examined the role of chemical and visual communication during mate searching and assessment in the rock shrimp Rhynchocinetes typus. Adult male rock shrimp experience major ontogenetic changes. The terminal molt stages (named "robustus") are dominant and capable of monopolizing females during the mating process. Previous studies had shown that most females preferably mate with robustus males, but how these dominant males and receptive females find each other is uncertain, and is the question we examined herein. In a Y-maze designed to test for the importance of waterborne chemical cues, we observed that females approached the robustus male significantly more often than the typus male. Robustus males, however, were unable to locate receptive females via chemical signals. Using an experimental set-up that allowed testing for the importance of visual cues, we demonstrated that receptive females do not use visual cues to select robustus males, but robustus males use visual cues to find receptive females. Visual cues used by the robustus males were the tumults created by agitated aggregations of subordinate typus males around the receptive females. These results indicate a strong link between sexual communication and the mating system of rock shrimp in which dominant males monopolize receptive females. We found that females and males use different (sex-specific) communicational cues during mate searching and assessment, and that the sexual communication of rock shrimp is similar to that of the American lobster, where females are first attracted to the dominant males by chemical cues emitted by these males. A brief comparison between these two species shows that female behaviors during sexual communication contribute strongly to the outcome of mate searching and assessment.

Handgrip Strength as a Darwinian Fitness Indicator in Men

PubMed Central

Gallup, Andrew C.; Fink, Bernhard

2018-01-01

Handgrip strength (HGS) is a robust measure of overall muscular strength and function, and has long been predictive of a multitude of health factors and physical outcomes for both men and women. The fact that HGS represents such a ubiquitous measure of health and vitality may reflect the significance of this trait during human evolution. This trait is also highly sexually dimorphic due to influences of androgenic hormones and fat-free body mass, suggesting that it has been further elaborated through sexual selection. Consistent with this view, research within evolutionary psychology and related fields has documented distinct relationships between HGS and measures of social and sexual behavior, especially in men. Here, we review studies across different societies and cultural contexts showing that male HGS predicts measures of aggression and social dominance, perceived formidability, male-typical body morphology and movement, courtship display, physical attractiveness, and sexual behavior and reproductive fitness. These findings underscore the value of including HGS as an independent measure within studies examining human sexual selection, and corroborate existing research suggesting that specific features of physical strength have and continue to be under positive directional selection in men. PMID:29681871

Predator experience overrides learned aversion to heterospecifics in stickleback species pairs

PubMed Central

Kozak, Genevieve M.; Boughman, Janette W.

2015-01-01

Predation risk can alter female mating decisions because the costs of mate searching and selecting attractive mates increase when predators are present. In response to predators, females have been found to plastically adjust mate preference within species, but little is known about how predators alter sexual isolation and hybridization among species. We tested the effects of predator exposure on sexual isolation between benthic and limnetic threespine sticklebacks (Gasterosteus spp.). Female discrimination against heterospecific mates was measured before and after females experienced a simulated attack by a trout predator or a control exposure to a harmless object. In the absence of predators, females showed increased aversion to heterospecifics over time. We found that predator exposure made females less discriminating and precluded this learned aversion to heterospecifics. Benthic and limnetic males differ in coloration, and predator exposure also affected sexual isolation by weakening female preferences for colourful males. Predator effects on sexual selection were also tested but predators had few effects on female choosiness among conspecific mates. Our results suggest that predation risk may disrupt the cognitive processes associated with mate choice and lead to fluctuations in the strength of sexual isolation between species. PMID:25808887

The association of sexual orientation with self-rated health, and cigarette and alcohol use in Mexican adolescents and youths.

PubMed

Ortiz-Hernández, Luis; Tello, Blanca Lilia Gómez; Valdés, Jesús

2009-07-01

Evidence of health inequities associated with sexual orientation has been gathered for industrialized countries. The situation for lesbians, gay males, and bisexuals (LGB) from middle- or low-income countries may be worse than those in industrialized nations. Here, we analyze the relationship of sexual orientation with self-rated health and cigarette and alcohol use among a representative sample of Mexican adolescents and youths between the ages of 12 and 29 years, in order to explore whether this association is mediated by discrimination and violence. Three dimensions of sexual orientation (affective attraction, sexual behavior, and identity) were assessed. The outcomes were self-rated health and cigarette and alcohol use. Compared to heterosexuals, LGB youths more frequently smoked >or=6 cigarettes per day, reported having experienced family violence, having crimes perpetrated against them, and having experienced violations of their rights. Among males, gays and bisexuals exhibited a higher risk of poor health than heterosexuals. Compared to heterosexual women, lesbians and bisexual women were more likely to consume alcohol. Many differences in self-rated health and substance use according to sexual orientation were explained by having experienced discrimination and violence. We concluded that lesbian and bisexual females have a higher prevalence of cigarette and alcohol use. It is necessary to develop policies and programs aimed at the reduction of substance abuse among LGB youths (focusing on females who engage in sexual contact with persons of the same gender) and to work against discrimination and violence experienced by LGB people, particularly against non-heterosexual males.

[Sexual attraction: a concept analysis using an evolutionary perspective].

PubMed

Yang, Shu-Chin; Chu, Chun-Hong; Lu, Zxy-Yann Jane

2015-02-01

Medical technology has transformed the body image of women and altered perceptions of beauty and sexual attraction. While "sexual attraction" is a fundamental concept in sexology, the characteristics of this concept have not been studied in the field of nursing. Because nurses provide advice and health education for women, it is essential to clarify the concept of sexual attraction for the benefit of related nursing research and for the further development of nursing knowledge. This study explores the concept of sexual attraction in a Taiwanese social context using concept analysis based on an evolutionary perspective. Inductive inquiry is used to compare and contrast articles from the academic literature, magazines, and newspapers, and data from participant observation and interviews are used to generate exemplars. The process by which the concept of sexual attraction has evolved over time is captured from three distinct aspects: significance, use, and application. The definitional statement of sexual attraction includes the five dimensions of: 1. sexual-oriented psychological dynamics; 2. personal aesthetics and sensory experience; 3. instinct body forces; 4. body language of self; and 5. social and cultural norms. This study scrutinized the changes in attributes that emphasize the biological, objectified body, and stereotyped gender roles of women. Further directions for research and nursing knowledge development are suggested. Examples include identifying the changes in the concept of sexual attraction that result from technological advancement and further clarifying the experiential knowledge of sexual attraction that represents the selfhood and independence of women in Taiwan.

Heterosexual men's ratings of sexual attractiveness of pubescent girls: Effects of labeling the target as under or over the age of sexual consent.

PubMed

O'Donnell, Muireann; Lowe, Rob; Brotherton, Hannah; Davies, Hannah; Panou, Anna; Bennett, Paul

2014-02-01

The study aimed to identify implicit and explicit processes involved in reporting the sexual attractiveness of photographs of the same pubescent girls labeled as either under or within the age of sexual consent in the UK, women, and men. In two studies, 53 and 70 heterosexual men (M age 25.2 and 31.0 years) rated the sexual attractiveness of photographs in each category presented via computer [seeing target photographs of girls labeled as either under- (14-15 years) or within the age of consent (16-17 years)], using a 7-point response box. Ratings in Study 1 were in response to a question asking participants to rate how sexually attractive the person in each photograph was. In Study 2, participants rated how sexually attractive they personally found the target. Response times were also recorded. Several findings were replicated in both studies (although the strength of findings differed). Mean ratings of the sexual attractiveness of the underage girls were lower than those of overage girls and women. In addition, correlations revealed significantly longer responding times when "underage" girls (and men) were rated as more highly sexually attractive. No such relationship emerged with the same girls labeled within the age of consent or women. Overall, these data suggest that men find pubescent girls identified as being under the age of consent sexually attractive, but inhibit their willingness to report this; the greater the attraction, the greater the inhibition.

Functional brain correlates of heterosexual paedophilia.

PubMed

Schiffer, Boris; Paul, Thomas; Gizewski, Elke; Forsting, Michael; Leygraf, Norbert; Schedlowski, Manfred; Kruger, Tillmann H C

2008-05-15

Although the neuronal mechanisms underlying normal sexual motivation and function have recently been examined, the alterations in brain function in deviant sexual behaviours such as paedophilia are largely unknown. The objective of this study was to identify paedophilia-specific functional networks implicated in sexual arousal. Therefore a consecutive sample of eight paedophile forensic inpatients, exclusively attracted to females, and 12 healthy age-matched heterosexual control participants from a comparable socioeconomic stratum participated in a visual sexual stimulation procedure during functional magnetic resonance imaging. The visual stimuli were sexually stimulating photographs and emotionally neutral photographs. Immediately after the imaging session subjective responses pertaining to sexual desire were recorded. Principally, the brain response of heterosexual paedophiles to heteropaedophilic stimuli was comparable to that of heterosexual males to heterosexual stimuli, including different limbic structures (amygdala, cingulate gyrus, and hippocampus), the substantia nigra, caudate nucleus, as well as the anterior cingulate cortex, different thalamic nuclei, and associative cortices. However, responses to visual sexual stimulation were found in the orbitofrontal cortex in healthy heterosexual males, but not in paedophiles, in whom abnormal activity in the dorsolateral prefrontal cortex was observed. Thus, in line with clinical observations and neuropsychological studies, it seems that central processing of sexual stimuli in heterosexual paedophiles may be altered by a disturbance in the prefrontal networks, which, as has already been hypothesized, may be associated with stimulus-controlled behaviours, such as sexual compulsive behaviours. Moreover, these findings may suggest a dysfunction (in the functional and effective connectivity) at the cognitive stage of sexual arousal processing.

Communicating with School Staff about Sexual Identity, Health and Safety: An Exploratory Study of the Experiences and Preferences of Black and Latino Teen Young Men who have Sex with Men

PubMed Central

Lesesne, Catherine A.; Rasberry, Catherine N.; Kroupa, Elizabeth; Topete, Pablo; Carver, Lisa H.; Morris, Elana; Robin, Leah

2015-01-01

Purpose This exploratory study examined the experiences of black and Latino teen young men who have sex with men (YMSM) and their preferences for communication with school staff about matters related to sexual orientation. Methods Participants for this study were recruited in three urban centers in the United States and by multiple community-based organizations serving black and Latino YMSM. Eligible youth were male, black or Latino, ages 13-19, enrolled in 90 days of school in the previous 18 months, and reported attraction to or sexual behavior with other males, or identified as gay or bisexual. Participants completed Web-based questionnaires (n=415) and/or in-depth interviews (n=32). Results Questionnaire participants reported willingness to talk to at least one school staff member about: safety, dating and relationships, and feeling attracted to other guys (63.4%, 58.4%, and 55.9%, respectively). About one-third of the sample reported they would not talk with any school staff about these topics. Exploratory analyses revealed youth who experienced feeling unsafe at school and who had higher levels of trust in the information provided by school staff were more likely to be willing to talk with school staff about safety issues, dating, or same sex attraction (aOR=2.80 and aOR=4.85, respectively). Interview participants reported being most willing to talk to staff who (1) were able and willing to help them; (2) would keep discussions confidential, and (3) expressed genuine care. Preferences for confiding in school staff perceived to be LGBT and having similar racial/ethnic background were also noted. Conclusion Findings suggest school staff can serve as points of contact for reaching YMSM and professional development and interventions can be tailored to reach YMSM and connect them to services they need. Additional research is needed to understand how to increase YMSM comfort talking with school staff about sexual health or sexual identity concerns. PMID:26436114

Communicating with School Staff About Sexual Identity, Health and Safety: An Exploratory Study of the Experiences and Preferences of Black and Latino Teen Young Men Who Have Sex with Men.

PubMed

Lesesne, Catherine A; Rasberry, Catherine N; Kroupa, Elizabeth; Topete, Pablo; Carver, Lisa H; Morris, Elana; Robin, Leah

2015-09-01

This exploratory study examined the experiences of black and Latino teen young men who have sex with men (YMSM) and their preferences for communication with school staff about matters related to sexual orientation. Participants for this study were recruited in three urban centers in the United States and by multiple community-based organizations serving black and Latino YMSM. Eligible youth were male, black and Latino, ages 13–19, enrolled in 90 days of school in the previous 18 months, and reported attraction to or sexual behavior with other males, or identified as gay or bisexual. Participants completed web-based questionnaires (n=415) and/or in-depth interviews (n=32). Questionnaire participants reported willingness to talk to at least one school staff member about: safety, dating and relationships, and feeling attracted to other guys (63.4%, 58.4%, and 55.9%, respectively). About one-third of the sample reported they would not talk with any school staff about these topics. Exploratory analyses revealed youth who experienced feeling unsafe at school and who had higher levels of trust in the information provided by school staff were more likely to be willing to talk with school staff about safety issues, dating, or same sex attraction (adjusted odds ratio [AOR]=2.80 and AOR=4.85, respectively). Interview participants reported being most willing to talk to staff who were able and willing to help them, who would keep discussions confidential, and who expressed genuine care. Preferences for confiding in school staff perceived to be lesbian, gay, bisexual, and transgender (LGBT) and having similar racial/ethnic background were also noted. Findings suggest school staff can serve as points of contact for reaching YMSM and professional development and interventions can be tailored to reach YMSM and connect them to services they need. Additional research is needed to understand how to increase YMSM comfort talking with school staff about sexual health or sexual identity concerns.

Sexual practices, identities and health among women who have sex with women in Lesotho - a mixed-methods study.

PubMed

Poteat, Tonia; Logie, Carmen; Adams, Darrin; Lebona, Judith; Letsie, Puleng; Beyrer, Chris; Baral, Stefan

2014-01-01

Despite the high prevalence of HIV and STIs among women in Africa and the growing literature on HIV and STIs among women who have sex with women, research on the sexual health of women who have sex with women in Africa is scant. This study used mixed methods to describe sexual identity, practices and health among women who have sex with women in Lesotho. Most respondents (48%) described themselves as lesbian, 29% as bisexual and 23% as heterosexual. Almost half (45%) had disclosed their same-sex attraction to family, but only 25% had done so with healthcare workers. A total of 8% reported having HIV. Self-reported HIV was associated with having three or more male partners, having male and female partners at the same time and having a history of STIs. Gender norms, the criminalisation of homosexuality, varied knowledge of, and access to, safer-sex strategies, and mixed experiences of HIV/STI testing and sexual healthcare provided social and structural contexts for HIV- and STI-related vulnerability.

Hot or Not: Response Inhibition Reduces the Hedonic Value and Motivational Incentive of Sexual Stimuli

PubMed Central

Ferrey, Anne E.; Frischen, Alexandra; Fenske, Mark J.

2012-01-01

The motivational incentive of reward-related stimuli can become so salient that it drives behavior at the cost of other needs. Here we show that response inhibition applied during a Go/No-go task not only impacts hedonic evaluations but also reduces the behavioral incentive of motivationally relevant stimuli. We first examined the impact of response inhibition on the hedonic value of sex stimuli associated with strong behavioral-approach responses (Experiment 1). Sexually appealing and non-appealing images were both rated as less attractive when previously encountered as No-go (inhibited) than as Go (non-inhibited) items. We then discovered that inhibition reduces the motivational incentive of sexual appealing stimuli (Experiment 2). Prior Go/No-go status affected the number of key-presses by heterosexual males to view erotic-female (sexually appealing) but not erotic-male or scrambled-control (non-appealing) images. These findings may provide a foundation for developing inhibition-based interventions to reduce the hedonic value and motivational incentive of stimuli associated with disorders of self-control. PMID:23272002

The Male Aesthetic Patient: Facial Anatomy, Concepts of Attractiveness, and Treatment Patterns.

PubMed

Keaney, Terrence C; Anolik, Robert; Braz, André; Eidelman, Michael; Eviatar, Joseph A; Green, Jeremy B; Jones, Derek H; Narurkar, Vic A; Rossi, Anthony M; Gallagher, Conor J

2018-01-01

BACKGROUND: The number of nonsurgical aesthetic procedures performed in men is growing rapidly. However, there are limited data on treatment principles and goals for the male aesthetic patient.

OBJECTIVE: To review the objective data available on male aging and aesthetics and to synthesize with expert opinion on treatment considerations specific to male patients.

METHODS: Expert advisors met to discuss anatomical differences in male versus female facial anatomy related to aging, facial treatment preferences in aesthetically oriented men, and current dosing data for facial injectable treatments in male versus female patients.

RESULTS: Symmetry, averageness, sexual dimorphism, and youthfulness are generally accepted as factors that contribute to the perception of attractiveness. There are differences between men and women in facial anatomy, concepts of attractiveness in the context of masculinity and femininity, and treatment objectives. A communication gap exists for men, as evidenced by the lack of information available online or by word of mouth about injectable treatments.

CONCLUSIONS: Approaches to aesthetic consultation and treatment should differ between men and women based on the fundamental dissimilarities between the sexes. Educating men about available aesthetic treatments and about the safety and side effects associated with each treatment, as well as addressing concerns about their treatment results looking natural, are key considerations.

J Drugs Dermatol. 2018;17(1):19-28.

Sex Attracts: Investigating Individual Differences in Attentional Bias to Sexual Stimuli

PubMed Central

Kagerer, Sabine; Wehrum, Sina; Klucken, Tim; Walter, Bertram; Vaitl, Dieter; Stark, Rudolf

2014-01-01

We investigated the impact of sexual stimuli and the influence of sexual motivation on the performance in a dot-probe task and a line-orientation task in a large sample of males and females. All pictures (neutral, erotic) were rated on the dimensions of valence, arousal, disgust, and sexual arousal. Additionally, questionnaires measuring sexual interest/desire/motivation were employed. The ratings of the sexual stimuli point to a successful picture selection because sexual arousal did not differ between the sexes. The stimuli were equally arousing for men and women. Higher scores in the employed questionnaires measuring sexual interest/desire/motivation led to higher sexual arousal ratings of the sex pictures. Attentional bias towards sex pictures was observed in both experimental tasks. The attentional biases measured by the dot-probe and the line-orientation task were moderately intercorrelated suggesting attentional bias as a possible marker for a sex-attention trait. Finally, only the sexual sensation seeking score correlated with the attentional biases of the two tasks. Future research is needed to increase the predictive power of these indirect measures of sexual interest. PMID:25238545

Do Masculine Men Smell Better? An Association Between Skin Color Masculinity and Female Preferences for Body Odor.

PubMed

Carrito, Mariana L; Santos, Isabel M; Alho, Laura; Ferreira, Jacqueline; Soares, Sandra C; Bem-Haja, Pedro; Silva, Carlos F; Perrett, David I

2017-03-01

A recent study claimed face skin color as a sexually dimorphic variable that influences attractiveness preferences in mate choice. Thereby, skin color may assume the role of a mate quality signal influencing attractiveness preferences. As body odor is linked to attractiveness, this study aimed to explore whether the odors of men with more masculine facial skin color would be evaluated more positively than odors from less masculine men. Female raters were presented with body odors of 18 men and were asked to rate them in various characteristics. Multilevel modeling revealed that the odors of the donors with more masculine color were rated not only as more attractive, more pleasant, and sexier, but also healthier. This indicates that odor associated with men with more masculine skin color is attractive, just as other sexually dimorphic traits. Furthermore, we found a negative relation between skin color masculinity and perceived odor maleness. Regarding this last finding, a new discussion is introduced with respect to the influence of cognitive stereotypes in odor judgments. Altogether, the study supports the possibility that chemosensory signals may be communicating signs of mate quality associated with masculinity. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A global research synthesis of HIV and STI biobehavioral risks in female-to-male (FTM) transgender adults

PubMed Central

Reisner, Sari L.; Murchison, Gabriel R.

2016-01-01

There is a growing interest in HIV infection and sexually transmitted infection (STI) disease burden and risk among transgender people globally; however, the majority of work has been conducted with male-to-female (MTF) transgender populations. This research synthesis comprehensively reviews HIV and STI research in female-to-male (FTM) transgender adults. A paucity of research exists about HIV and STIs in FTMs. Only 25 peer-reviewed papers (18 quantitative, 7 qualitative) and 11 ‘grey literature’ reports were identified, most in the U.S. or Canada, that include data identifying HIV and STI risks in FTMs (five with fully laboratory-confirmed HIV and/or STIs, and five with partial laboratory confirmation). Little is known about the sexual and drug use risk behaviors contributing to HIV and STIs in FTMs. Future directions are suggested, including the need for routine surveillance and monitoring of HIV and STIs globally by transgender identity, more standardized sexual risk assessment measures, targeted data collection in lower and middle income countries, and explicit consideration of the rationale for inclusion/exclusion of FTMs in category-based prevention approaches with MSM and transgender people. Implications for research, policy, programming, and interventions are discussed, including the need to address diverse sexual identities, attractions, and behaviors and engage local FTM communities. PMID:26785800

Self-Perceptions of Sexual Attractiveness: Satisfaction With Physical Appearance is Not of Primary Importance Across Gender and Sexual Orientation.

PubMed

Amos, Natalie; McCabe, Marita P

2016-01-01

Research on self-perceived sexual attractiveness has predominantly focused on the importance of physical appearance, overlooking nonphysical traits that may contribute to these self-perceptions. The present study examined and compared the importance of a variety of traits for self-perceived sexual attractiveness. Self-identified heterosexual, gay, and bisexual men (N = 1,801) and heterosexual, lesbian, and bisexual women (N = 1,092) completed an online questionnaire examining self-perceived sexual attractiveness, body esteem, sexual esteem, adherence to gender norms, and sexual experience. Body esteem and sexual esteem were significant predictors of self-perceived sexual attractiveness, regardless of gender and sexual orientation. Adhering to a masculine gender norm was a significant predictor among all groups (to varying extents) but heterosexual women. Adhering to a feminine gender norm was a significant predictor among heterosexual men and bisexual women. Finally, sexual experience was a significant predictor for all men and bisexual women. Furthermore, while body esteem was a predictor across all groups, for most individuals it did not appear to be of primary importance, with either sexual esteem or masculinity proving to be of greater importance. These findings suggest the need to consider traits related to both physical and nonphysical factors for improving an individual's self-perceived sexual attractiveness.

[The reproductive correlates of social hierarchy in laboratory male mice].

PubMed

Osadchuk, L B; Salomacheva, I N; Bragin, A V; Osadchuk, A V

2007-01-01

In laboratory male mice the effects of social hierarchy on hormonal and spermatogenic testicular function, accessory organs and testicular weights, sexual behaviour have been investigated using an experimental model of social hierarchy, which is characterised by a minimal size (two male mice) and 5 days period of social interactions. The social rank of the partners was detected by asymmetry in aggressive behaviour. Using the experimental condition, when the both partners have no preferences for exclusive use of area we demonstrated that there were no rank differences in the number of mounts and testicular testosterone content. Nevertheless a rank asymmetry in the male sniffing behaviour towards a receptive female, weights of the testes, seminal vesicles, epididymes and the number of epididymal sperm was kept up in a stable social group. Social dominance was found to affect negatively on testicular testosterone increase in response to introduction of a receptive female and sexual attractiveness of male to a receptive female in both dominant and subordinate males. The results obtained demonstrate the impact of social hierarchy on reproduction in laboratory male mice, particular in respect of spermatogenesis and the testicular testosterone in response to a receptive female.

Male preference for female pubic hair: an evolutionary view.

PubMed

Prokop, Pavol

The ectoparasite avoidance hypothesis proposes that human hairlessness was favoured by sexual selection, because hairless individuals suffered from lower parasite loads. Females have seemingly less hairy bodies than men suggesting that the selection toward hairlessness is more intense in females than in males. This study examined male preference for hairy and shaved female genitalia. Pubic hair, although still functional in terms of dissipation of phermononal secretions, was perceived by heterosexual males recruited in the university (age range: 19-38 years, N = 96) as much less attractive as shaved female genitalia. Males who were more disgust sensitive and those who were sexually unrestricted showed a stronger preference for shaved genitalia than others. Self-reported frequency of pornography consumption was associated, contrary to expectations, with a stronger preference for hairy genitalia which suggests that this may be a result of negative frequency dependent selection. Older males also preferred hairy genitalia more than younger males. Overall, these results suggest that a preference for shaved genitalia may be explained by the superficial resemblance of pubic hair with chest hair, which is less developed as in our evolutionary past, perhaps due to the benefits associated with ectoparasite avoidance.

Sex-Specificity in the Reward Value of Facial Attractiveness.

PubMed

Hahn, Amanda C; Fisher, Claire I; DeBruine, Lisa M; Jones, Benedict C

2016-05-01

Studies of the sex-specificity of sexual arousal in adults (i.e., the tendency to respond more strongly to preferred-sex individuals than non-preferred sex individuals) have suggested that heterosexual men, homosexual men, and homosexual women show stronger sex-specific responses than do heterosexual women. Evidence for a similar pattern of results in studies investigating the reward value of faces is equivocal. Consequently, we investigated the effects of (1) sexual orientation (homosexual vs. heterosexual), (2) sex (male vs. female), (3) image sex (preferred-sex vs. non-preferred-sex), and (4) the physical attractiveness of the individual shown in the image on the reward value of faces. Participants were 130 heterosexual men, 130 homosexual men, 130 heterosexual women, and 130 homosexual women. The reward value of faces was assessed using a standard key-press task. Multilevel modeling of responses indicated that images of preferred-sex individuals were more rewarding than images of non-preferred-sex individuals and that this preferred-sex bias was particularly pronounced when more physically attractive faces were presented. These effects were not qualified by interactions involving either the sexual orientation or the sex of our participants, however, suggesting that the preferred-sex bias in the reward value of faces is similar in heterosexual men, homosexual men, heterosexual women, and homosexual women.

Behavioural evidence of male volatile pheromones in the sex-role reversed wolf spiders Allocosa brasiliensis and Allocosa alticeps

NASA Astrophysics Data System (ADS)

Aisenberg, Anita; Baruffaldi, Luciana; González, Macarena

2010-01-01

The use of chemical signals in a sexual context is widespread in the animal kingdom. Most studies in spiders report the use of female pheromones that attract potential sexual partners. Allocosa brasiliensis and Allocosa alticeps are two burrowing wolf spiders that show sex-role reversal. Females locate male burrows and initiate courtship before males perform any detectable visual or vibratory signal. So, females of these species would be detecting chemical or mechanical cues left by males. Our objective was to explore the potential for male pheromones to play a role in mate detection in A. brasiliensis and A. alticeps. We designed two experiments. In Experiment 1, we tested the occurrence of male contact pheromones by evaluating female courtship when exposed to empty burrows constructed by males or females (control). In Experiment 2, we tested the existence of male volatile pheromones by evaluating female behaviour when exposed to artificial burrows connected to tubes containing males, females or empty tubes (control). Our results suggest the occurrence of male volatile pheromones that trigger female courtship in both Allocosa species. The sex-role reversal postulated for these wolf spiders could be driving the consequent reversal in typical pheromone-emitter and detector roles expected for spiders.

Self-perceived attractiveness, romantic desirability and self-esteem: a mating sociometer perspective.

PubMed

Bale, Christopher; Archer, John

2013-01-26

Sociometer theory proposes that self-esteem is an adaptation which evolved to monitor and regulate interpersonal relationships. It is therefore sensitive to self-assessments in domains relevant to relational desirability. Positive relationships between self-perceived physical attractiveness and self-esteem found in previous studies may reflect the functioning of a mating sociometer, designed to monitor individuals' desirability as romantic or sexual partners. We thus predicted that these relationships should be mediated by self-perceptions of romantic desirability, or more specifically, individuals' confidence in their abilities to successfully establish and maintain romantic relationships. Two hundred and eighty seven young adults (98 male) completed an online measure of self-perceived attractiveness, together with measures of self-confidence in appearance and romantic relationships, body-esteem and global self-esteem. Linear regression analyses indicated that self-perceived attractiveness, self-confidence in appearance and body-esteem all significantly predicted self-esteem, and that in each case, the relationship was mediated by romantic self-confidence. Self-perceived attractiveness predicted self-esteem significantly more strongly in females than in males. We discuss these results in relation to sociometer and parental investment theories, and explore limitations and future directions.

Romantic red: red enhances men's attraction to women.

PubMed

Elliot, Andrew J; Niesta, Daniela

2008-11-01

In many nonhuman primates, the color red enhances males' attraction to females. In 5 experiments, the authors demonstrate a parallel effect in humans: Red, relative to other achromatic and chromatic colors, leads men to view women as more attractive and more sexually desirable. Men seem unaware of this red effect, and red does not influence women's perceptions of the attractiveness of other women, nor men's perceptions of women's overall likeability, kindness, or intelligence. The findings have clear practical implications for men and women in the mating game and, perhaps, for fashion consultants, product designers, and marketers. Furthermore, the findings document the value of extending research on signal coloration to humans and of considering color as something of a common language, both within and across species. (c) 2008 APA, all rights reserved.

Effect of acclimation to outdoor condition on the sexual performance of mass-produced Medflies (Diptera: Tephritidae)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pereira, R.; Silva, N.; Quintal, C.

Application of the sterile insect technique (SIT) as part of integrated area-wide programs to control the Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) require that the released males attract wild females and transfer sterile sperm. However, knowledge about male sexual performance after they are released is scarce. We conducted a study to evaluate male sexual performance in field cage tests, according to standard quality control procedures. Mass-reared 5-d-old sterile males from the genetic sexing strain VIENNA 7mix2000 were acclimated for 0, 1, and 3 d to outdoor conditions before competing with wild males for wild females. Although the proportion ofmore » mating (PM) in the test was satisfactory, the resulting relative sterility index (RSI) data showed no significant differences among the treatments. The data indicate that pre-conditioning males to outdoor conditions in Madeira did not confer an advantage in field cage sexual performance. (author) [Spanish] La aplicacion de la tecnica del insecto esteril (TIE) como parte de un programa integrado de amplio efecto para el control de la mosca mediterranea de la fruta Ceratitis capitata (Wiedemann) requiere que los machos liberados atraigan las hembras naturales y transfieran su esperma. Sin embargo, el conocimiento del desempeno sexual de los machos despues de ser liberados es muy escaso. Nosotros realizamos un estudio para evaluar el desempeno sexual de los machos en pruebas usando jaulas del campo, segun los procedimientos estandardizados de calidad. Machos esteriles de 5 dias de edad de la raza que separa los sexos geneticamente VIENNA 7mix2000 criados en masa fueron aclimatados por 0, 1 y 3 dias en condiciones de campo antes de competir con machos naturales para las hembras naturales. Aunque la proporcion del apareamiento en la prueba fue satisfactorio, el indice relativo de esterilidad (IRS) resultante no mostro ninguna diferencia significativa entre los tratamientos. Los datos indicaron que al condicionar los machos anteriormente a las condiciones de campo en Madeira no conferio ventaja alguna en el desempeno sexual en la jaula de campo. (author)« less

Congruence across Sexual Orientation Dimensions and Risk for Unintended Pregnancy among Adult U.S. Women.

PubMed

Hartnett, Caroline Sten; Lindley, Lisa L; Walsemann, Katrina M

To date, no studies have investigated whether sexual minority women (SMW) are more likely to experience unintended pregnancies compared with their heterosexual peers. The aim of this study was to explore whether adult SMW were more likely to have unintended pregnancies compared with heterosexual women, to examine the role of identity-attraction congruence in unintended pregnancy risk, and to evaluate possible mediators. Data on pregnancies to women ages 18 to 44 were drawn from the 2006 through 2013 National Survey of Family Growth (n = 25,403). Weighted logistic regression models estimated the likelihood of reporting an unintended (rather than intended) pregnancy by identity-attraction congruence and the extent to which this association was mediated by sexual experiences with men, including age at first sex and number of sexual partners. Supplementary analyses addressed the issue of abortion underreporting. Pregnancies to SMW were more likely to be unintended compared with pregnancies to heterosexual women (adjusted odds ratio, 1.26; 95% confidence interval, 1.08-1.46). This was driven by the elevated risk experienced by heterosexual-identified women with same-sex attractions, specifically (adjusted odds ratio, 1.28; 95% confidence interval, 1.08-1.51). Greater unintended pregnancy risk among these women was mediated by a greater number of male sex partners compared with heterosexual women. Unintended pregnancy risk among SMW has historically received little attention from scholars and clinicians. Future research should explore the specific conditions that put heterosexual-identified women with same sex attractions at increased risk for unintended pregnancy. Clinicians should consider these dynamics when screening patients for contraceptive counseling. Copyright © 2016 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

Men sexually interested in transwomen (MSTW): gendered embodiment and the construction of sexual desire.

PubMed

Weinberg, Martin S; Williams, Colin J

2010-07-01

This article extends research on transgenderism by providing a sociological study of men who are sexually interested in transwomen (MSTW; viz., genetic males who use estrogen to feminize their body but retain their penis). We conducted fieldwork in a bar catering to transwomen and the men who were sexually interested in them, and did on-the-spot interviews with the MSTW. We initially examined the nature of MSTW's sexual attraction to transwomen, followed by how this related to their sexual orientation identity. Using a sexual fields approach (Green, 2008), we first found how the ambience of the bar helped to create an erotic environment through a heightened sense of gender. Then, focusing on the theory of embodiment (Jackson & Scott, 2007), we saw how the MSTW constructed a unique sexual desire according to the sexual orientation identity they brought to the situation. Those who identified as "straight" tended to gloss that the transwoman had a penis, while the bisexually identified men were more likely to incorporate the transwoman's penis into the sexual experience.

Treatment regimen, sexual attractiveness concerns and psychological adjustment among African American breast cancer patients.

PubMed

Taylor, Kathryn L; Lamdan, Ruth M; Siegel, Jamie E; Shelby, Rebecca; Hrywna, Mary; Moran-Klimi, Karen

2002-01-01

Among a sample of African American women recently diagnosed with breast cancer, we assessed the consequences of different treatment regimens on sexual attractiveness concerns, and the impact of sexual attractiveness concerns on current and subsequent psychological adjustment. The sample included 91 African American women with breast cancer; 90% had Stage I or II disease, 48% had chemotherapy, 47% had a lumpectomy, and 53% received a mastectomy. Feelings of sexual attractiveness and psychological adjustment were assessed an average of 3 months following surgery and again 4 months post-baseline. Regression analyses revealed that chemotherapy was associated with greater concerns about sexual attractiveness among lumpectomy patients (p<0.05), but not among mastectomy patients (p>0.20). The interaction also suggested that chemotherapy equalized the impact of types of surgery, as there was no difference on sexual attractiveness between surgery groups among women who had received chemotherapy (p>0.20). However, among women who had not received chemotherapy, mastectomy patients reported greater sexual attractiveness concerns (p<0.01). Finally, regression analyses revealed that feelings of sexual attractiveness were an important component of psychological well-being, both cross-sectionally (p<0.001) and longitudinally (p<0.001). Assessment of the combined impact of different treatment regimens on feelings of sexual attractiveness is particularly important given the current consensus that all breast cancer patients should receive chemotherapy, regardless of nodal status. Further, concerns about sexual attractiveness should be considered for inclusion as one component of psychosocial support programs for African American women with breast cancer, as our results suggested that they played a significant role in psychological adjustment. Copyright 2002 John Wiley & Sons, Ltd.

Male-male competition and female choice are differentially affected by male call acoustics in the serrate-legged small treefrog, Kurixalus odontotarsus.

PubMed

Zhu, Bicheng; Wang, Jichao; Zhao, Longhui; Chen, Qinghua; Sun, Zhixin; Yang, Yue; Brauth, Steven E; Tang, Yezhong; Cui, Jianguo

2017-01-01

The evolution of exaggerated vocal signals in anuran species is an important topic. Males and females have both evolved the ability to discriminate communication sounds. However, the nature of sexual dimorphism in cognition and sensory discrimination and in the evolution and limitation of sexual signal exaggeration remain relatively unexplored. In the present study, we used male calls of varied complexity in the serrate-legged small treefrog, Kurixalus odontotarsus , as probes to investigate how both sexes respond to variations in call complexity and how sex differences in signal discrimination play a role in the evolution of sexual signal exaggeration. The compound calls of male K. odontotarsus consist of a series of one or more harmonic notes (A notes) which may be followed by one or more short broadband notes (B notes). Male playback experiments and female phonotaxis tests showed that increasing the number of A notes in stimulus calls elicits increased numbers of response calls by males and increases the attractiveness of the stimulus calls to females. The addition of B notes, however, reduces male calling responses. Moreover, call stimuli which contain only B notes suppress spontaneous male calling responses. Phonotaxis experiments show that females prefer calls with greater numbers of A notes and calls containing both A notes and B notes, but do not prefer calls with only B notes. Male-male competition and female choice appear to have played different roles in the evolution and limitation of signal complexity in K. odontotarsus . These results provide new insights into how exaggerated compound signals evolve and how signal complexity may be limited in anurans.

The role of motivation and reward neural systems in vocal communication in songbirds

PubMed Central

Riters, Lauren V.

2012-01-01

Many vertebrates are highly motivated to communicate, suggesting that the consequences of communication may be rewarding. Past studies show that dopamine and opioids in the medial preoptic nucleus (mPOA) and ventral tegmental area (VTA) play distinct roles in motivation and reward. In songbirds, multiple lines of recent evidence indicate that the roles of dopamine and opioid activity in mPOA and VTA in male birdsong differ depending upon whether song is used to attract females (sexually-motivated) or is produced spontaneously (undirected). Evidence is reviewed supporting the hypotheses that 1) mPOA and VTA interact to influence the context in which a male sings, 2) distinct patterns of dopamine activity underlie the motivation to produce sexually-motivated and undirected song, 3) sexually-motivated communication is externally reinforced by opioids released as part of social interactions, and 4) undirected communication is facilitated and rewarded by immediate opioid release linked to the act of singing. PMID:22569510

The role of motivation and reward neural systems in vocal communication in songbirds.

PubMed

Riters, Lauren V

2012-04-01

Many vertebrates are highly motivated to communicate, suggesting that the consequences of communication may be rewarding. Past studies show that dopamine and opioids in the medial preoptic nucleus (mPOA) and ventral tegmental area (VTA) play distinct roles in motivation and reward. In songbirds, multiple lines of recent evidence indicate that the roles of dopamine and opioid activity in mPOA and VTA in male birdsong differ depending upon whether song is used to attract females (sexually-motivated) or is produced spontaneously (undirected). Evidence is reviewed supporting the hypotheses that (1) mPOA and VTA interact to influence the context in which a male sings, (2) distinct patterns of dopamine activity underlie the motivation to produce sexually-motivated and undirected song, (3) sexually-motivated communication is externally reinforced by opioids released as part of social interactions, and (4) undirected communication is facilitated and rewarded by immediate opioid release linked to the act of singing. Copyright © 2012 Elsevier Inc. All rights reserved.

Your Face is Your Fortune: Does Adolescent Attractiveness Predict Intimate Relationships Later in Life?

PubMed

Karraker, Amelia; Sicinski, Kamil; Moynihan, Donald

2017-01-01

A growing literature documents the importance of physical attractiveness in young and middle adulthood for romantic, marital, and sexual relationships, but little is known about how attractiveness in adolescence matters to intimate relationships in later life. We ask: does attractiveness early in life convey ongoing benefits late in life, or do such benefits erode over time? We use multivariate regression models and more than 50 years of data from the Wisconsin Longitudinal Study to examine the connections between adolescent physical attractiveness and intimate relationships (i.e., sexual activity and access to potential sexual partners) in later life. We find that adolescent attractiveness facilitates sexual activity in later life. This relationship is largely driven by attractiveness increasing the probability of having access to potential sexual partners. However, attractiveness is not related to sexual activity among married couples, even after controlling for marital duration. Men, those in good health, and wealthier individuals are also more likely to engage in several facets of intimate relationships. These findings highlight the importance of relationship context for later life sexual activity and begin to explicate the pathways through which factors across the life course-particularly attractiveness-influence sexual activity in later life. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Your Face is Your Fortune: Does Adolescent Attractiveness Predict Intimate Relationships Later in Life?

PubMed Central

Sicinski, Kamil; Moynihan, Donald

2017-01-01

Objective: A growing literature documents the importance of physical attractiveness in young and middle adulthood for romantic, marital, and sexual relationships, but little is known about how attractiveness in adolescence matters to intimate relationships in later life. We ask: does attractiveness early in life convey ongoing benefits late in life, or do such benefits erode over time? Methods: We use multivariate regression models and more than 50 years of data from the Wisconsin Longitudinal Study to examine the connections between adolescent physical attractiveness and intimate relationships (i.e., sexual activity and access to potential sexual partners) in later life. Results: We find that adolescent attractiveness facilitates sexual activity in later life. This relationship is largely driven by attractiveness increasing the probability of having access to potential sexual partners. However, attractiveness is not related to sexual activity among married couples, even after controlling for marital duration. Men, those in good health, and wealthier individuals are also more likely to engage in several facets of intimate relationships. Discussion: These findings highlight the importance of relationship context for later life sexual activity and begin to explicate the pathways through which factors across the life course—particularly attractiveness—influence sexual activity in later life. PMID:26655646

A contact anti-aphrodisiac pheromone supplied by the spermatophore in the rove beetle Aleochara curtula: mode of transfer and evolutionary significance

NASA Astrophysics Data System (ADS)

Schlechter-Helas, Jerry; Schmitt, Thomas; Peschke, Klaus

2011-10-01

By reducing the attractiveness of their mating partner via an anti-aphrodisiac pheromone, males can prevent a remating of the female and thus reduce the risk of sperm competition. For females, the main benefit from allowing the chemical manipulation of their attractiveness is probably the avoidance of sexual harassments from rival males. While mating plugs generally constitute a physical barrier which hinders male mating attempts, chemical manipulations must trustfully inform the responding male of the female's reluctance to mate; otherwise, it would be beneficial to ignore the repellent information. In our experiments, males of the polyandrous rove beetle Aleochara curtula chemically manipulated the attractiveness of their mating partner. Coincident with the deposition of a spermatophore into the female genital chamber, an anti-aphrodisiac pheromone was transferred and readily spread onto the female surface, where it was subsequently perceived by rival males via parameres, the claspers of the male genitalia. Males aborted contact with the mated female to avoid further time- and energy-consuming elements of the mating sequence. The chemical mode of action was demonstrated inter alia by spicing virgin females with spermatophore extracts. The action of the anti-aphrodisiac correlated with the persistence of the spermatophore in the female genital chamber and corresponded to the length of stay of the mated female at a carcass, where the density of rival males is highest. The ensuing benefits for all three parties involved in this communication system, which render this post-copulatory mate guarding strategy evolutionary stable, are discussed.

Embryonic origin of mate choice in a lizard with temperature-dependent sex determination.

PubMed

Putz, Oliver; Crews, David

2006-01-01

Individual differences in the adult sexual behavior of vertebrates are rooted in the fetal environment. In the leopard gecko (Eublepharis macularius), a species with temperature-dependent sex determination (TSD), hatchling sex ratios differ between incubation temperatures, as does sexuality in same-sex animals. This variation can primarily be ascribed to the temperature having direct organizing actions on the brain. Here we demonstrate that embryonic temperature can affect adult mate choice in the leopard gecko. Given the simultaneous choice between two females from different incubation temperatures (30.0 and 34.0 degrees C), males from one incubation temperature (30.0 degrees C) preferred the female from 34.0 degrees C, while males from another incubation temperature (32.5 degrees C) preferred the female from 30.0 degrees C. We suggest that this difference in mate choice is due to an environmental influence on brain development leading to differential perception of opposite-sex individuals. This previously unrecognized modulator of adult mate choice lends further support to the view that mate choice is best understood in the context of an individual's entire life-history. Thus, sexual selection results from a combination of the female's as well as the male's life history. Female attractiveness and male choice therefore are complementary. Copyright 2005 Wiley Periodicals, Inc.

Experiment of nurture: ablatio penis at 2 months, sex reassignment at 7 months, and a psychosexual follow-up in young adulthood.

PubMed

Bradley, S J; Oliver, G D; Chernick, A B; Zucker, K J

1998-07-01

Guidelines of psychosexual management for infants born with physical intersex conditions are intended to assist physicians and parents in making decisions about sex of assignment and rearing including the following: 1) sex assignment should be to the gender that carries the best prognosis for good reproductive function, good sexual function, normal-looking external genitalia and physical appearance, and a stable gender identity; 2) the decision regarding sex assignment should be made as early as possible, preferably during the newborn period, with an upper age limit for reversal of an initial sex assignment no later than 18 to 24 months; and 3) there should be minimal uncertainty and ambiguity on the part of parents and professionals regarding the final decision about sex assignment and rearing. J. Money used these guidelines in a case of a biologically normal male infant (one of a pair of monozygotic twins) whose penis was accidentally ablated during a circumcision at the age of 7 months. The decision to reassign the infant boy to the female sex and to rear him as a girl was made at 17 months, with surgical castration and initial genital reconstruction occurring at 21 months. Money reported follow-up data on this child through the age of 9 years. Although the girl was described as having many "tomboyish" behavioral traits, a female gender identity had apparently differentiated. Thus, it was concluded that gender identity is sufficiently incompletely differentiated at birth as to permit successful assignment of a genetic male as a girl, in keeping with the experiences of rearing. Subsequent follow-up by other investigators reported that by early adolescence the patient had rejected the female identity and began to live as a male at the age of 14 years. In adulthood, the patient recalled that he had never felt comfortable as a girl, and his mother reported similar recollections. At age 25, the patient married a woman and adopted her children. The patient reported exclusive sexual attraction to females. The present case report is a long-term psychosexual follow-up on a second case of ablatio penis in a 46 XY male. During an electrocautery circumcision at the age of 2 months, the patient sustained a burn of the skin of the entire penile shaft, and the penis eventually sloughed off. At age 7 months, the remainder of the penis and the testes were removed. By age 7 months, if not earlier, the decision was made to reassign the patient as a female and to raise the infant as a girl. The patient was interviewed on two occasions: at 16 years and twice while in the hospital for additional surgery at 26 years of age. At ages 16 and 26, the patient was living socially as a woman and denied any uncertainty about being a female. During childhood, the patient recalled that she self-identified as a "tomboy" and enjoyed stereotypically masculine toys and games; however, the patient also recalled that her favorite playmates were usually girls and that her best friend was always a girl. When seen at age 16, the patient had been admitted to the hospital for vaginoplasty. At that time, she wished to proceed with the further repair of her genitalia to make them suitable for sexual intercourse with males. At age 26, the patient returned to the hospital for further vaginoplasty. Regarding the patient's sexual orientation, she was attracted predominantly to women in fantasy, but had had sexual experiences with both women and men. At the time of the second surgery, she was in a relationship with a man and wished to be able to have intercourse. The patient's self-described sexual identity was "bisexual." After surgery at age 26 years, the patient developed a rectovaginal fistula. Within a few months of the surgery, the patient and her male partner separated for reasons other than the patient's physical problems. The patient subsequently began living with a new partner, a woman, in a lesbian relationship. The psychosexual development of our patient was bot the other patient was married to a woman. Our patient had a "bisexual" sexual identity; the other patient had a "heterosexual" sexual identity. The patients were similar in that they had a childhood history of "tomboyism." Our patient was predominantly sexually attracted to women; the other patient was exclusively sexually attracted to women. Our patient had sexual experiences with both women and men; the other patient had sexual experiences only with women. The most plausible explanation of our patient's differentiation of a female gender identity is that sex of rearing as a female, beginning at around age 7 months, overrode any putative influences of a normal prenatal masculine sexual biology. Because cases of ablatio penis in infancy are so rare and long-term follow-up data are scant, it is obviously impossible to know whether our patient or the previous case would be more typical of the psychosexual outcome in a larger sample of such individuals. However, our case suggests that it is possible for a female gender identity to differentiate in a biologically "normal" genetic male. At present, however, the clinical literature is deeply divided on the best way to manage cases of traumatic loss of the penis during infancy. Further study is clearly required to decide on the optimal model of psychosocial and psychosexual management for affected individuals.

Sex differences in visual attention to sexually explicit videos: a preliminary study.

PubMed

Tsujimura, Akira; Miyagawa, Yasushi; Takada, Shingo; Matsuoka, Yasuhiro; Takao, Tetsuya; Hirai, Toshiaki; Matsushita, Masateru; Nonomura, Norio; Okuyama, Akihiko

2009-04-01

Although men appear to be more interested in sexual stimuli than women, this difference is not completely understood. Eye-tracking technology has been used to investigate visual attention to still sexual images; however, it has not been applied to moving sexual images. To investigate whether sex difference exists in visual attention to sexual videos. Eleven male and 11 female healthy volunteers were studied by our new methodology. The subjects viewed two sexual videos (one depicting sexual intercourse and one not) in which several regions were designated for eye-gaze analysis in each frame. Visual attention was measured across each designated region according to gaze duration. Sex differences, the region attracting the most attention, and visually favored sex were evaluated. In the nonintercourse clip, gaze time for the face and body of the actress was significantly shorter among women than among men. Gaze time for the face and body of the actor and nonhuman regions was significantly longer for women than men. The region attracting the most attention was the face of the actress for both men and women. Men viewed the opposite sex for a significantly longer period than did women, and women viewed their own sex for a significantly longer period than did men. However, gaze times for the clip showing intercourse were not significantly different between sexes. A sex difference existed in visual attention to a sexual video without heterosexual intercourse; men viewed the opposite sex for longer periods than did women, and women viewed the same sex for longer periods than did men. There was no statistically significant sex difference in viewing patterns in a sexual video showing heterosexual intercourse, and we speculate that men and women may have similar visual attention patterns if the sexual stimuli are sufficiently explicit.

Putative Androgen Exposure and Sexual Orientation: Cross-Cultural Evidence Suggesting a Modified Neurohormonal Theory.

PubMed

Ellis, Lee; Lykins, Amy; Hoskin, Anthony; Ratnasingam, Malini

2015-12-01

According to neurohormonal theory, prenatal androgens are key determinants of sexual orientation. As a reputed marker for prenatal androgens, the 2D:4D finger length ratio has been used in more than a dozen studies to test the hypothesis that prenatal androgens influence sexual orientation. Findings have been very inconsistent. The present study sought to retest the hypothesis that 2D:4D and sexual orientation are related is a manner consistent with neurohormonal theory. A 2D:4D measure (of the right hand) along with four additional somatic markers of androgen exposure (height, physical strength, muscularity, and athletic ability) with samples of college students in Malaysia (N = 2,058) and the United States (N = 2,511). The five androgen measures were factor analyzed, resulting in a two-factor solution: Factor 1 consisted of strength, muscularity, and athletic ability (the muscular coordination factor), and Factor 2 was comprised of the r2D:4D and adult height (the bone growth factor). Sexual orientation was measured by asking each respondent the extent to which they were sexually attracted to males and the extent to which they were sexually attracted to females, both on 11-point scales. When the countries and sexes were analyzed separately, neither the r2D:4D measure nor Factor 2 correlated with sexual orientation to significant degrees. Instead, it was the muscular coordination factor that correlated the best. Support was found for the hypothesis that prenatal androgens influence sexual orientation, but the nature of these influences was more complex than neurohormonal theory predicted. A modified theory is needed and presented to accommodate the results from this study. © 2015 International Society for Sexual Medicine.

Hormonal substrate of estrous odor preference in beagles.

PubMed

Anisko, J J

1977-01-01

The effect of testosterone propionate (TP), injected during pregnancy and/or implanted on Days 1-3 of postpartum, on a behavioral preference for estrous vaginal secretions was assessed in beagles. Males castrated in adulthood and intact, untreated males were used to test the attractability of vaginal secretions. Intact and castrated males showed a marked preference for estrous vaginal secretions. Castrated males showed a greater preference for estrous secretions following treatment with TP. Further, females treated with TP before and/or after birth also showed a marked preference for estrous vaginal secretions. The results suggest that the preference for estrous odor is a sexually dimorphic pattern which depends upon developmental and concurrent androgenic stimulation for its manifestation.

Estrogens Can Disrupt Amphibian Mating Behavior

PubMed Central

Hoffmann, Frauke; Kloas, Werner

2012-01-01

The main component of classical contraceptives, 17α-ethinylestradiol (EE2), has high estrogenic activity even at environmentally relevant concentrations. Although estrogenic endocrine disrupting compounds are assumed to contribute to the worldwide decline of amphibian populations by adverse effects on sexual differentiation, evidence for EE2 affecting amphibian mating behaviour is lacking. In this study, we demonstrate that EE2 exposure at five different concentrations (0.296 ng/L, 2.96 ng/L, 29.64 ng/L, 2.96 µg/L and 296.4 µg/L) can disrupt the mating behavior of adult male Xenopus laevis. EE2 exposure at all concentrations lowered male sexual arousal, indicated by decreased proportions of advertisement calls and increased proportions of the call type rasping, which characterizes a sexually unaroused state of a male. Additionally, EE2 at all tested concentrations affected temporal and spectral parameters of the advertisement calls, respectively. The classical and highly sensitive biomarker vitellogenin, on the other hand, was only induced at concentrations equal or higher than 2.96 µg/L. If kept under control conditions after a 96 h EE2 exposure (2.96 µg/L), alterations of male advertisement calls vanish gradually within 6 weeks and result in a lower sexual attractiveness of EE2 exposed males toward females as demonstrated by female choice experiments. These findings indicate that exposure to environmentally relevant EE2 concentrations can directly disrupt male mate calling behavior of X. laevis and can indirectly affect the mating behavior of females. The results suggest the possibility that EE2 exposure could reduce the reproductive success of EE2 exposed animals and these effects might contribute to the global problem of amphibian decline. PMID:22355410

Dimensions of Sexual Orientation and the Prevalence of Mood and Anxiety Disorders in the United States

PubMed Central

Boyd, Carol J.; Hughes, Tonda L.; McCabe, Sean Esteban

2010-01-01

Objectives. We used data from a nationally representative sample to examine the associations among 3 dimensions of sexual orientation (identity, attraction, and behavior), lifetime and past-year mood and anxiety disorders, and sex. Methods. We analyzed data from wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions. Results. Mental health outcomes differed by sex, dimension of sexual orientation, and sexual minority group. Whereas a lesbian, gay, or bisexual identity was associated with higher odds of any mood or anxiety disorder for both men and women, women reporting only same-sex sexual partners in their lifetime had the lowest rates of most disorders. Higher odds of any lifetime mood or anxiety disorder were more consistent and pronounced among sexual minority men than among sexual minority women. Finally, bisexual behavior conferred the highest odds of any mood or anxiety disorder for both males and females. Conclusions. Findings point to mental health disparities among some, but not all, sexual minority groups and emphasize the importance of including multiple measures of sexual orientation in population-based health studies. PMID:19696380

Cognitive ability is heritable and predicts the success of an alternative mating tactic

PubMed Central

Smith, Carl; Philips, André; Reichard, Martin

2015-01-01

The ability to attract mates, acquire resources for reproduction, and successfully outcompete rivals for fertilizations may make demands on cognitive traits—the mechanisms by which an animal acquires, processes, stores and acts upon information from its environment. Consequently, cognitive traits potentially undergo sexual selection in some mating systems. We investigated the role of cognitive traits on the reproductive performance of male rose bitterling (Rhodeus ocellatus), a freshwater fish with a complex mating system and alternative mating tactics. We quantified the learning accuracy of males and females in a spatial learning task and scored them for learning accuracy. Males were subsequently allowed to play the roles of a guarder and a sneaker in competitive mating trials, with reproductive success measured using paternity analysis. We detected a significant interaction between male mating role and learning accuracy on reproductive success, with the best-performing males in maze trials showing greater reproductive success in a sneaker role than as a guarder. Using a cross-classified breeding design, learning accuracy was demonstrated to be heritable, with significant additive maternal and paternal effects. Our results imply that male cognitive traits may undergo intra-sexual selection. PMID:26041347

Cognitive ability is heritable and predicts the success of an alternative mating tactic.

PubMed

Smith, Carl; Philips, André; Reichard, Martin

2015-06-22

The ability to attract mates, acquire resources for reproduction, and successfully outcompete rivals for fertilizations may make demands on cognitive traits--the mechanisms by which an animal acquires, processes, stores and acts upon information from its environment. Consequently, cognitive traits potentially undergo sexual selection in some mating systems. We investigated the role of cognitive traits on the reproductive performance of male rose bitterling (Rhodeus ocellatus), a freshwater fish with a complex mating system and alternative mating tactics. We quantified the learning accuracy of males and females in a spatial learning task and scored them for learning accuracy. Males were subsequently allowed to play the roles of a guarder and a sneaker in competitive mating trials, with reproductive success measured using paternity analysis. We detected a significant interaction between male mating role and learning accuracy on reproductive success, with the best-performing males in maze trials showing greater reproductive success in a sneaker role than as a guarder. Using a cross-classified breeding design, learning accuracy was demonstrated to be heritable, with significant additive maternal and paternal effects. Our results imply that male cognitive traits may undergo intra-sexual selection. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Differences in Sexual Orientation Diversity and Sexual Fluidity in Attractions Among Gender Minority Adults in Massachusetts.

PubMed

Katz-Wise, Sabra L; Reisner, Sari L; Hughto, Jaclyn White; Keo-Meier, Colton L

2016-01-01

This study characterized sexual orientation identities and sexual fluidity in attractions in a community-based sample of self-identified transgender and gender-nonconforming adults in Massachusetts. Participants were recruited in 2013 using bimodel methods (online and in person) to complete a one-time, Web-based quantitative survey that included questions about sexual orientation identity and sexual fluidity. Multivariable logistic regression models estimated adjusted risk ratios (aRRs) and 95% confidence intervals (95% CIs) to examine the correlates of self-reported changes in attractions ever in lifetime among the whole sample (n = 452) and after transition among those who reported social gender transition (n = 205). The sample endorsed diverse sexual orientation identities: 42.7% queer, 19.0% other nonbinary, 15.7% bisexual, 12.2% straight, and 10.4% gay/lesbian. Overall, 58.2% reported having experienced changes in sexual attractions in their lifetime. In adjusted models, trans masculine individuals were more likely than trans feminine individuals to report sexual fluidity in their lifetime (aRR = 1.69; 95% CI = 1.34, 2.12). Among those who transitioned, 64.6% reported a change in attractions posttransition, and trans masculine individuals were less likely than trans feminine individuals to report sexual fluidity (aRR = 0.44; 95% CI = 0.28, 0.69). Heterogeneity of sexual orientation identities and sexual fluidity in attractions are the norm rather than the exception among gender minority people.

A private ultraviolet channel in visual communication.

PubMed Central

Cummings, Molly E; Rosenthal, Gil G; Ryan, Michael J

2003-01-01

Although private communication is considered an important diversifying force in evolution, there is little direct behavioural evidence to support this notion. Here, we show that ultraviolet (UV) signalling in northern swordtails (Xiphophorus) affords a channel for communication that is not accessible to their major predator, Astyanax mexicanus, the Mexican tetra. Laboratory and field behavioural experiments with swordtails (X. nigrensis) and predators (A. mexicanus) demonstrate that male UV ornamentation significantly increases their attractiveness to females but not to this predator, which is less sensitive to UV. UV reflectance among swordtail species correlates positively with tetra densities across habitats, and visual contrast estimates suggest that UV signals are highly conspicuous to swordtails in their natural environment. Cross-species comparisons also support the hypothesis that natural selection drives the use of UV communication. We compared two species, one with high (X. nigrensis) and one with low (X. malinche) Mexican tetra densities. Xiphophorus nigrensis males reflect significantly more UV than X. malinche, exhibit significant UV sexual dimorphism, and UV is a salient component of the sexual communication system. In X. malinche, however, males reflect minimally in the UV, there is no UV sexual dimorphism, and UV does not play a part in its communication system. PMID:12803903

Rhythmic displays of female gibbons offer insight into the origin of dance

PubMed Central

Fan, Peng-Fei; Ma, Chang-Yong; Garber, Paul A.; Zhang, Wen; Fei, Han-Lan; Xiao, Wen

2016-01-01

Dance is a universal art form practiced by all human societies and has many functions including sexual attraction, social cohesion, and the therapeutic release of energy. Dance also has been reported in a small number of non-human primate species, in particular apes. However, its function has not been systematically evaluated. We observed 357 intentional, rhythmic, and nonverbal dance displays performed by four adult female cao vit gibbons (Nomascus nasutus) residing in four polygynous groups during 3000 h of observation in Bangliang, Guangxi, China. Females used dance to solicit copulations, as well as to promote a social bond with the group’s lone adult male. In addition, this display appears to represent a form of non-aggressive competition among adult females living in the same group. We found that a female who had a weaker social relationship with the breeding male increased her social and sexual access to the male by an increase in dancing frequency. Given that gibbons dance in various behavioral contexts, and appears to serve several important social and sexual functions, a greater understanding of this form of gestural communication offers an instructive model for examining the origin and evolution of dance in humans and other apes. PMID:27687686

Simultaneous Cooperation and Competition in the Evolution of Musical Behavior: Sex-Related Modulations of the Singer's Formant in Human Chorusing

PubMed Central

Keller, Peter E.; König, Rasmus; Novembre, Giacomo

2017-01-01

Human interaction through music is a vital part of social life across cultures. Influential accounts of the evolutionary origins of music favor cooperative functions related to social cohesion or competitive functions linked to sexual selection. However, work on non-human “chorusing” displays, as produced by congregations of male insects and frogs to attract female mates, suggests that cooperative and competitive functions may coexist. In such chorusing, rhythmic coordination between signalers, which maximizes the salience of the collective broadcast, can arise through competitive mechanisms by which individual males jam rival signals. Here, we show that mixtures of cooperative and competitive behavior also occur in human music. Acoustic analyses of the renowned St. Thomas Choir revealed that, in the presence of female listeners, boys with the deepest voices enhance vocal brilliance and carrying power by boosting high spectral energy. This vocal enhancement may reflect sexually mature males competing for female attention in a covert manner that does not undermine collaborative musical goals. The evolutionary benefits of music may thus lie in its aptness as a medium for balancing sexually motivated behavior and group cohesion. PMID:28959222

Rhythmic displays of female gibbons offer insight into the origin of dance.

PubMed

Fan, Peng-Fei; Ma, Chang-Yong; Garber, Paul A; Zhang, Wen; Fei, Han-Lan; Xiao, Wen

2016-09-30

Dance is a universal art form practiced by all human societies and has many functions including sexual attraction, social cohesion, and the therapeutic release of energy. Dance also has been reported in a small number of non-human primate species, in particular apes. However, its function has not been systematically evaluated. We observed 357 intentional, rhythmic, and nonverbal dance displays performed by four adult female cao vit gibbons (Nomascus nasutus) residing in four polygynous groups during 3000 h of observation in Bangliang, Guangxi, China. Females used dance to solicit copulations, as well as to promote a social bond with the group's lone adult male. In addition, this display appears to represent a form of non-aggressive competition among adult females living in the same group. We found that a female who had a weaker social relationship with the breeding male increased her social and sexual access to the male by an increase in dancing frequency. Given that gibbons dance in various behavioral contexts, and appears to serve several important social and sexual functions, a greater understanding of this form of gestural communication offers an instructive model for examining the origin and evolution of dance in humans and other apes.

A private ultraviolet channel in visual communication.

PubMed

Cummings, Molly E; Rosenthal, Gil G; Ryan, Michael J

2003-05-07

Although private communication is considered an important diversifying force in evolution, there is little direct behavioural evidence to support this notion. Here, we show that ultraviolet (UV) signalling in northern swordtails (Xiphophorus) affords a channel for communication that is not accessible to their major predator, Astyanax mexicanus, the Mexican tetra. Laboratory and field behavioural experiments with swordtails (X. nigrensis) and predators (A. mexicanus) demonstrate that male UV ornamentation significantly increases their attractiveness to females but not to this predator, which is less sensitive to UV. UV reflectance among swordtail species correlates positively with tetra densities across habitats, and visual contrast estimates suggest that UV signals are highly conspicuous to swordtails in their natural environment. Cross-species comparisons also support the hypothesis that natural selection drives the use of UV communication. We compared two species, one with high (X. nigrensis) and one with low (X. malinche) Mexican tetra densities. Xiphophorus nigrensis males reflect significantly more UV than X. malinche, exhibit significant UV sexual dimorphism, and UV is a salient component of the sexual communication system. In X. malinche, however, males reflect minimally in the UV, there is no UV sexual dimorphism, and UV does not play a part in its communication system.

Age cohort differences in the developmental milestones of gay men.

PubMed

Drasin, Harry; Beals, Kristin P; Elliott, Marc N; Lever, Janet; Klein, David J; Schuster, Mark A

2008-01-01

As the social context in which gay men live changes due to greater visibility, greater acceptance, and easier access to gay subculture, gay males may self-identify and take part in gay social activities at earlier ages than in the past. This study examined whether developmental milestones associated with sexual orientation for gay men have changed over the past several decades. A large and diverse sample of 2,402 gay men who responded to a 1994 survey published in a national magazine provided retrospective information on the age at which they reached individual psychological, social, and sexual behavior developmental milestones. We found evidence that individual psychological and sexual behavior milestones (e.g., awareness of attraction to males, having an orgasm with other male) are slowly moving toward earlier chronological ages (by 1 year of age every 8-25 years, p < 0.05), whereas social milestones (e.g., coming out) are moving more rapidly in a similar direction (by 1 year of age every 2-5 years, p < 0.001). The authors perform an innovative sensitivity test to demonstrate the persistence of the finding after correcting for the bias attributable to underrepresentation of those who have not yet self-identified as gay in such samples.

[Human orgasm from the physiological perspective--part II].

PubMed

Gałecki, Piotr; Depko, Andrzej; Jedrzejewska, Sylwia; Talarowska, Monika

2012-08-01

In contrast to the male orgasm, female orgasm is characterized by high variability and diversity, not only in the general population, but also during the life. Women experience sexual pleasure on many levels: physical, emotional, spiritual and intellectual. Sexual functioning of women and men is determined by many factors. A strong correlation between the state of subjective arousal and genital response (erection) is typical for men. In the case of women important role played: emotions, cognitive interpretation of the situation, age, self-esteem and previous sexual experiences. Among women experience orgasm during intercourse or masturbation is not a goal in itself. Modern approach to the phenomenon of orgasm and sexual education of women, make absence of orgasm as a failure. It becomes a source of low self-esteem, less self-confidence or sense of lack of attractiveness.

Relationships among childhood sex-atypical behavior, spatial ability, handedness, and sexual orientation in men.

PubMed

Cohen, Kenneth M

2002-02-01

Moderate support was obtained in a sample of 101 gay, bisexual, and heterosexual males for the perinatal hormone theory, which hypothesizes that attenuated levels of androgens during critical periods of male fetal development fail to masculinize and defeminize the brain. Affected individuals develop female-typical sexual orientation (assessed here by a pie chart) and cerebral organization, reflected in visual-spatial abilities and gender nonconformity. Handedness, also thought to reflect in utero hormone exposure, was evaluated. Gay and bisexual males reported greater femininity and lesser masculinity than heterosexuals, with bisexuals intermediate in masculinity, suggesting a common biological mediator for homoeroticism and sex atypicality. Among bisexual males, increased masculinity was related to enhanced performance on all spatial tasks. Group mean differences in spatial ability and handedness were not found; however, among bisexuals, poorer visual-spatial performance predicted increased homoeroticism and right-handedness positively correlated with all spatial tasks. If perinatal hormones contribute to a generalized feminization of the brain, the current data indicate that it is most apparent among bisexual males. Sexing of their brains may involve several sexually dimorphic regions that are related in a continuous manner. Inferred cerebral feminization was more circumscribed among gay and heterosexual males, for whom childhood sex atypicality was most highly-distinguishing. Unspecified mechanisms responsible for homoeroticism in them may differ from those that produce same-sex attractions in bisexuals and thus have relatively little impact on other components of cerebral feminization.

Homosexual orientation-from nature, not abuse: A critique of Roberts, Glymour, and Koenen (2013).

PubMed

Rind, Bruce

2013-11-01

Roberts, Glymour, and Koenen (2013), using instrumental variable models, argued that child abuse causes homosexual orientation, defined in part as any same-sex attractions. Their instruments were various negative family environment factors. In their analyses, they found that child sexual abuse (CSA) was more strongly related to homosexual orientation than non-sexual maltreatment was, especially among males. The present commentary therefore focused on male CSA. It is argued that Roberts et al.'s "abuse model" is incorrect and an alternative is presented. Male homosexual behavior is common in primates and has been common in many human societies, such that an evolved human male homosexual potential, with individual variation, can be assumed. Cultural variation has been strongly influenced by cultural norms. In our society, homosexual expression is rare because it is counternormative. The "counternormativity model" offered here holds that negative family environment weakens normative controls and increases counternormative thinking and behavior, which, in combination with sufficient homosexual potential and relevant, reinforcing experiences, can produce a homosexual orientation. This is a benign or positive model (innate potential plus release and reinforcement), in contrast to Roberts et al.'s negative model (abuse plus emotional compensation or cognitive distortion). The abuse model is criticized for being based on the sexual victimological paradigm, which developed to describe the female experience in rape and incest. This poorly fits the gay male experience, as demonstrated in a brief non-clinical literature review. Validly understanding male homosexuality, it is argued, requires the broad perspective, as employed here.

Kisspeptin neurones in the posterodorsal medial amygdala modulate sexual partner preference and anxiety in male mice.

PubMed

Adekunbi, D A; Li, X F; Lass, G; Shetty, K; Adegoke, O A; Yeo, S H; Colledge, W H; Lightman, S L; O'Byrne, K T

2018-03-01

The posterodorsal medial amygdala (MePD) is a neural site in the limbic brain involved in regulating emotional and sexual behaviours. There is, however, limited information available on the specific neuronal cell type in the MePD functionally mediating these behaviours in rodents. The recent discovery of a significant kisspeptin neurone population in the MePD has raised interest in the possible role of kisspeptin and its cognate receptor in sexual behaviour. The present study therefore tested the hypothesis that the MePD kisspeptin neurone population is involved in regulating attraction towards opposite sex conspecifics, sexual behaviour, social interaction and the anxiety response by selectively stimulating these neurones using the novel pharmacosynthetic DREADDs (designer receptors exclusively activated by designer drugs) technique. Adult male Kiss-Cre mice received bilateral stereotaxic injections of a stimulatory DREADD viral construct (AAV-hSyn-DIO-hM 3 D(Gq)-mCherry) targeted to the MePD, with subsequent activation by i.p. injection of clozapine-N-oxide (CNO). Socio-sexual behaviours were assessed in a counter-balanced fashion after i.p. injection of either saline or CNO (5 mg kg -1 ). Selective activation of MePD kisspeptin neurones by CNO significantly increased the time spent by male mice in investigating an oestrous female, as well as the duration of social interaction. Additionally, after CNO injection, the mice appeared less anxious, as indicated by a longer exploratory time in the open arms of the elevated plus maze. However, levels of copulatory behaviour were comparable between CNO and saline-treated controls. These data indicate that DREADD-induced activation of MePD kisspeptin neurones enhances both sexual partner preference in males and social interaction and also decreases anxiety, suggesting a key role played by MePD kisspeptin in sexual motivation and social behaviour. © 2018 The Authors. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of British Society for Neuroendocrinology.

Sexual dimorphism of male face shape, partnership status and the temporal context of relationship sought modulate women's preferences for direct gaze.

PubMed

Conway, Claire A; Jones, Benedict C; DeBruine, Lisa M; Little, Anthony C

2010-02-01

Most previous studies of face preferences have investigated the physical cues that influence face preferences. Far fewer studies have investigated the effects of cues to the direction of others' social interest (i.e. gaze direction) on face preferences. Here we found that unpartnered women demonstrated stronger preferences for direct gaze (indicating social interest) from feminine male faces than from masculine male faces when judging men's attractiveness for long-term relationships, but not when judging men's attractiveness for short-term relationships. Moreover, unpartnered women's preferences for direct gaze from feminine men were stronger for long-term than short-term relationships, but there was no comparable effect for judgements of masculine men. No such effects were evident among women with romantic partners, potentially reflecting different motivations underlying partnered and unpartnered women's judgements of men's attractiveness. Collectively these findings (1) complement previous findings whereby women demonstrated stronger preferences for feminine men as long-term than short-term partners, (2) demonstrate context-sensitivity in the integration of physical and social cues in face preferences, and (3) suggest that gaze preferences may function, at least in part, to facilitate efficient allocation of mating effort.

Assessment of pedophilia using hemodynamic brain response to sexual stimuli.

PubMed

Ponseti, Jorge; Granert, Oliver; Jansen, Olav; Wolff, Stephan; Beier, Klaus; Neutze, Janina; Deuschl, Günther; Mehdorn, Hubertus; Siebner, Hartwig; Bosinski, Hartmut

2012-02-01

Accurately assessing sexual preference is important in the treatment of child sex offenders. Phallometry is the standard method to identify sexual preference; however, this measure has been criticized for its intrusiveness and limited reliability. To evaluate whether spatial response pattern to sexual stimuli as revealed by a change in the blood oxygen level-dependent signal facilitates the identification of pedophiles. During functional magnetic resonance imaging, pedophilic and nonpedophilic participants were briefly exposed to same- and opposite-sex images of nude children and adults. We calculated differences in blood oxygen level-dependent signals to child and adult sexual stimuli for each participant. The corresponding contrast images were entered into a group analysis to calculate whole-brain difference maps between groups. We calculated an expression value that corresponded to the group result for each participant. These expression values were submitted to 2 different classification algorithms: Fisher linear discriminant analysis and κ -nearest neighbor analysis. This classification procedure was cross-validated using the leave-one-out method. Section of Sexual Medicine, Medical School, Christian Albrechts University of Kiel, Kiel, Germany. We recruited 24 participants with pedophilia who were sexually attracted to either prepubescent girls (n = 11) or prepubescent boys (n = 13) and 32 healthy male controls who were sexually attracted to either adult women (n = 18) or adult men (n = 14). Sensitivity and specificity scores of the 2 classification algorithms. The highest classification accuracy was achieved by Fisher linear discriminant analysis, which showed a mean accuracy of 95% (100% specificity, 88% sensitivity). Functional brain response patterns to sexual stimuli contain sufficient information to identify pedophiles with high accuracy. The automatic classification of these patterns is a promising objective tool to clinically diagnose pedophilia.

Sexual identities and lifestyles among non-heterosexual urban Chiang Mai adolescents: implications for health

PubMed Central

Tangmunkongvorakul, Arunrat; Banwell, Cathy; Carmichael, Gordon; Utomo, Iwu Dwisetyani; Sleigh, Adrian

2011-01-01

Drawing upon quantitative and qualitative data we explore perspectives on and experiences of sexual lifestyles and relationships among more than 1,750 adolescents aged 17-20 years who reside in urban Chiang Mai, Thailand. We focus on respondents’ representations and understandings of their sexual/gender identities derived mainly from in-depth interviews and focus group discussions, supplemented with observations and field notes. Our results show that while many young Thais described themselves as heterosexual males or females others described themselves as gay, kathoey, tom, dii, bisexual or something else. Some were still questioning their own identities. The terms gay, kathoey, tom and dii are commonly used by these Thais to describe a range of sexual/gender identities relating to persons who are sexually or romantically attracted to the same biological sex. We use case studies to illustrate the distinctive characterizations, sexual lifestyles and relationships of each of these identities. We conclude that the sexual lifestyles encountered among Northern Thai non-heterosexual adolescents could lead to negative health consequences and indicated a need for improved relationship education, counselling and sensitive sexual health services. PMID:20665299

A Social-Cognitive Analysis of How Young Men Become Involved in Male Escorting

PubMed Central

Smith, Michael D.; Grov, Christian; Seal, David W.; McCall, Peter

2017-01-01

This study employed a social-cognitive theoretical perspective to assess the interactions of behavioral, cognitive, and situational factors to understand better how young male sex workers (MSWs) entered the sex trade industry. As part of a larger project examining male escorts working for a single agency, MSWs (n = 38) were interviewed about their work and personal lives. Interviews were transcribed and analyzed thematically. As predicted by a social-cognitive perspective, results supported reciprocal influences of behavior and environment, environment and cognition, and behavior and cognition. MSWs developed more self-efficacy around sex work behaviors and more positive outcome expectations with experience; moral conflict and lack of attraction to clients limited MSWs’ self-efficacy. Key variables for sex work appeared to be cognitive in nature—mostly represented by a decreased commitment to normative social-sexual values, the specific nature of which may have varied by sexual orientation. Findings support the contention that social-cognitive theory can effectively model entry of young men into sex work. Social-cognitive theory provides a broad umbrella underneath which various explanations for male sex work can be gathered. PMID:22880726

The effects of gender, ethnicity, and a close relationship theme on perceptions of persons introducing a condom.

PubMed

Castaneda, D M; Collins, B E

1998-09-01

Perceptions of persons who introduce condoms in an ongoing sexual interaction, and the effects of gender and ethnicity on these perceptions, were explored in a study involving 243 students at a large, urban university in the western US. 133 of these students identified themselves as Mexican American; the remaining students indicated they were White. A vignette methodology was used to elicit perceptions of condom introducers on six scales (Nice, Exciting, Sexually Attractive, Promiscuous, Good Relationship Partner, Unpersonable/Personable). Data were analyzed in a 2 (gender of participant) x 2 (gender of condom introducer) x 3 (low acculturated Mexican American, high acculturated Mexican American, White) x 2 (presence/absence of close relationship theme) analysis of variance and covariance. In terms of the Nice Scale, women rated condom introducers significantly higher than men, female condom introducers were rated significantly higher than male introducers, and condom introducers who expressed a care and responsibility theme while introducing a condom were rated significantly higher than those who expressed no theme. On the Exciting Scale, women condom introducers were rated significantly higher than men. Condom introducers who expressed a care and responsibility theme were rated significantly higher than those who expressed no theme on the Good Relationship Partner scale. Men rated the female condom introducer significantly higher than women on the Promiscuous scale. Low acculturated Mexicans rated the female condom introducer significantly higher than the male introducer on the Promiscuous scale and rated the condom introducer significantly higher than Whites on the Sexually Attractive scale. These findings attest that many often contradictory interpersonal gender- and ethnicity-related perceptions operate in sexual encounters.

Sexual identity, sexual attraction and sexual experience: the Second Australian Study of Health and Relationships.

PubMed

Richters, Juliet; Altman, Dennis; Badcock, Paul B; Smith, Anthony M A; de Visser, Richard O; Grulich, Andrew E; Rissel, Chris; Simpson, Judy M

2014-11-01

Background Behavioural and other aspects of sexuality are not always consistent. This study describes the prevalence and overlap of same-sex and other-sex attraction and experience and of different sexual identities in Australia. Computer-assisted telephone interviews were completed by a representative sample of 20094 men and women aged 16-69 years recruited by landline and mobile phone random-digit dialling with a response rate (participation rate among eligible people) of 66.2%. Respondents were asked about their sexual identity ('Do you think of yourself as' heterosexual/straight, homosexual/gay, bisexual, etc.) and the sex of people with whom they had ever had sexual contact and to whom they had felt sexually attracted. Men and women had different patterns of sexual identity. Although the majority of people identified as heterosexual (97% men, 96% women), women were more likely than men to identify as bisexual. Women were less likely than men to report exclusively other-sex or same-sex attraction and experience; 9% of men and 19% of women had some history of same-sex attraction and/or experience. Sexual attraction and experience did not necessarily correspond. Homosexual/gay identity was more common among men with tertiary education and living in cities and less common among men with blue-collar jobs. Many gay men (53%) and lesbians (76%) had some experience with an other-sex partner. More women identified as lesbian or bisexual than in 2001-02. Similarly, more women reported same-sex experience and same-sex attraction. In Australia, men are more likely than women to report exclusive same-sex attraction and experience, although women are more likely than men to report any non-heterosexual identity, experience and attraction. Whether this is a feature of the plasticity of female sexuality or due to lesser stigma than for men is unknown.

Facial Features: What Women Perceive as Attractive and What Men Consider Attractive.

PubMed

Muñoz-Reyes, José Antonio; Iglesias-Julios, Marta; Pita, Miguel; Turiegano, Enrique

2015-01-01

Attractiveness plays an important role in social exchange and in the ability to attract potential mates, especially for women. Several facial traits have been described as reliable indicators of attractiveness in women, but very few studies consider the influence of several measurements simultaneously. In addition, most studies consider just one of two assessments to directly measure attractiveness: either self-evaluation or men's ratings. We explored the relationship between these two estimators of attractiveness and a set of facial traits in a sample of 266 young Spanish women. These traits are: facial fluctuating asymmetry, facial averageness, facial sexual dimorphism, and facial maturity. We made use of the advantage of having recently developed methodologies that enabled us to measure these variables in real faces. We also controlled for three other widely used variables: age, body mass index and waist-to-hip ratio. The inclusion of many different variables allowed us to detect any possible interaction between the features described that could affect attractiveness perception. Our results show that facial fluctuating asymmetry is related both to self-perceived and male-rated attractiveness. Other facial traits are related only to one direct attractiveness measurement: facial averageness and facial maturity only affect men's ratings. Unmodified faces are closer to natural stimuli than are manipulated photographs, and therefore our results support the importance of employing unmodified faces to analyse the factors affecting attractiveness. We also discuss the relatively low equivalence between self-perceived and male-rated attractiveness and how various anthropometric traits are relevant to them in different ways. Finally, we highlight the need to perform integrated-variable studies to fully understand female attractiveness.

Facial Features: What Women Perceive as Attractive and What Men Consider Attractive

PubMed Central

Muñoz-Reyes, José Antonio; Iglesias-Julios, Marta; Pita, Miguel; Turiegano, Enrique

2015-01-01

Attractiveness plays an important role in social exchange and in the ability to attract potential mates, especially for women. Several facial traits have been described as reliable indicators of attractiveness in women, but very few studies consider the influence of several measurements simultaneously. In addition, most studies consider just one of two assessments to directly measure attractiveness: either self-evaluation or men's ratings. We explored the relationship between these two estimators of attractiveness and a set of facial traits in a sample of 266 young Spanish women. These traits are: facial fluctuating asymmetry, facial averageness, facial sexual dimorphism, and facial maturity. We made use of the advantage of having recently developed methodologies that enabled us to measure these variables in real faces. We also controlled for three other widely used variables: age, body mass index and waist-to-hip ratio. The inclusion of many different variables allowed us to detect any possible interaction between the features described that could affect attractiveness perception. Our results show that facial fluctuating asymmetry is related both to self-perceived and male-rated attractiveness. Other facial traits are related only to one direct attractiveness measurement: facial averageness and facial maturity only affect men's ratings. Unmodified faces are closer to natural stimuli than are manipulated photographs, and therefore our results support the importance of employing unmodified faces to analyse the factors affecting attractiveness. We also discuss the relatively low equivalence between self-perceived and male-rated attractiveness and how various anthropometric traits are relevant to them in different ways. Finally, we highlight the need to perform integrated-variable studies to fully understand female attractiveness. PMID:26161954

Sexual Attraction and Harassment: Management's New Problems.

ERIC Educational Resources Information Center

Driscoll, Jeanne Bosson

1981-01-01

Both sexual attraction and harassment must be dealt with if men and women are to develop truly productive working relationships. Key issues include policies on sexual attraction and harassment, availability of professional resources on the subjects, training, and the role of personnel specialists. (CT)

Endocrine control of sexual behavior in sneaker males of the peacock blenny Salaria pavo: effects of castration, aromatase inhibition, testosterone and estradiol.

PubMed

Gonçalves, David; Alpedrinha, João; Teles, Magda; Oliveira, Rui F

2007-04-01

The effects of castration and sex steroid manipulations on the expression of sexual behavior were investigated in a small fish, the peacock blenny, Salaria pavo. In this species, large males defend nests and attract females while small "sneaker" males reproduce by imitating the female morphology and courtship behavior in order to approach nests during spawning events and parasitically fertilize eggs. Sneakers switch into nest holders in their second breeding season, thus displaying both male and female-like sexual behavior during their lifetime. We tested the effects of castration and of an aromatase inhibitor (Fadrozole, F), testosterone (T) or 17beta-estradiol (E(2)) implants on the expression of male and female-like behavior in sneakers. Sneakers were either sham-operated, castrated or castrated and implanted with vehicle, F, T+F or E(2)+F. Seven days after the treatment, sneakers were placed in a tank with a nesting male, two ripe females and an available nest. Castrated fish had lower levels of circulating T and increased the time spent displaying female typical nuptial coloration. T implants had the opposite effect, inhibiting the expression of female-like behavior and coloration. E(2) implants had no significant effect on the display of sexual behavior but the frequency of aggressive displays decreased. The results agree with previous findings in sneakers of S. pavo that demonstrated an inhibition of female-like behavior by 11-ketotestosterone (11-KT). The reported increase in T and 11-KT production when sneakers change into nest holders may thus contribute to behaviorally defeminize sneakers. Contrarily, both T and E(2) failed to promote male-like behavior, suggesting that behavioral masculization during tactic switching depends on other neuroendocrine mechanisms or that the time length of the experiment was insufficient to induce male-like behavioral changes in sneakers.

Differences in Sexual Orientation Diversity and Sexual Fluidity in Attractions among Gender Minority Adults in Massachusetts

PubMed Central

Katz-Wise, Sabra L.; Reisner, Sari L.; White, Jaclyn M.; Keo-Meier, Colton L.

2015-01-01

This study characterized sexual orientation identities and sexual fluidity in attractions in a community-based sample of self-identified transgender and gender nonconforming adults in Massachusetts. Participants were recruited in 2013 using bi-model methods (online and in-person) to complete a one-time web-based quantitative survey that included questions about sexual orientation identity and sexual fluidity. Multivariable logistic regression models estimated Adjusted Risk Ratios (aRR) and 95% Confidence Intervals (95% CI) to examine the correlates of self-reported changes in attractions ever in lifetime among the whole sample (n=452) and after transition among those who reported social gender transition (n=205). The sample endorsed diverse sexual orientation identities: 42.7% queer, 19.0% other non-binary, 15.7% bisexual, 12.2% straight, 10.4% gay/lesbian. Overall, 58.2% reported having experienced changes in sexual attractions in their lifetime. In adjusted models, trans masculine individuals were more likely than trans feminine individuals to report sexual fluidity in their lifetime (aRR=1.69; 95% CI=1.34, 2.12). Among those who transitioned, 64.6% reported a change in attractions post-transition and trans masculine individuals were less likely than trans feminine individuals to report sexual fluidity (aRR=0.44; 95% CI=0.28, 0.69). Heterogeneity of sexual orientation identities and sexual fluidity in attractions are the norm rather than the exception among gender minority people. PMID:26156113

Patterns of Eye Movements When Observers Judge Female Facial Attractiveness

PubMed Central

Zhang, Yan; Wang, Xiaoying; Wang, Juan; Zhang, Lili; Xiang, Yu

2017-01-01

The purpose of the present study is to explore the fixed model for the explicit judgments of attractiveness and infer which features are important to judge the facial attractiveness. Behavioral studies on the perceptual cues for female facial attractiveness implied three potentially important features: averageness, symmetry, and sexual dimorphy. However, these studies did not explained which regions of facial images influence the judgments of attractiveness. Therefore, the present research recorded the eye movements of 24 male participants and 19 female participants as they rated a series of 30 photographs of female facial attractiveness. Results demonstrated the following: (1) Fixation is longer and more frequent on the noses of female faces than on their eyes and mouths (no difference exists between the eyes and the mouth); (2) The average pupil diameter at the nose region is bigger than that at the eyes and mouth (no difference exists between the eyes and the mouth); (3) the number of fixations of male participants was significantly more than female participants. (4) Observers first fixate on the eyes and mouth (no difference exists between the eyes and the mouth) before fixating on the nose area. In general, participants attend predominantly to the nose to form attractiveness judgments. The results of this study add a new dimension to the existing literature on judgment of facial attractiveness. The major contribution of the present study is the finding that the area of the nose is vital in the judgment of facial attractiveness. This finding establish a contribution of partial processing on female facial attractiveness judgments during eye-tracking. PMID:29209242

Patterns of Eye Movements When Observers Judge Female Facial Attractiveness.

PubMed

Zhang, Yan; Wang, Xiaoying; Wang, Juan; Zhang, Lili; Xiang, Yu

2017-01-01

The purpose of the present study is to explore the fixed model for the explicit judgments of attractiveness and infer which features are important to judge the facial attractiveness. Behavioral studies on the perceptual cues for female facial attractiveness implied three potentially important features: averageness, symmetry, and sexual dimorphy. However, these studies did not explained which regions of facial images influence the judgments of attractiveness. Therefore, the present research recorded the eye movements of 24 male participants and 19 female participants as they rated a series of 30 photographs of female facial attractiveness. Results demonstrated the following: (1) Fixation is longer and more frequent on the noses of female faces than on their eyes and mouths (no difference exists between the eyes and the mouth); (2) The average pupil diameter at the nose region is bigger than that at the eyes and mouth (no difference exists between the eyes and the mouth); (3) the number of fixations of male participants was significantly more than female participants. (4) Observers first fixate on the eyes and mouth (no difference exists between the eyes and the mouth) before fixating on the nose area. In general, participants attend predominantly to the nose to form attractiveness judgments. The results of this study add a new dimension to the existing literature on judgment of facial attractiveness. The major contribution of the present study is the finding that the area of the nose is vital in the judgment of facial attractiveness. This finding establish a contribution of partial processing on female facial attractiveness judgments during eye-tracking.

Brain and gonadal aromatase activity and steroid hormone levels in female and polymorphic males of the peacock blenny Salaria pavo.

PubMed

Gonçalves, David; Teles, Magda; Alpedrinha, João; Oliveira, Rui F

2008-11-01

In the peacock blenny Salaria pavo large males with well-developed secondary sexual characters establish nests and attract females while small "sneaker" males mimic female sexual displays in order to approach the nests of larger males and parasitically fertilize eggs. These alternative reproductive tactics are sequential, as sneakers irreversibly switch into nesting males. This transition involves major morphologic and behavioral changes and is likely to be mediated by hormones. This study focuses on the role of aromatase, an enzyme that catalyses the conversion of androgens into estrogens, in the regulation of male sexual polymorphism in S. pavo. For this, sex steroid plasma levels and aromatase activity (AA) in gonads, whole brain and brain macroareas were determined in sneakers, transitional males (i.e. sneakers undergoing the transition into nesting males), nesting males and females collected in the field. AA was much higher in ovarian tissue than in testicular tissue and accordingly circulating estradiol levels were highest in females. This supports the view that elevated AA and estradiol levels are associated with the development of a functional ovary. Transitional males are in a non-reproductive phase and had underdeveloped testes when compared with sneakers and nesting males. Testicular AA was approximately 10 times higher in transitional males when compared with sneakers and nesting males, suggesting high AA has a suppressive effect on testicular development. Nesting males had significantly higher plasma levels of both testosterone (T) and 11-ketotestosterone when compared with the other male morphs and previous studies demonstrated that these androgens suppress female-like displays in sneakers. In the brain, AA was highest in macroareas presumably containing hypothalamic nuclei traditionally associated with the regulation of reproductive behaviors. Overall, females presented the highest levels of brain AA. In male morphs AA increased from sneakers, to transitional males, to nesting males in all brain macroareas. These results suggest that the transition into the nesting male tactic is accompanied both by an increase in testicular androgen production and by a higher conversion of androgens into estrogens in the brain. The increase in androgen production is likely to mediate the development of male secondary sexual characters while the increase in brain AA may be related to the behavioral changes associated with tactic transition.

Scrutinizing Immutability: Research on Sexual Orientation and U.S. Legal Advocacy for Sexual Minorities.

PubMed

Diamond, Lisa M; Rosky, Clifford J

2016-01-01

We review scientific research and legal authorities to argue that the immutability of sexual orientation should no longer be invoked as a foundation for the rights of individuals with same-sex attractions and relationships (i.e., sexual minorities). On the basis of scientific research as well as U.S. legal rulings regarding lesbian, gay, and bisexual (LGB) rights, we make three claims: First, arguments based on the immutability of sexual orientation are unscientific, given what we now know from longitudinal, population-based studies of naturally occurring changes in the same-sex attractions of some individuals over time. Second, arguments based on the immutability of sexual orientation are unnecessary, in light of U.S. legal decisions in which courts have used grounds other than immutability to protect the rights of sexual minorities. Third, arguments about the immutability of sexual orientation are unjust, because they imply that same-sex attractions are inferior to other-sex attractions, and because they privilege sexual minorities who experience their sexuality as fixed over those who experience their sexuality as fluid. We conclude that the legal rights of individuals with same-sex attractions and relationships should not be framed as if they depend on a certain pattern of scientific findings regarding sexual orientation.

Autogynephilia: an underappreciated paraphilia.

PubMed

Lawrence, Anne A

2011-01-01

Autogynephilia is defined as a male's propensity to be sexually aroused by the thought of himself as a female. It is the paraphilia that is theorized to underlie transvestism and some forms of male-to-female (MtF) transsexualism. Autogynephilia encompasses sexual arousal with cross-dressing and cross-gender expression that does not involve women's clothing per se. The concept of autogynephilia defines a typology of MtF transsexualism and offers a theory of motivation for one type of MtF transsexualism. Autogynephilia resembles a sexual orientation in that it involves elements of idealization and attachment as well as erotic desire. Nearly 3% of men in Western countries may experience autogynephilia; its most severe manifestation, MtF transsexualism, is rare but increasing in prevalence. Some theorists and clinicians reject the transsexual typology and theory of motivation derived from autogynephilia; their objections suggest a need for additional research. The concept of autogynephilia can assist clinicians in understanding some otherwise puzzling manifestations of nonhomosexual MtF transsexualism. Autogynephilia exemplifies an unusual paraphilic category called 'erotic target identity inversions', in which men desire to impersonate or turn their bodies into facsimiles of the persons or things to which they are sexually attracted. Copyright © 2011 S. Karger AG, Basel.

Beyond magic traits: Multimodal mating cues in Heliconius butterflies.

PubMed

Mérot, Claire; Frérot, Brigitte; Leppik, Ene; Joron, Mathieu

2015-11-01

Species coexistence involves the evolution of reproductive barriers opposing gene flow. Heliconius butterflies display colorful patterns affecting mate choice and survival through warning signaling and mimicry. These patterns are called "magic traits" for speciation because divergent natural selection may promote mimicry shifts in pattern whose role as mating cue facilitates reproductive isolation. By contrast, between comimetic species, natural selection promotes pattern convergence. We addressed whether visual convergence interferes with reproductive isolation by testing for sexual isolation between two closely related species with similar patterns, H. timareta thelxinoe and H. melpomene amaryllis. Experiments with models confirmed visual attraction based on wing phenotype, leading to indiscriminate approach. Nevertheless, mate choice experiments showed assortative mating. Monitoring male behavior toward live females revealed asymmetry in male preference, H. melpomene males courting both species equally while H. timareta males strongly preferred conspecifics. Experiments with hybrid males suggested an important genetic component for such asymmetry. Behavioral observations support a key role for short-distance cues in determining male choice in H. timareta. Scents extracts from wings and genitalia revealed interspecific divergence in chemical signatures, and hybrid female scent composition was significantly associated with courtship intensity by H. timareta males, providing candidate chemical mating cues involved in sexual isolation. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Vitamin E Supplementation Increases the Attractiveness of Males' Scent for Female European Green Lizards

PubMed Central

Kopena, Renáta; Martín, José; López, Pilar; Herczeg, Gábor

2011-01-01

Background In spite that chemoreception is important in sexual selection for many animals, such as reptiles, the mechanisms that confer reliability to chemical signals are relatively unknown. European green lizards (Lacerta viridis) have substantial amounts of α-tocopherol ( = vitamin E) in their femoral secretions. Because vitamin E is metabolically important and can only be attained from the diet, its secretion is assumed to be costly. However, its role in intraspecific communication is unknown. Methodology/Principal Findings Here, we experimentally show that male European green lizards that received a dietary supplement of vitamin E increased proportions of vitamin E in their femoral secretions. Furthermore, our experiments revealed that females preferred to use areas scent marked by males with experimentally increased vitamin E levels in their secretions. Finally, female preferences were stronger when vitamin E differences between a pair of males' secretions were larger. Conclusions/Significance Our results demonstrate that female green lizards are able to discriminate between males based on the vitamin E content of the males' femoral secretions. We suggest that the possible cost of allocating vitamin E to secretions, which might be dependent on male quality, may be a mechanism that confers reliability to scent marks of green lizards and allows their evolution as sexual signals. PMID:21552540

When mothers make sons sexy: maternal effects contribute to the increased sexual attractiveness of extra-pair offspring.

PubMed

Tschirren, Barbara; Postma, Erik; Rutstein, Alison N; Griffith, Simon C

2012-03-22

Quality differences between offspring sired by the social and by an extra-pair partner are usually assumed to have a genetic basis, reflecting genetic benefits of female extra-pair mate choice. In the zebra finch (Taeniopygia guttata), we identified a colour ornament that is under sexual selection and appears to have a heritable basis. Hence, by engaging in extra-pair copulations with highly ornamented males, females could, in theory, obtain genes for increased offspring attractiveness. Indeed, sons sired by extra-pair partners had larger ornaments, seemingly supporting the genetic benefit hypothesis. Yet, when comparing ornament size of the social and extra-pair partners, there was no difference. Hence, the observed differences most likely had an environmental basis, mediated, for example, via differential maternal investment of resources into the eggs fertilized by extra-pair and social partners. Such maternal effects may (at least partly) be mediated by egg size, which we found to be associated with mean ornament expression in sons. Our results are consistent with the idea that maternal effects can shape sexual selection by altering the genotype-phenotype relationship for ornamentation. They also caution against automatically attributing greater offspring attractiveness or viability to an extra-pair mate's superior genetic quality, as without controlling for differential maternal investment we may significantly overestimate the role of genetic benefits in the evolution of extra-pair mating behaviour.

When mothers make sons sexy: maternal effects contribute to the increased sexual attractiveness of extra-pair offspring

PubMed Central

Tschirren, Barbara; Postma, Erik; Rutstein, Alison N.; Griffith, Simon C.

2012-01-01

Quality differences between offspring sired by the social and by an extra-pair partner are usually assumed to have a genetic basis, reflecting genetic benefits of female extra-pair mate choice. In the zebra finch (Taeniopygia guttata), we identified a colour ornament that is under sexual selection and appears to have a heritable basis. Hence, by engaging in extra-pair copulations with highly ornamented males, females could, in theory, obtain genes for increased offspring attractiveness. Indeed, sons sired by extra-pair partners had larger ornaments, seemingly supporting the genetic benefit hypothesis. Yet, when comparing ornament size of the social and extra-pair partners, there was no difference. Hence, the observed differences most likely had an environmental basis, mediated, for example, via differential maternal investment of resources into the eggs fertilized by extra-pair and social partners. Such maternal effects may (at least partly) be mediated by egg size, which we found to be associated with mean ornament expression in sons. Our results are consistent with the idea that maternal effects can shape sexual selection by altering the genotype–phenotype relationship for ornamentation. They also caution against automatically attributing greater offspring attractiveness or viability to an extra-pair mate's superior genetic quality, as without controlling for differential maternal investment we may significantly overestimate the role of genetic benefits in the evolution of extra-pair mating behaviour. PMID:21957136

Social Networks and Sexual Orientation Disparities in Tobacco and Alcohol Use

PubMed Central

Hatzenbuehler, Mark L; McLaughlin, Katie A; Xuan, Ziming

2015-01-01

Objective: The purpose of this study was to examine whether the composition of social networks contributes to sexual orientation disparities in substance use and misuse. Method: Data were obtained from the National Longitudinal Study of Adolescent Health (Add Health), a nationally representative cohort study of adolescents (N = 20,745). Wave 1 collected extensive information about the social networks of participants through peer nomination inventories. Results: Same- and both-sex–attracted youths had higher frequency/quantity of tobacco use in their peer networks than did opposite-sex–attracted youths, and both-sex–attracted youths had higher frequency/quantity of alcohol use and misuse in their peer networks than opposite-sex–attracted youths. Among same- and both-sex–attracted youths, greater frequency/quantity of tobacco use in one’s social network predicted greater use of cigarettes. In addition, greater frequency/quantity of peers’ drinking and drinking to intoxication predicted more alcohol use and alcohol misuse in the both-sex–attracted group. These social network factors mediated sexual orientation–related disparities in tobacco use for both- and same-sex–attracted youths. Moreover, sexual orientation disparities in alcohol misuse were mediated by social network characteristics for the same-sex and both-sex–attracted youths. Importantly, sexual minority adolescents were no more likely to have other sexual minorities in their social networks than were sexual majority youths, ruling out an alternative explanation for our results. Conclusions: These findings highlight the importance of social networks as correlates of substance use behaviors among sexual minority youths and as potential pathways explaining sexual orientation disparities in substance use outcomes. PMID:25486400

A Biocultural Investigation of Gender Differences in Tobacco Use in an Egalitarian Hunter-Gatherer Population.

PubMed

Roulette, Casey J; Hagen, Edward; Hewlett, Barry S

2016-06-01

In the developing world, the dramatic male bias in tobacco use is usually ascribed to pronounced gender disparities in social, political, or economic power. This bias might also reflect under-reporting by woman and/or over-reporting by men. To test the role of gender inequality on gender differences in tobacco use we investigated tobacco use among the Aka, a Congo Basin foraging population noted for its exceptionally high degree of gender equality. We also tested a sexual selection hypothesis-that Aka men's tobacco use is related to risk taking. Tobacco use, income, tobacco purchases, tobacco sharing, reasons for using tobacco, risk taking, and other variables were measured using structured surveys and peer reports. Tobacco use was verified by testing for salivary cotinine, a nicotine metabolite. Contrary to expectations, we found a very large male bias in tobacco use. Low levels of use among females appeared to be explained by aversions to tobacco, concerns over its negative effects on fetal health, and a desire to attract husbands, who prefer nonsmoking wives. High male use appeared to be related to a desire to enhance hunting abilities and attract and/or retain wives, who prefer husbands that smoke. We conclude that low levels of smoking by Aka women are better explained by the hypothesis that women evolved to avoid plant toxins to protect their fetuses and nursing infants. High male use might be better explained by sexual selection. We also highlight the important role that recreational drugs appear to play in hunter-gatherer sharing relationships.

Pedophilia, hebephilia, and the DSM-V.

PubMed

Blanchard, Ray; Lykins, Amy D; Wherrett, Diane; Kuban, Michael E; Cantor, James M; Blak, Thomas; Dickey, Robert; Klassen, Philip E

2009-06-01

The term pedophilia denotes the erotic preference for prepubescent children. The term hebephilia has been proposed to denote the erotic preference for pubescent children (roughly, ages 11 or 12-14), but it has not become widely used. The present study sought to validate the concept of hebephilia by examining the agreement between self-reported sexual interests and objectively recorded penile responses in the laboratory. The participants were 881 men who were referred for clinical assessment because of paraphilic, criminal, or otherwise problematic sexual behavior. Within-group comparisons showed that men who verbally reported maximum sexual attraction to pubescent children had greater penile responses to depictions of pubescent children than to depictions of younger or older persons. Between-groups comparisons showed that penile responding distinguished such men from those who reported maximum attraction to prepubescent children and from those who reported maximum attraction to fully grown persons. These results indicated that hebephilia exists as a discriminable erotic age-preference. The authors recommend various ways in which the DSM might be altered to accommodate the present findings. One possibility would be to replace the diagnosis of Pedophilia with Pedohebephilia and allow the clinician to specify one of three subtypes: Sexually Attracted to Children Younger than 11 (Pedophilic Type), Sexually Attracted to Children Age 11-14 (Hebephilic Type), or Sexually Attracted to Both (Pedohebephilic Type). We further recommend that the DSM-V encourage users to record the typical age of children who most attract the patient sexually as well as the gender of children who most attract the patient sexually.

Imperfect chemical female mimicry in males of the ant Cardiocondyla obscurior

NASA Astrophysics Data System (ADS)

Cremer, Sylvia; D'Ettorre, Patrizia; Drijfhout, Falko P.; Sledge, Matthew F.; Turillazzi, Stefano; Heinze, Jürgen

2008-11-01

Winged and wingless males coexist in the ant Cardiocondyla obscurior. Wingless (“ergatoid”) males never leave their maternal colony and fight remorselessly among each other for the access to emerging females. The peaceful winged males disperse after about 10 days, but beforehand also mate in the nest. In the first 5 days of their life, winged males perform a chemical female mimicry that protects them against attack and even makes them sexually attractive to ergatoid males. When older, the chemical profile of winged males no longer matches that of virgin females; nevertheless, they are still tolerated, which so far has been puzzling. Contrasting this general pattern, we have identified a single aberrant colony in which all winged males were attacked and killed by the ergatoid males. A comparative analysis of the morphology and chemical profile of these untypical attacked winged males and the tolerated males from several normal colonies revealed that normal old males are still performing some chemical mimicry to the virgin queens, though less perfect than in their young ages. The anomalous attacked winged males, on the other hand, had a very different odour to the females. Our study thus exemplifies that the analysis of rare malfunctioning can add valuable insight on functioning under normal conditions and allows the conclusion that older winged males from normal colonies of the ant C. obscurior are guarded through an imperfect chemical female mimicry, still close enough to protect against attacks by the wingless fighters yet dissimilar enough not to elicit their sexual interest.

Consequences of Beauty: Effects of Rater Sex and Sexual Orientation on the Visual Exploration and Evaluation of Attractiveness in Real World Scenes

PubMed Central

Mitrovic, Aleksandra; Tinio, Pablo P. L.; Leder, Helmut

2016-01-01

One of the key behavioral effects of attractiveness is increased visual attention to attractive people. This effect is often explained in terms of evolutionary adaptations, such as attractiveness being an indicator of good health. Other factors could influence this effect. In the present study, we explored the modulating role of sexual orientation on the effects of attractiveness on exploratory visual behavior. Heterosexual and homosexual men and women viewed natural-looking scenes that depicted either two women or two men who varied systematically in levels of attractiveness (based on a pre-study). Participants’ eye movements and attractiveness ratings toward the faces of the depicted people were recorded. The results showed that although attractiveness had the largest influence on participants’ behaviors, participants’ sexual orientations strongly modulated the effects. With the exception of homosexual women, all participant groups looked longer and more often at attractive faces that corresponded with their sexual orientations. Interestingly, heterosexual and homosexual men and homosexual women looked longer and more often at the less attractive face of their non-preferred sex than the less attractive face of their preferred sex, evidence that less attractive faces of the preferred sex might have an aversive character. These findings provide evidence for the important role that sexual orientation plays in guiding visual exploratory behavior and evaluations of the attractiveness of others. PMID:27047365

Consequences of Beauty: Effects of Rater Sex and Sexual Orientation on the Visual Exploration and Evaluation of Attractiveness in Real World Scenes.

PubMed

Mitrovic, Aleksandra; Tinio, Pablo P L; Leder, Helmut

2016-01-01

One of the key behavioral effects of attractiveness is increased visual attention to attractive people. This effect is often explained in terms of evolutionary adaptations, such as attractiveness being an indicator of good health. Other factors could influence this effect. In the present study, we explored the modulating role of sexual orientation on the effects of attractiveness on exploratory visual behavior. Heterosexual and homosexual men and women viewed natural-looking scenes that depicted either two women or two men who varied systematically in levels of attractiveness (based on a pre-study). Participants' eye movements and attractiveness ratings toward the faces of the depicted people were recorded. The results showed that although attractiveness had the largest influence on participants' behaviors, participants' sexual orientations strongly modulated the effects. With the exception of homosexual women, all participant groups looked longer and more often at attractive faces that corresponded with their sexual orientations. Interestingly, heterosexual and homosexual men and homosexual women looked longer and more often at the less attractive face of their non-preferred sex than the less attractive face of their preferred sex, evidence that less attractive faces of the preferred sex might have an aversive character. These findings provide evidence for the important role that sexual orientation plays in guiding visual exploratory behavior and evaluations of the attractiveness of others.

The influence of attraction to partner on heterosexual women's sexual and relationship satisfaction in long-term relationships.

PubMed

Mark, Kristen P; Herbenick, Debby

2014-04-01

Previous research has consistently found that attraction is important in the formation of relationships though research on attraction in long-term relationships is less well understood. This article examined the predictive value of self-reported attraction to partner and change in attraction to partner on sexual and relationship satisfaction in 176 women in committed heterosexual relationships using online survey methodology. Participants' age ranged from 21 to 56 (M = 34.5) years and their relationship length ranged from 5 to 35 (M = 11.75) years. Hierarchical multiple regression results indicated that change in attraction to partner was the most salient predictor of sexual satisfaction, with current attraction to partner also related to women's sexual satisfaction, accounting for 20 % of the variance. Current attraction to partner was the only significant predictor of women's relationship satisfaction, accounting for 22 % of the variance. Additionally, attraction variables accounted for variance above and beyond the impact of relationship and sexual satisfaction. These findings suggest that self-reported attraction to partner is an important contributor to women's satisfaction outcomes in long-term relationships. Further studies in the area of attraction to partner that include couple dynamics and longitudinal data are encouraged and implications for therapists, clinicians, and educators are discussed.

Facilitators and Barriers to Participation in PrEP HIV Prevention Trials Involving Transgender Male and Female Adolescents and Emerging Adults

PubMed Central

Fisher, Celia B.; Fried, Adam L.; Desmond, Margaret; Macapagal, Kathryn; Mustanski, Brian

2018-01-01

Despite the disproportionate burden of HIV facing transgender youth, they continue to be under-represented in studies designed to provide an empirical basis for pre-exposure prophylaxis (PrEP) programs that can meet the unique needs of this population. This study examined facilitators and barriers to participation in a PrEP adherence study. Ninety transgender male (TM) and 60 transgender female (TF) 14 – 21 year olds attracted to cisgender male sexual partners completed an online survey to examine (a) gender identity, age and family disclosure; (b) sexual experience, HIV/STI testing history and perceptions of HIV risk; (c) prior health services and (d) perceived PrEP research risks and benefits (e) and the relationship of these factors to the likelihood of study participation. Approximately 50% were likely to participate in the PrEP study. Participation facilitators included prior sexual and health service experiences (i.e. number of sexual partners, STI testing history, comfort discussing sexual orientation and HIV protection with health providers) and study access to PrEP and health services (i.e. daily HIV protection, not having to rely on a partner for protection, regular health check ups). Participation barriers included lack of concern about HIV, potential medication side effects, the logistics of quarterly meetings, remembering to take PrEP daily and reluctance to discuss gender identity with study staff. Requiring guardian consent was a participation barrier for youth under 18. Results suggest that successful recruitment and retention of transgender youth in PrEP prevention studies warrant protocols designed to address youth's underestimation of HIV risk, concerns regarding medical risk and study logistics, and their need for gender and sexual orientation affirming health services. PMID:28650227

Young Africans' representations of the origins of same-sex attraction and implications for sexual and mental health.

PubMed

Winskell, Kate; Sabben, Gaëlle; Pruitt, Kaitlyn L; Allen, Kristi; Findlay, Trinity; Stephenson, Rob

2017-03-01

Sexual minorities are stigmatised in much of sub-Saharan Africa, restricting their access to sexual health services and undermining their mental health. Although public attitudes and social representations inform the experience of sexual stigma, little is known about how young Africans make sense of sexual diversity. We conducted a thematic analysis of 56 texts contributed by young people from 10 countries in response to a prompt in a scriptwriting competition inviting participants to 'tell a story about someone who is attracted to people of the same sex'. We analysed accounts of the origins of same-sex attraction, a prominent theme in the narratives. Two-thirds of the texts provide an explicit or implicit explanation, presenting same-sex attraction as innate (15/38) and/or the consequence of environmental influences (32/38), including parental behaviour, gender separation, trauma, foreign influences and evil spirits. Expressions of the potential to avert or cure same-sex attraction are common. Young people's sense-making around sexual diversity draws on available sociocultural and symbolic resources, some of which may be highly stigmatising, and reflects local, national and transnational influences. The need to explain same-sex attraction and the preponderance of harmful explanatory frameworks compounds sexual minority youth's vulnerability to sexual stigma, harmful coping strategies and mental health challenges.

Gender Preference in the Sexual Attractions, Fantasies, and Relationships of Voluntarily Castrated Men.

PubMed

Handy, Ariel B; Jackowich, Robyn A; Wibowo, Erik; Johnson, Thomas Wayne; Wassersug, Richard J

2016-03-01

Some men seek castration outside a clear medical need. This study explored how their sexuality changed after castration. To explore changes in preferred gender(s) of sexual attraction, fantasy, and relationships in voluntarily castrated men with or without gonadal hormone therapy. A questionnaire was posted at http://www.eunuch.org that yielded data on men who had been voluntarily castrated physically (n = 198) or chemically (n = 96). Respondents were asked to report retrospectively on their sexuality, including their sexual activity and which gender(s) they were sexually attracted to, fantasized about, or had sexual relations with 6 months to 1 year before and after castration. A substantial proportion of men remained sexually active after castration; 37% had sex at least several times per week. Most respondents did not report a change in preferred gender(s) of attraction (65%, n = 181), fantasies (62%, n = 169), or sexual relationships (66%, n = 163), although approximately 20% to 30% of respondents did report such changes and 8% to 11% became non-sexual after castration. Respondents who were attracted to and fantasized about "only men" or who had sexual relationship with "only women" before castration were the least likely to report a change subsequent to castration. Respondents who were taking neither supplemental testosterone nor estrogen were more likely to report (i) becoming attracted to no one, (ii) fantasizing about no one, and (iii) becoming sexually inactive. Sexual changes in voluntarily castrated men vary and can be influenced by various factors including the use of supplemental testosterone or estrogen therapy. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Gender Preference in the Sexual Attractions, Fantasies, and Relationships of Voluntarily Castrated Men

PubMed Central

Handy, Ariel B.; Jackowich, Robyn A.; Wibowo, Erik; Johnson, Thomas Wayne; Wassersug, Richard J.

2016-01-01

Introduction Some men seek castration outside a clear medical need. This study explored how their sexuality changed after castration. Aim To explore changes in preferred gender(s) of sexual attraction, fantasy, and relationships in voluntarily castrated men with or without gonadal hormone therapy. Methods A questionnaire was posted at http://www.eunuch.org that yielded data on men who had been voluntarily castrated physically (n = 198) or chemically (n = 96). Main Outcome Measures Respondents were asked to report retrospectively on their sexuality, including their sexual activity and which gender(s) they were sexually attracted to, fantasized about, or had sexual relations with 6 months to 1 year before and after castration. Results A substantial proportion of men remained sexually active after castration; 37% had sex at least several times per week. Most respondents did not report a change in preferred gender(s) of attraction (65%, n = 181), fantasies (62%, n = 169), or sexual relationships (66%, n = 163), although approximately 20% to 30% of respondents did report such changes and 8% to 11% became non-sexual after castration. Respondents who were attracted to and fantasized about “only men” or who had sexual relationship with “only women” before castration were the least likely to report a change subsequent to castration. Respondents who were taking neither supplemental testosterone nor estrogen were more likely to report (i) becoming attracted to no one, (ii) fantasizing about no one, and (iii) becoming sexually inactive. Conclusion Sexual changes in voluntarily castrated men vary and can be influenced by various factors including the use of supplemental testosterone or estrogen therapy. PMID:26944778

Sexual Trajectories of Lesbian, Gay, and Bisexual Adults in the Netherlands.

PubMed

de Graaf, Hanneke; Picavet, Charles

2018-05-01

Studies on sexual trajectories of lesbian, gay, and bisexual (LGB) people generally focus on the first same-sex attraction and sexual experience, and their relation to self-identification and coming out as LGB. Relational and opposite-sex experiences are generally not taken into account. The aim of this study was to provide a more comprehensive overview of LGBs' sexual trajectories and to distinguish subsamples with different trajectories. A sample of same-sex attracted members of an online research panel (N = 3054) completed a sexual health questionnaire, including items about the timing of sexual and relational milestones. Results showed that the majority of gay men and lesbian women had same-sex sexual and relational experiences, whereas most bisexual men and women had had experiences with the opposite sex. Among gay men and lesbian women, two trajectories emerged, differing mainly on whether people had been sexually or romantically involved with opposite-sex partners, and on age of first same-sex attraction. Among those who were not exclusively attracted to the same sex, six patterns emerged, which differed especially with regard to the nature and comprehensiveness of their same-sex experiences. Within the exclusively same-sex attracted group, the trajectory with no heterosexual experiences related to higher levels of psychological adjustment. For non-exclusive sexually attracted people, trajectories including experience of same-sex relationships seem to be most beneficial. In conclusion, both relational and opposite-sex experiences proved to be important elements of LGB men and women's sexual trajectories.

Precopulatory sexual behavior of male mice is changed by the exposure to tannery effluent.

PubMed

Quintão, Thales Chagas; Rabelo, Letícia Martins; Alvarez, T G S; Guimarães, A T; Rodrigues, A S L; Cardoso, L S; Ferreira, R O; Malafaia, Guilherme

2018-03-01

Although the toxic potential of tannery effluents (TE) is acknowledged, the impacts these residues have on mammals who intake water contaminated with this pollutant are not completely known. Thus, in order to broaden the knowledge about how these contaminants affect the biota, the aim of the current study is to assess different behavioral categories (e.g.: sexual odor preference, opposite-sex attraction, and sexual discrimination) related to the sexual motivation and pre-copulation of male Swiss mice subjected to TE intake for 30 days, at concentrations 0.8% and 22%. The animals were subjected to locomotor performance evaluation through the Basso Mouse Scale (BMS), as well as to the open field (OF), odor preference (OPT), sexual orientation (SOT) and to scent marking tests (SMT) one week before the experiment ended. Our results evidenced that the treatments did not affect the animals' locomotor activity (in OF and BMS) or caused changes compatible to anxiogenic or anxiolytic behavior (in OF). However, mice exposed to TE (at both concentrations) presented discriminatory capacity deficit in the OPT test at the time to distinguish conspecific odors from the same sex, and from the opposite sex. They randomly explored (without preference) males and females, did not responded to stimuli in the SOT test, as well as did not appear capable of detecting female odor (in estrus phase) during the SMT. Thus, the current study was pioneer in evidencing that TE can influence the reproduction and the population dynamics of small rodents who intake water contaminated with the pollutant. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Sensory Bias Has Triggered the Evolution of Egg-Spots in Cichlid Fishes

PubMed Central

Theis, Anya; Salzburger, Walter

2011-01-01

Although, generally, the origin of sex-limited traits remains elusive, the sensory exploitation hypothesis provides an explanation for the evolution of male sexual signals. Anal fin egg-spots are such a male sexual signal and a key characteristic of the most species-rich group of cichlid fishes, the haplochromines. Males of about 1500 mouth-brooding species utilize these conspicuous egg-dummies during courtship – apparently to attract females and to maximize fertilization success. Here we test the hypothesis that the evolution of haplochromine egg-spots was triggered by a pre-existing bias for eggs or egg-like coloration. To this end, we performed mate-choice experiments in the basal haplochromine Pseudocrenilabrus multicolor, which manifests the plesiomorphic character-state of an egg-spot-less anal fin. Experiments using computer-animated photographs of males indeed revealed that females prefer images of males with virtual (‘in-silico’) egg-spots over images showing unaltered males. In addition, we tested for color preferences (outside a mating context) in a phylogenetically representative set of East African cichlids. We uncovered a strong preference for yellow, orange or reddish spots in all haplochromines tested and, importantly, also in most other species representing more basal lines. This pre-existing female sensory bias points towards high-quality (carotenoids-enriched) food suggesting that it is adaptive. PMID:22028784

Pheromonal Communication in the European House Dust Mite, Dermatophagoides pteronyssinus

PubMed Central

Steidle, Johannes L.M.; Barcari, Elena; Hradecky, Marc; Trefz, Simone; Tolasch, Till; Gantert, Cornelia; Schulz, Stefan

2014-01-01

Despite the sanitary importance of the European house dust mite Dermatophagoides pteronyssinus (Trouessart, 1897), the pheromonal communication in this species has not been sufficiently studied. Headspace analysis using solid phase micro extraction (SPME) revealed that nerol, neryl formate, pentadecane, (6Z,9Z)-6,9-heptadecadiene, and (Z)-8-heptadecene are released by both sexes whereas neryl propionate was released by males only. Tritonymphs did not produce any detectable volatiles. In olfactometer experiments, pentadecane and neryl propionate were attractive to both sexes as well as to tritonymphs. (Z)-8-heptadecene was only attractive to male mites. Therefore it is discussed that pentadecane and neryl propionate are aggregation pheromones and (Z)-8-heptadecene is a sexual pheromone of the European house dust mite D. pteronyssinus. To study the potential use of pheromones in dust mite control, long-range olfactometer experiments were conducted showing that mites can be attracted to neryl propionate over distances of at least 50 cm. This indicates that mite pheromones might be useable to monitor the presence or absence of mites in the context of control strategies. PMID:26462831

Population Structure, Movement Patterns, and Frequency of Multiple Matings in Tenodera sinensis (Mantodea: Mantidae).

PubMed

Christensen, Tyler; Brown, William D

2018-04-14

Models of the evolution of sexual cannibalism show that the frequency of male mating opportunities has significant impact on male choice and male risk aversion. In this study, we examined ecological components that should affect opportunities for multiple mating in wild populations of the Chinese mantid (Tenodera sinensis Saussure). While conducting mark-recapture studies of two field populations over the course of two seasons, along with Global Positioning System data on locations of individuals, we collected data on population densities, movement patterns, and individual ranges to estimate the overlap of adult males and female mantids. Our results show that local populations of mantids range from 89 to 161 individuals and occur at densities ranging from 10 to 39 mantids per 1,000 m2. Males move greater distances daily compared with females, giving males larger home range sizes. The ranges of male mantids overlapped with multiple females, thus offering the potential for multiple mating by males. We directly observed 11 encounters between male and female T. sinensis, including one multiple mating by an individual male. The overall mate encounter rate for males was 12.5%. We also provide additional observations of interspecific sexual attraction between T. sinensis and Mantis religiosa Linne (Mantodea: Mantidae). Mantids were most commonly found within the top 20% of two flowering plants, goldenrod (Solidago Linnaeus spp. (Asterales: Asteraceae)) and mugwort (Artemisia vulgaris Linnaeus (Asterales: Asteraceae)), which should place them in prime locations for capturing flying pollinators.

Characteristic odor of Osmoderma eremita identified as a male-released pheromone.

PubMed

Larsson, Mattias C; Hedin, Jonas; Svensson, Glenn P; Tolasch, Till; Francke, Wittko

2003-03-01

Osmoderma eremita (Scopoli) is an endangered scarab beetle living in hollow trees. It has mainly been known for its characteristic odor, typically described as a fruity, peachlike or plumlike aroma. The odor emanating from a single beetle can sometimes be perceived from a distance of several meters. In this paper, we show that the characteristic odor from O. eremita is caused by the compound (R)-(+)-gamma-decalactone, released in large quantities mainly or exclusively by male beetles. Antennae from male and female beetles responded in a similar way to (R)-(+)-gamma-decalactone in electroantennographic recordings. Field trapping experiments showed that (R)-(+)-gamma-decalactone is a pheromone attracting female beetles. Lactones similar to (R)-(+)-gamma-decalactone are frequently used as female-released sex pheromones by phytophagous scarabs. This is, however, the first evidence of a lactone used as a male-produced pheromone in scarab beetles. We propose that the strong signal from males is a sexually selected trait used to compete for females and matings. The signal could work within trees but also act as a guide to tree hollows, which are an essential resource for O. eremita. Males may, thus, attract females dispersing from their natal tree by advertising a suitable habitat. This signal could also be exploited by other males searching for tree hollows or for females, which would explain the catch of several males in our traps.

Perineal swelling, intermenstrual cycle, and female sexual behavior in bonobos (Pan paniscus).

PubMed

Paoli, T; Palagi, E; Tacconi, G; Tarli, S Borgognini

2006-04-01

Many reports have claimed that the duration of the swelling cycle in female bonobos (Pan paniscus) is longer than that of chimpanzees, and that the bonobo maximum swelling phase is markedly prolonged. Field data on intermenstrual intervals (IMIs) in female bonobos are limited and restricted to interswelling intervals (ISIs), which are assumed to reflect the IMI, though a direct comparison between the duration of ISIs and IMIs is still lacking. Reports on bonobo sexual activity as a function of the swelling phase are often contradictory. Moreover, the function of female homosexual interactions (genito-genital (GG) rubbing) is still debated. This study examines the reliability of the ISI as an approximation of the IMI, and the attractivity of female sexual swellings for other individuals. An analysis of 51 ISI-IMI pairs showed that ISIs are a fair representation of the reproductive cycle. The cycle length was 35.6+/-1.1 SE days relying on the ISI, whereas it was 35.0+/-1.1 SE days considering the IMI. This result is similar to the cycle length reported for chimpanzees. Female homosexual interactions and copulatory rates were higher during maximum tumescence, suggesting that the sexual swelling may be attractive for both males and other females. Furthermore, the GG-rubbing was performed free of a hierarchical postural imposition, and was not correlated with affinitive interactions. We suggest that GG-rubbing, which is generally the most frequent female sexual interaction, is a tool for social assessments among females. Copyright (c) 2006 Wiley-Liss, Inc.

Mental health inequalities among gay and bisexual men in England, Scotland and Wales: a large community-based cross-sectional survey.

PubMed

Hickson, Ford; Davey, Calum; Reid, David; Weatherburn, Peter; Bourne, Adam

2017-06-01

Sexual minorities suffer worse mental health than the sexual majority but little is known about differences in mental health within sexual minorities. We aimed to describe inequality in mental health indicators among gay and bisexual men. Using multi-channel community-based opportunistic sampling we recruited 5799 eligible men aged 16 years and over, living in England, Scotland and Wales and who were sexually attracted to other men, to a self-completion Internet health survey. Mental health indicators (depression (PHQ-9), anxiety (GAD-7), suicide attempt and self-harm) were examined for independent associations across common axes of inequality (age, ethnicity, migrancy, education, income, cohabitation and living in London). Mental ill-health was common: 21.3% were depressed and 17.1% anxious, while 3.0% had experienced attempted suicide and 6.5% had self-harmed within the last 12 months. All four indicators were associated with younger age, lower education and lower income. Depression was also associated with being a member of visible ethnic minorities and sexual attraction to women as well as men. Cohabiting with a male partner and living in London were protective of mental health. Community interventions to increase mental health among gay and bisexual men should be designed to disproportionately benefit younger men and those living on lower incomes. © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Condition-dependent pheromone signaling by male rock lizards: more oily scents are more attractive.

PubMed

Martín, José; López, Pilar

2010-05-01

Pheromones of vertebrates are often a mixture of several chemicals with different properties and messages, and their production seems condition dependent. Thus, pheromones are a good, but little studied, example of multiple sexual signals. Femoral gland secretions of male rock lizards Iberolacerta cyreni contain steroids that may act as pheromones, but there are also many other lipids, such as oleic acid, whose allocation to secretions may be costly because it has to be diverted from body fat reserves. This suggests that oleic acid could also have some function in secretions. Chemical analyses showed that proportions of oleic acid in femoral secretions of males were positively related to body condition of males, suggesting that the oleic acid secreted may reflect the amount of body fat reserves of a male. Tongue-flick bioassays showed that females were able to detect by chemosensory cues alone differences in proportions of oleic acid in secretions of males. Scents of males with more oleic acid elicited stronger chemosensory responses by females. Further tests with chemical standards confirmed that females distinguished oleic acid, and changes in its concentration, from other chemicals that are naturally found in secretions of males. Moreover, choice trials of scent-marked substrates showed that females were more attracted to areas that were experimentally manipulated to increase the proportion of oleic acid in natural scent marks of males. We suggest that oleic acid in femoral secretions might be a reliable advertisement of a male's body condition, which females could use to select high-quality mates in conjunction with information provided by other chemicals. Alternatively, scent marks with more oleic acid might be simply more attractive to females if chemosensory responses of females to scent of males were originated by a preexisting sensory bias for food chemicals such as the oleic acid. Nevertheless, this sensory trap might have evolved into an honest signal because the elaboration of the signal seems differentially costly for males with different body conditions.

Understanding sexual orientation and health in Canada: Who are we capturing and who are we missing using the Statistics Canada sexual orientation question?

PubMed

Dharma, Christoffer; Bauer, Greta R

2017-04-20

Public health research on inequalities in Canada depends heavily on population data sets such as the Canadian Community Health Survey. While sexual orientation has three dimensions - identity, behaviour and attraction - Statistics Canada and public health agencies assess sexual orientation with a single questionnaire item on identity, defined behaviourally. This study aims to evaluate this item, to allow for clearer interpretation of sexual orientation frequencies and inequalities. Through an online convenience sampling of Canadians ≥14 years of age, participants (n = 311) completed the Statistics Canada question and a second set of sexual orientation questions. The single-item question had an 85.8% sensitivity in capturing sexual minorities, broadly defined by their sexual identity, lifetime behaviour and attraction. Kappa statistic for agreement between the single item and sexual identity was 0.89; with past year, lifetime behaviour and attraction were 0.39, 0.48 and 0.57 respectively. The item captured 99.3% of those with a sexual minority identity, 84.2% of those with any lifetime same-sex partners, 98.4% with a past-year same-sex partner, and 97.8% who indicated at least equal attraction to same-sex persons. Findings from Statistics Canada surveys can be best interpreted as applying to those who identify as sexual minorities. Analyses using this measure will underidentify those with same-sex partners or attractions who do not identify as a sexual minority, and should be interpreted accordingly. To understand patterns of sexual minority health in Canada, there is a need to incorporate other dimensions of sexual orientation.

The Curse of Curves: Sex Differences in the Associations Between Body Shape and Pain Expression.

PubMed

Vigil, Jacob M; Strenth, Chance R; Mueller, Andrea A; DiDomenico, Jared; Beltran, Diego Guevara; Coulombe, Patrick; Smith, Jane Ellen

2015-06-01

This study examines the associations between objective and subjective measurements and impressions of body shape and cold pressor pain reporting in healthy adults. On the basis of sexual selection theory (SST), we hypothesized that body characteristics that are universally preferred by the opposite sex-specifically, lower waist-to-hip ratios (WHR) in women and higher shoulder-to-hip ratios (SHR) in men-and characteristics (e.g., proportion of body fat in women) that infer attractiveness differently across cultures will correspond to higher experimental pain reporting in women and lower pain reporting in males. A convenience sample of young adults (n = 96, 58 females, 18-24 years; mean age = 19.4) was measured for body mass index (BMI), WHR, SHR, and subjective body impressions (SBI), along with cold pressor pain reporting. The findings showed that BMI was positively associated with WHR and less-positive SBI in both sexes. Consistent with SST, however, only BMI and WHR predicted variability in pain expression in women, whereas only SHR predicted variability in men. Subjective body impressions were positively associated with SHR among males and unrelated to WHR among females, yet only females showed a positive association between SBI and higher pain reporting. The findings suggest that sexually selected physical characteristics (WHR and SHR) and culturally influenced somatic (BMI) and psychological (SBI) indicators of attractiveness correspond with variability in pain reporting, potentially reflecting the general tendency for people to express clusters of sexually selected and culturally influenced traits that may include differential pain perception.

In Search of Emerging Same-Sex Sexuality: Romantic Attractions at Age 13 Years.

PubMed

Li, Gu; Hines, Melissa

2016-10-01

Sex-typed behavior in childhood is significantly related to sexual orientation in adulthood. In addition, same-sex attractions in early adolescence are more non-exclusive than in adulthood and can differ from later same-sex orientations. However, little research has focused on romantic attractions as they emerge during early adolescence. Drawing a sample from the Avon Longitudinal Study of Parents and Children (197 girls, 204 boys), the current study examined whether same-sex romantic attractions at age 13 years were exclusive, and whether they were predicted by sex-typed behavior at age 3.5 years. No young adolescents in this sample reported exclusive same-sex attractions, and increased same-sex attractions were not significantly related to reduced other-sex sexualities. Childhood sex-typed behavior did not significantly predict early same-sex attractions, suggesting that early same-sex attractions differ from later same-sex orientations. The current study highlights the importance of studying the development of sexuality beginning prior to adulthood.

When sex doesn't sell: using sexualized images of women reduces support for ethical campaigns.

PubMed

Bongiorno, Renata; Bain, Paul G; Haslam, Nick

2013-01-01

Images of scantily clad women are used by advertisers to make products more attractive to men. This "sex sells" approach is increasingly employed to promote ethical causes, most prominently by the animal-rights organization PETA. Yet sexualized images can dehumanize women, leaving an unresolved paradox--is it effective to advertise an ethical cause using unethical means? In Study 1, a sample of Australian male undergraduates (N = 82) viewed PETA advertisements containing either sexualized or non-sexualized images of women. Intentions to support the ethical organization were reduced for those exposed to the sexualized advertising, and this was explained by their dehumanization of the sexualized women, and not by increased arousal. Study 2 used a mixed-gender community sample from the United States (N = 280), replicating this finding and extending it by showing that behaviors helpful to the ethical cause diminished after viewing the sexualized advertisements, which was again mediated by the dehumanization of the women depicted. Alternative explanations relating to the reduced credibility of the sexualized women and their objectification were not supported. When promoting ethical causes, organizations may benefit from using advertising strategies that do not dehumanize women.

When Sex Doesn't Sell: Using Sexualized Images of Women Reduces Support for Ethical Campaigns

PubMed Central

Bongiorno, Renata; Bain, Paul G.; Haslam, Nick

2013-01-01

Images of scantily clad women are used by advertisers to make products more attractive to men. This “sex sells” approach is increasingly employed to promote ethical causes, most prominently by the animal-rights organization PETA. Yet sexualized images can dehumanize women, leaving an unresolved paradox – is it effective to advertise an ethical cause using unethical means? In Study 1, a sample of Australian male undergraduates (N = 82) viewed PETA advertisements containing either sexualized or non-sexualized images of women. Intentions to support the ethical organization were reduced for those exposed to the sexualized advertising, and this was explained by their dehumanization of the sexualized women, and not by increased arousal. Study 2 used a mixed-gender community sample from the United States (N = 280), replicating this finding and extending it by showing that behaviors helpful to the ethical cause diminished after viewing the sexualized advertisements, which was again mediated by the dehumanization of the women depicted. Alternative explanations relating to the reduced credibility of the sexualized women and their objectification were not supported. When promoting ethical causes, organizations may benefit from using advertising strategies that do not dehumanize women. PMID:24367591

Dynamics of sperm transfer in the ant Leptothorax gredleri

NASA Astrophysics Data System (ADS)

Oppelt, Angelika; Heinze, Jürgen

2007-09-01

Mating tactics differ remarkably between and within species of social Hymenoptera (bees, wasps, ants) concerning, e.g., mating frequencies, sperm competition, and the degree of male sperm limitation. Although social Hymenoptera might, therefore, potentially be ideal model systems for testing sexual selection theory, the dynamics of mating and sperm transfer have rarely been studied in species other than social bees, and basic information needed to draw conclusions about possible sperm competition and female choice is lacking. We investigated sperm transfer in the ant Leptothorax gredleri, a species in which female sexuals attract males by “female calling.” The analysis of 38 female sexuals fixed immediately or up to 7 days after copulation with a single male each revealed that the sperm is transferred into the female bursa copulatrix embedded in a gelatinous mass, presumably a spermatophore. Sperm cells rapidly start to migrate from the tip of the spermatophore towards the spermatheca, but transfer is drastically slowed down by an extreme constriction of the spermathecal duct, through which sperm cells have to pass virtually one by one. This results in the spermatheca being filled only between one and several hours after mating. During this time, the posterior part of the spermatophore seals the junction between bursa copulatrix and spermathecal duct and prevents sperm loss. The prolonged duration of sperm transfer might allow female sexuals to chose between ejaculates and explain previously reported patterns of single paternity of the offspring of multiply mated queens.

Educational Attainment by Life Course Sexual Attraction: Prevalence and Correlates in a Nationally Representative Sample of Young Adults

PubMed Central

Walsemann, Katrina M.; Lindley, Lisa L.; Gentile, Danielle; Welihindha, Shehan V.

2014-01-01

Researchers know relatively little about the educational attainment of sexual minorities, despite the fact that educational attainment is consistently associated with a range of social, economic, and health outcomes. We examined whether sexual attraction in adolescence and early adulthood was associated with educational attainment in early adulthood among a nationally representative sample of US young adults. We analyzed Waves I and IV restricted data from the National Longitudinal Study of Adolescent Health (n=14,111). Sexual orientation was assessed using self-reports of romantic attraction in Waves I (adolescence) and IV (adulthood). Multinomial regression models were estimated and all analyses were stratified by gender. Women attracted to the same-sex in adulthood only had lower educational attainment compared to women attracted only to the opposite-sex in adolescence and adulthood. Men attracted to the same-sex in adolescence only had lower educational attainment compared to men attracted only to the opposite-sex in adolescence and adulthood. Adolescent experiences and academic performance attenuated educational disparities among men and women. Adjustment for adolescent experiences also revealed a suppression effect; women attracted to the same-sex in adolescence and adulthood had lower predicted probabilities of having a high school diploma or less compared to women attracted only to the opposite-sex in adolescence and adulthood. Our findings challenge previous research documenting higher educational attainment among sexual minorities in the US. Additional population-based studies documenting the educational attainment of sexual minority adults are needed. PMID:25382888

Psychiatric symptoms and same-sex sexual attraction and behavior in light of childhood gender atypical behavior and parental relationships.

PubMed

Alanko, Katarina; Santtila, Pekka; Witting, Katarina; Varjonen, Markus; Jern, Patrik; Johansson, Ada; von der Pahlen, Bettina; Kenneth Sandnabba, N

2009-01-01

This study explores the relation between the level of current symptoms of depression and anxiety and recalled childhood gender atypical behavior (GAB), and quality of relationships with parents among men and women who reported same-sex sexual attraction or engaged in same-sex sexual behavior and men and women who did not. Matched pairs, 79 men (n = 158) and 148 women (n = 296), with equal levels of GAB were created of Finnish participants with either same-sex sexual attraction or behavior and participants without. The measures used were retrospective questionnaires. Ratings of maternal and paternal over-control and coldness differed as a function of same-sex sexual attraction or behavior. Childhood GAB was correlated with negative ratings of parental relationships. Both same-sex sexual attraction or behavior and a history of childhood GAB affected the reported levels of current depression and anxiety. Only gender typical participants with no same-sex sexual attraction or behavior reported significantly lower levels of symptoms. The findings suggest that childhood GAB is related to later distress both among hetero- and homosexual individuals. The elevated level of psychological distress among homosexual individuals, reported in several studies, might--to some extent--be caused by their generally higher levels of childhood GAB as opposed to a homosexual orientation per se.

The Geography of Sexual Orientation: Structural Stigma and Sexual Attraction, Behavior, and Identity Among Men Who Have Sex with Men Across 38 European Countries.

PubMed

Pachankis, John E; Hatzenbuehler, Mark L; Mirandola, Massimo; Weatherburn, Peter; Berg, Rigmor C; Marcus, Ulrich; Schmidt, Axel J

2017-07-01

While the prevalence of sexual identities and behaviors of men who have sex with men (MSM) varies across countries, no study has examined country-level structural stigma toward sexual minorities as a correlate of this variation. Drawing on emerging support for the context-dependent nature of MSM's open sexual self-identification cross-nationally, we examined country-level structural stigma as a key correlate of the geographic variation in MSM's sexual attraction, behavior, and identity, and concordance across these factors. Data come from the European MSM Internet Survey, a multi-national dataset containing a multi-component assessment of sexual orientation administered across 38 European countries (N = 174,209). Country-level stigma was assessed using a combination of national laws and policies affecting sexual minorities and a measure of attitudes toward sexual minorities held by the citizens of each country. Results demonstrate that in more stigmatizing countries, MSM were significantly more likely to report bisexual/heterosexual attractions, behaviors, and identities, and significantly less likely to report concordance across these factors, than in less stigmatizing countries. Settlement size moderated associations between country-level structural stigma and odds of bisexual/heterosexual attraction and behavior, such that MSM living in sparsely populated locales within high-structural stigma countries were the most likely to report bisexual or heterosexual behaviors and attractions. While previous research has demonstrated associations between structural stigma and adverse physical and mental health outcomes among sexual minorities, this study was the first to show that structural stigma was also a key correlate not only of sexual orientation identification, but also of MSM's sexual behavior and even attraction. Findings have implications for understanding the ontology of MSM's sexuality and suggest that a comprehensive picture of MSM's sexuality will come from attending to the local contexts surrounding this important segment of the global population.

Phylogenetic distribution of a male pheromone that may exploit a nonsexual preference in lampreys

USGS Publications Warehouse

Buchinger, Tyler J.; Bussy, Ugo; Li, Ke; Wang, Huiyong; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas

2017-01-01

Pheromones are among the most important sexual signals used by organisms throughout the animal kingdom. However, few are identified in vertebrates, leaving the evolutionary mechanisms underlying vertebrate pheromones poorly understood. Pre-existing biases in receivers’ perceptual systems shape visual and auditory signaling systems, but studies on how receiver biases influence the evolution of pheromone communication remain sparse. The lamprey Petromyzon marinus uses a relatively well-understood suite of pheromones and offers a unique opportunity to study the evolution of vertebrate pheromone communication. Previous studies indicate that male signaling with the mating pheromone 3-keto petromyzonol sulfate (3kPZS) may exploit a nonsexual attraction to juvenile-released 3kPZS that guides migration into productive rearing habitat. Here, we infer the distribution of male signaling with 3kPZS using a phylogenetic comparison comprising six of ten genera and two of three families. Our results indicate that only P. marinus and Ichthyomyzon castaneus release 3kPZS at high rates. Olfactory and behavioral assays with P. marinus, I. castaneus and a subset of three other species that do not use 3kPZS as a sexual signal indicate that male signaling might drive the evolution of female adaptations to detect 3kPZS with specific olfactory mechanisms and respond to 3kPZS with targeted attraction relevant during mate search. We postulate that 3kPZS communication evolved independently in I. castaneus and P. marinus, but cannot eliminate the alternative that other species lost 3kPZS communication. Regardless, our results represent a rare macroevolutionary investigation of a vertebrate pheromone and insight into the evolutionary mechanisms underlying pheromone communication.

Presence of Putative Male-Produced Sex Pheromone in Lutzomyia cruciata (Diptera: Psychodidae), Vector of Leishmania mexicana.

PubMed

Serrano, A K; Rojas, J C; Cruz-López, L C; Malo, Edi A; Mikery, O F; Castillo, A

2016-11-01

Lutzomyia cruciata (Coquillet) is a vector of cutaneous leishmaniasis in Mexico and Central America. However, several aspects of its ecology and behavior are unknown, including whether a male pheromone partially mediates the sexual behavior of this sand fly. In this study, we evaluated the behavioral response of females to male abdominal extracts in a Y-tube olfactometer. The volatile compounds from male abdominal extracts were identified by gas chromatography-mass spectrometry and compared with those of female abdominal extracts. Finally, the disseminating structures of the putative sex pheromone were examined by scanning electron microscopy in the male abdomen. Females were more attracted to male abdominal extract than to the hexane control, suggesting the presence of male-produced sex pheromone. The male abdominal extracts were characterized by the presence of 12 sesquiterpene compounds. The major component, an unknown sesquiterpene with an abundance of 60%, had a mass spectrum with molecular ion of m/z 262. In contrast, the abdominal female extracts contained saturated fatty acids. Finally, we detected the presence of small "papules" with a mammiform morphology distributed on the abdominal surface of tergites IV-VII of male Lu. cruciata These structures are not present in females. We conclude that Lu. cruciata males likely produce a pheromone involved in attracting or courting females. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

From disease to desire, pleasure to the pill: A qualitative study of adolescent learning about sexual health and sexuality in Chile.

PubMed

Macintyre, Anna K-J; Montero Vega, Adela Rosa; Sagbakken, Mette

2015-09-23

Sexual and reproductive rights include access to accurate and appropriate information in order to make informed decisions. In the current age of media globalization and Internet, adolescents are exposed to information about sexual health and sexuality from a myriad of sources. The objective of this study was to explore sources of information and adolescent learning about sexual health and sexuality in Santiago, Chile. Data collection included four focus group discussions with a total of 24 adolescents 18-19 years old, 20 semi-structured interviews with adolescents 16-19 years old, and seven interviews with key informants working with adolescents. Audio recordings were transcribed verbatim and analysed using content analysis. The primary sources of sexual health and sexuality information were parents, teachers and friends, whilst secondary sources included health professionals for females and Internet for males. Information provided by the trusted sources of parents, teachers and health professionals tended to focus on biological aspects of sexuality, particularly pregnancy and sexually transmitted infections. Limited emphasis was placed on topics such as love, attraction, pleasure, relationships, abstinence and sexual violence. Information focused primarily on heterosexual relations and reproduction. Adolescents learnt about relationships and sexual acts through friends, partners and, for many males, pornography. Findings indicate a lack of available information on partner communication, setting personal limits, and contraception, including morally neutral and medically correct information about emergency contraception. This study highlights numerous gaps between adolescent information needs and information provided by parents, teachers and health professionals. The priority these trusted sources place on providing biological information overshadows learning about emotional and relational aspects of sexuality. This biological rationalization of adolescent sexual behaviour neglects the way gender inequality, peer-pressure, coercion, media eroticization and religion influence adolescent sexual decision-making. The heteronormativity of information excludes other sexual orientations and disregards the diverse spectrum of human sexual behaviours. Finally, the limited provision of practical information hinders development of skills necessary for ensuring safe, consensual and pleasurable sexual relations. Trusted adults are encouraged to engage adolescents in critical reflection on a broad range of sexuality topics, dispelling myths, and building knowledge and skills necessary to make informed decisions.

The Role of Breast Size and Areolar Pigmentation in Perceptions of Women's Sexual Attractiveness, Reproductive Health, Sexual Maturity, Maternal Nurturing Abilities, and Age.

PubMed

Dixson, Barnaby J; Duncan, Melanie; Dixson, Alan F

2015-08-01

Women's breast morphology is thought to have evolved via sexual selection as a signal of maturity, health, and fecundity. While research demonstrates that breast morphology is important in men's judgments of women's attractiveness, it remains to be determined how perceptions might differ when considering a larger suite of mate relevant attributes. Here, we tested how variation in breast size and areolar pigmentation affected perceptions of women's sexual attractiveness, reproductive health, sexual maturity, maternal nurturing abilities, and age. Participants (100 men; 100 women) rated images of female torsos modeled to vary in breast size (very small, small, medium, and large) and areolar pigmentation (light, medium, and dark) for each of the five attributes listed above. Sexual attractiveness ratings increased linearly with breast size, but large breasts were not judged to be significantly more attractive than medium-sized breasts. Small and medium-sized breasts were rated as most attractive if they included light or medium colored areolae, whereas large breasts were more attractive if they had medium or dark areolae. Ratings for perceived age, sexual maturity, and nurturing ability also increased with breast size. Darkening the areolae reduced ratings of the reproductive health of medium and small breasts, whereas it increased ratings for large breasts. There were no significant sex differences in ratings of any of the perceptual measures. These results demonstrate that breast size and areolar pigmentation interact to determine ratings for a suite of sociosexual attributes, each of which may be relevant to mate choice in men and intra-sexual competition in women.

Sex-dependent selection differentially shapes genetic variation on and off the guppy Y chromosome.

PubMed

Postma, Erik; Spyrou, Nicolle; Rollins, Lee Ann; Brooks, Robert C

2011-08-01

Because selection is often sex-dependent, alleles can have positive effects on fitness in one sex and negative effects in the other, resulting in intralocus sexual conflict. Evolutionary theory predicts that intralocus sexual conflict can drive the evolution of sex limitation, sex-linkage, and sex chromosome differentiation. However, evidence that sex-dependent selection results in sex-linkage is limited. Here, we formally partition the contribution of Y-linked and non-Y-linked quantitative genetic variation in coloration, tail, and body size of male guppies (Poecilia reticulata)-traits previously implicated as sexually antagonistic. We show that these traits are strongly genetically correlated, both on and off the Y chromosome, but that these correlations differ in sign and magnitude between both parts of the genome. As predicted, variation in attractiveness was found to be associated with the Y-linked, rather than with the non-Y-linked component of genetic variation in male ornamentation. These findings show how the evolution of Y-linkage may be able to resolve sexual conflict. More generally, they provide unique insight into how sex-specific selection has the potential to differentially shape the genetic architecture of fitness traits across different parts of the genome. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Sexual Attraction and Religious Therapists: Survey Findings and Implications.

ERIC Educational Resources Information Center

Case, Paul W.; McMinn, Mark R.; Meek, Katheryn Rhoads

1997-01-01

Christian therapists were surveyed concerning beliefs and behaviors regarding sexual attraction and sexual expression toward their clients (N=500). Responses are compared with those from a similar survey of 456 psychologists selected without regard to religious values. Religious factors that may increase the stigma of admitting sexual attraction…

Facial Attractiveness Ratings from Video-Clips and Static Images Tell the Same Story

PubMed Central

Rhodes, Gillian; Lie, Hanne C.; Thevaraja, Nishta; Taylor, Libby; Iredell, Natasha; Curran, Christine; Tan, Shi Qin Claire; Carnemolla, Pia; Simmons, Leigh W.

2011-01-01

Most of what we know about what makes a face attractive and why we have the preferences we do is based on attractiveness ratings of static images of faces, usually photographs. However, several reports that such ratings fail to correlate significantly with ratings made to dynamic video clips, which provide richer samples of appearance, challenge the validity of this literature. Here, we tested the validity of attractiveness ratings made to static images, using a substantial sample of male faces. We found that these ratings agreed very strongly with ratings made to videos of these men, despite the presence of much more information in the videos (multiple views, neutral and smiling expressions and speech-related movements). Not surprisingly, given this high agreement, the components of video-attractiveness were also very similar to those reported previously for static-attractiveness. Specifically, averageness, symmetry and masculinity were all significant components of attractiveness rated from videos. Finally, regression analyses yielded very similar effects of attractiveness on success in obtaining sexual partners, whether attractiveness was rated from videos or static images. These results validate the widespread use of attractiveness ratings made to static images in evolutionary and social psychological research. We speculate that this validity may stem from our tendency to make rapid and robust judgements of attractiveness. PMID:22096491

Cross-generational effects of sexual harassment on female fitness in the guppy.

PubMed

Gasparini, Clelia; Devigili, Alessandro; Pilastro, Andrea

2012-02-01

Sexual harassment is a common outcome of sexual conflict over mating rate. A large number of studies have identified several direct costs to females of sexual harassment including energy expenditure and reduced foraging ability. However, the fitness consequences of sexual harassment for descendants have rarely been investigated. Here, we manipulated the level of sexual harassment and mating rate in two groups of female guppies, Poecilia reticulata, a live-bearing fish in which sexual conflict over mating rate is particularly pronounced. Each female was allowed to interact with three males for one day (low sexual harassment, LSH) or for eight days (high sexual harassment, HSH) during each breeding cycle throughout their life. Female lifetime fecundity did not differ between the groups, but we found a strong effect on offspring fitness. HSH females produced (1) daughters with smaller bodies and (2) sons with shorter gonopodia, which were less attractive to females and less successful in coercive matings than their LSH counterparts. Although these results may be influenced by the indirect effects of sex ratio differences between treatments, they suggest that sexual harassment and elevated mating rate can have negative cross-generational fitness effects and more profound evolutionary consequences than currently thought. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Chemical sexualities: the use of pharmaceutical and cosmetic products by youth in South Sulawesi, Indonesia.

PubMed

Hardon, Anita; Idrus, Nurul Ilmi; Hymans, Takeo David

2013-05-01

Although young people in their everyday lives consume a bewildering array of pharmaceutical, dietary and cosmetic products to self-manage their bodies, moods and sexuality, these practices are generally overlooked by sexual and reproductive health programmes. Nevertheless, this self-management can involve significant (sexual) health risks. This article draws from the initial findings of the University of Amsterdam's ChemicalYouth project. Based on interviews with 142 youths, focus group discussions and participant observation in South Sulawesi, Indonesia, we found that young people - in the domain of sexual health - turn to pharmaceuticals and cosmetics to: (1) feel clean and attractive; (2) increase (sexual) stamina; (3) feel good and sexually confident; (4) counter sexual risks; and (5) for a group of transgender youths, to feminize their male bodies. How youth achieve these desires varies depending on their income and the demands of their working lives. Interestingly, the use of pharmaceuticals and cosmetics was less gendered than expected. Sexual health programmes need to widen their definitions of risk, cooperate with harm reduction programmes to provide youth with accurate information, and tailor themselves to the diverse sexual health concerns of their target groups. Copyright © 2013 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

Patterns of Alcohol Use and Consequences Among Empirically Derived Sexual Minority Subgroups

PubMed Central

Talley, Amelia E.; Sher, Kenneth J.; Steinley, Douglas; Wood, Phillip K.; Littlefield, Andrew K.

2012-01-01

Objective: The current study develops an empirically determined classification of sexual orientation developmental patterns based on participants’ annual reports of self-identifications, sexual attractions, and sexual behaviors during the first 4 years of college. A secondary aim of the current work was to examine trajectories of alcohol involvement among identified subgroups. Method: Data were drawn from a subsample of a longitudinal study of incoming first-time college students at a large, public university (n = 2,068). Longitudinal latent class analysis was used to classify sexual minority participants into empirically derived subgroups based on three self-reported facets of sexual orientation. Multivariate repeated-measures analyses were conducted to examine how trajectories of alcohol involvement varied by sexual orientation class membership. Results: Four unique subclasses of sexual orientation developmental patterns were identified for males and females: one consistently exclusively heterosexual group and three sexual minority groups. Despite generally similar alcohol use patterns among subclasses, certain sexual minority subgroups reported elevated levels of alcohol-related negative consequences and maladaptive motivations for use throughout college compared with their exclusively heterosexual counterparts. Conclusions: Elevations in coping and conformity motivations for alcohol use were seen among those subgroups that also evidenced heightened negative alcohol-related consequences. Implications and limitations of the current work are discussed. PMID:22333337

Visual effects in great bowerbird sexual displays and their implications for signal design.

PubMed

Endler, John A; Gaburro, Julie; Kelley, Laura A

2014-05-22

It is often assumed that the primary purpose of a male's sexual display is to provide information about quality, or to strongly stimulate prospective mates, but other functions of courtship displays have been relatively neglected. Male great bowerbirds (Ptilonorhynchus nuchalis) construct bowers that exploit the female's predictable field of view (FOV) during courtship displays by creating forced perspective illusions, and the quality of illusion is a good predictor of mating success. Here, we present and discuss two additional components of male courtship displays that use the female's predetermined viewpoint: (i) the rapid and diverse flashing of coloured objects within her FOV and (ii) chromatic adaptation of the female's eyes that alters her perception of the colour of the displayed objects. Neither is directly related to mating success, but both are likely to increase signal efficacy, and may also be associated with attracting and holding the female's attention. Signal efficacy is constrained by trade-offs between the signal components; there are both positive and negative interactions within multicomponent signals. Important signal components may have a threshold effect on fitness rather than the often assumed linear relationship.

Is it possible to define the ideal lips?

PubMed

Kar, M; Muluk, N B; Bafaqeeh, S A; Cingi, C

2018-02-01

The lips are an essential component of the symmetry and aesthetics of the face. Cosmetic surgery to modify the lips has recently gained in popularity, but the results are in some cases disasterous. In this review, we describe the features of the ideal lips for an individual's face. The features of the ideal lips with respect to facial anatomy, important anatomical landmarks of the face, the facial proportions of the lips and ethnic and sexual differences are described. The projection and relative sizes of the upper and lower lips are as significant to lip aesthetics as the proportion of the lips to the rest of the facial structure. Robust, pouty lips are considered to be sexually attractive by both males and females. Horizontal thirds and the golden ratio describe the proportions that contribute to the beauty and attractiveness of the lips. In young Caucasians, the ideal ratio of the vertical height of the upper lip to that of the lower lip is 1:1.6. Blacks, genetically, have a greater lip volume. The shape and volume of a person's lips are of great importance in the perception of beauty by humans. The appearance of the lips in part determines the attractiveness of a person's face. In females, fuller lips in relation to facial width as well as greater vermilion height are considered to be attractive. Copyright © 2018 Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

Field Crickets Compensate for Unattractive Static Long-Distance Call Components by Increasing Dynamic Signalling Effort.

PubMed

McAuley, Emily M; Bertram, Susan M

2016-01-01

The evolution of multiple sexual signals presents a dilemma since individuals selecting a mate should pay attention to the most honest signal and ignore the rest; however, multiple signals may evolve if, together, they provide more information to the receiver than either one would alone. Static and dynamic signals, for instance, can act as multiple messages, providing information on different aspects of signaller quality that reflect condition at different time scales. While the nature of static signals makes them difficult or impossible for individuals to augment, dynamic signals are much more susceptible to temporary fluctuations in effort. We investigated whether male Texas field crickets, Gryllus texensis, that produce unattractive static signals compensate by dynamically increasing their calling effort. Our findings lend partial support to the compensation hypothesis, as males that called at unattractive carrier frequencies (a static trait) spent more time calling each night (a dynamic trait). Interestingly, this finding was most pronounced in males that called with attractive pulse characteristics (static traits) but did not occur in males that called with unattractive pulse characteristics. Males that signalled with unattractive pulse characteristics (duration and pause) spent less time calling through the night. Our correlative findings on wild caught males suggest that only males that signal with attractive pulse characteristics may be able to afford to pay the costs of both trait exaggeration and increased calling effort to compensate for poor carrier frequencies.

Sexual Preference Similarity, Attitude Similarity, and Perceived Counselor Credibility and Attractiveness.

ERIC Educational Resources Information Center

Atkinson, Donald R.; And Others

1981-01-01

Examined the effect of membership group and attitudinal similarity on perceived counselor credibility and attractiveness. Homosexual men (N=84) rated the counselor's credibility and attractiveness after listening to a recorded counseling interview. The counselor was rated more expert, trustworthy, and attractive when he stated a sexual preference…

Behavioural development of conspecific odour preferences in bank voles, Clethrionomys glareolus.

PubMed

Kruczek, Malgorzata; Golas, Aniela

2003-08-29

Biological odours of conspecifics are known to have strong influences on behavioural interaction in bank voles Clethrionomys glareolus. This experiment tested two hypotheses. (1) Olfactory cues from familiar and unfamiliar mature opposite-sex conspecifics differ in their attractiveness to males and females, and their behavioural reactions change with age. (2) A genetically based mechanism is involved in female recognition of kin.In a two-choice preference test, prepubertal males and females were more attracted to familiar than to unfamiliar odours of opposite-sex conspecifics, as manifested by more time spent sniffing familiar voles. As the young reached sexual maturity they shifted their odour preferences. Mature males and females preferred the novel odour of unrelated opposite-sex conspecifics to that of relatives. The results of experiments testing the second hypothesis indicate that females use a genetically based mechanism to recognise their kin. Young and mature females were able to recognise the odour of their biological but socially unknown fathers, and showed the same pattern of behaviour as females in previous experiments.The possible biological functions of kin recognition in bank voles are discussed.

Ovarian fluid mediates the temporal decline in sperm viability in a fish with sperm storage.

PubMed

Gasparini, Clelia; Evans, Jonathan P

2013-01-01

A loss of sperm viability and functionality during sperm transfer and storage within the female reproductive tract can have important fitness implications by disrupting fertilization and impairing offspring development and survival. Consequently, mechanisms that mitigate the temporal decline in sperm function are likely to be important targets of selection. In many species, ovarian fluid is known to regulate and maintain sperm quality. In this paper, we use the guppy Poecilia reticulata, a highly polyandrous freshwater fish exhibiting internal fertilization and sperm storage, to determine whether ovarian fluid (OF) influences the decline in sperm viability (the proportion of live sperm in the ejaculate) over time and whether any observed effects depend on male sexual ornamentation. To address these questions we used a paired experimental design in which ejaculates from individual males were tested in vitro both in presence and absence of OF. Our results revealed that the temporal decline in sperm viability was significantly reduced in the presence of OF compared to a saline control. This finding raises the intriguing possibility that OF may play a role in mediating the decline in sperm quality due to the deleterious effects of sperm ageing, although other possible explanations for this observation are discussed. Interestingly, we also show that the age-related decline in sperm viability was contingent on male sexual ornamentation; males with relatively high levels of iridescence (indicating higher sexual attractiveness) exhibited a more pronounced decline in sperm viability over time than their less ornamented counterparts. This latter finding offers possible insights into the functional basis for the previously observed trade-off between these key components of pre- and postcopulatory sexual selection.

A novel mechanism regulating a sexual signal: the testosterone-based inhibition of female sex pheromone expression in garter snakes.

PubMed

Parker, M Rockwell; Mason, Robert T

2014-08-01

Vertebrates communicate their sex to conspecifics through the use of sexually dimorphic signals, such as ornaments, behaviors and scents. Furthermore, the physiological connection between hormones and secondary sexual signal expression is key to understanding their dimorphism, seasonality and evolution. The red-sided garter snake (Thamnophis sirtalis parietalis) is the only reptile for which a described pheromone currently exists, and because garter snakes rely completely on the sexual attractiveness pheromone for species identification and mate choice, they constitute a unique model species for exploring the relationship between pheromones and the endocrine system. We recently demonstrated that estrogen can activate female pheromone production in male garter snakes. The purpose of this study was to determine the mechanism(s) acting to prevent female pheromone production in males. We found that castrated males (GX) are courted by wild males in the field and produce appreciable amounts of female sex pheromone. Furthermore, pheromone production is inhibited in castrates given testosterone implants (GX+T), suggesting that pheromone production is actively inhibited by the presence of testosterone. Lastly, testosterone supplementation alone (T) increased the production of several saturated methyl ketones in the pheromone but not the unsaturated ketones; this may indicate that saturated ketones are testosterone-activated components of the garter snake's skin lipid milieu. Collectively, our research has shown that pheromone expression in snakes results from two processes: activation by the feminizing steroid estradiol and inhibition by testosterone. We suggest that basal birds and garter snakes share common pathways of activation that modulate crucial intraspecific signals that originate from skin. Copyright © 2013 Elsevier Inc. All rights reserved.

Intra- and Trans-Generational Costs of Reduced Female Body Size Caused by Food Limitation Early in Life in Mites

PubMed Central

Walzer, Andreas; Schausberger, Peter

2013-01-01

Background Food limitation early in life may be compensated for by developmental plasticity resulting in accelerated development enhancing survival at the expense of small adult body size. However and especially for females in non-matching maternal and offspring environments, being smaller than the standard may incur considerable intra- and trans-generational costs. Methodology/Principal Findings Here, we evaluated the costs of small female body size induced by food limitation early in life in the sexually size-dimorphic predatory mite Phytoseiulus persimilis. Females are larger than males. These predators are adapted to exploit ephemeral spider mite prey patches. The intra- and trans-generational effects of small maternal body size manifested in lower maternal survival probabilities, decreased attractiveness for males, and a reduced number and size of eggs compared to standard-sized females. The trans-generational effects of small maternal body size were sex-specific with small mothers producing small daughters but standard-sized sons. Conclusions/Significance Small female body size apparently intensified the well-known costs of sexual activity because mortality of small but not standard-sized females mainly occurred shortly after mating. The disadvantages of small females in mating and egg production may be generally explained by size-associated morphological and physiological constraints. Additionally, size-assortative mate preferences of standard-sized mates may have rendered small females disproportionally unattractive mating partners. We argue that the sex-specific trans-generational effects were due to sexual size dimorphism – females are the larger sex and thus more strongly affected by maternal stress than the smaller males – and to sexually selected lower plasticity of male body size. PMID:24265745

Human urine and chicken feces as fruit fly (Diptera: Tephritidae) attractants for resource-poor fruit growers.

PubMed

Piñero, Jaime; Aluja, Martín; Vázquez, Alejandro; Equihua, Miguel; Varón, Jorge

2003-04-01

We evaluated human urine and chicken feces, two naturally occurring, inexpensive, and readily available substances, as baits for the capture of Anostrepha spp. (Diptera: Tephritidae) by using glass McPhail traps. Two studies were performed simultaneously in a commercial mango orchard in Veracruz, México. In the first study, we compared a 50% water dilution of human urine against hydrolyzed protein, both compounds at the fresh and 5-d-old stages, and water alone (control treatment). In the second study, we tested fresh chicken feces mixed with water, a torula yeast/borax solution at three different ages (1-4, 5-9, and 10-15 d), and water (control treatment). Both human urine and chicken feces were attractive to Anastrepha adults compared with water alone, but attracted two and three times fewer adults than hydrolyzed protein and torula yeast/borax, respectively. However, unlike torula yeast/borax, aging of human urine did not decrease its attractiveness. Five-day old human urine attracted numerically more A. serpentina females than males, similar numbers of A. obliqua males and females, and significantly more sexually immature A. obliqua females than mature ones. Chicken feces proved to be as attractive as the aged torula yeast/borax treatments for A. obliqua and A. serpentina. We argue that because both human urine and chicken feces are cost-free and can be easily obtained, they are viable, low-technology alternatives to costly commercial attractants, particularly for low-income growers or backyard farmers in Mexico and other Latin American countries.

Sexual orientation, fraternal birth order, and the maternal immune hypothesis: a review.

PubMed

Bogaert, Anthony F; Skorska, Malvina

2011-04-01

In 1996, psychologists Ray Blanchard and Anthony Bogaert found evidence that gay men have a greater number of older brothers than do heterosexual men. This "fraternal birth order" (FBO) effect has been replicated numerous times, including in non-Western samples. More recently, strong evidence has been found that the FBO effect is of prenatal origin. Although there is no direct support for the exact prenatal mechanism, the most plausible explanation may be immunological in origin, i.e., a mother develops an immune reaction against a substance important in male fetal development during pregnancy, and that this immune effect becomes increasingly likely with each male gestation. This immune effect is hypothesized to cause an alteration in (some) later born males' prenatal brain development. The target of the immune response may be molecules (i.e., Y-linked proteins) on the surface of male fetal brain cells, including in sites of the anterior hypothalamus, which has been linked to sexual orientation in other research. Antibodies might bind to these molecules and thus alter their role in typical sexual differentiation, leading some later born males to be attracted to men as opposed to women. Here we review evidence in favor of this hypothesis, including recent research showing that mothers of boys develop an immune response to one Y-linked protein (i.e., H-Y antigen; SMCY) important in male fetal development, and that this immune effect becomes increasingly likely with each additional boy to which a mother gives birth. We also discuss other Y-linked proteins that may be relevant if this hypothesis is correct. Finally, we discuss issues in testing the maternal immune hypothesis of FBO. Copyright © 2011 Elsevier Inc. All rights reserved.

Males adjust their signalling behaviour according to experience of male signals and male-female signal duets.

PubMed

Rebar, D; Rodríguez, R L

2016-04-01

Sexual signals are conspicuous sources of information about neighbouring competitors, and species in which males and females signal during pair formation provide various sources of public information to which individuals can adjust their behaviour. We performed two experiments with a duetting vibrational insect, Enchenopa binotata treehoppers (Hemiptera: Membracidae), to ask whether males adjust their signalling behaviour according to (1a) their own experience of competitors' signals, (1b) how females adjust their mate preferences on the basis of their experience of male signals (described in prior work), and/or (2) their own experience of female response signals to competitors' signals. We presented males with synthetic male signals of different frequencies and combinations thereof for 2 weeks. We recorded males a day after their last signal exposure, finding that (1a) male signal rate increased in response to experience of attractive competitors, but that (1b) male signal frequency did not shift in a manner consistent with how females adjust their mate preferences in those experience treatments. Second, we presented males with different male-female duets for 2 weeks, finding that (2) male signal length increased from experience of female duets with attractive competitors. Males thus make two types of adjustment according to two sources of public information: one provided by experience of male signals and another by experience of female responses to male signals. Signalling plasticity can generate feedback loops between the adjustments that males and females make, and we discuss the potential consequences of such feedback loops for the evolution of communication systems. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Broad Autism Phenotypic Traits and the Relationship to Sexual Orientation and Sexual Behavior.

PubMed

Qualls, Lydia R; Hartmann, Kathrin; Paulson, James F

2018-04-03

Individuals with higher levels of the broad autism phenotype (BAP) have some symptoms of autism spectrum disorder (ASD). Like individuals with ASD, people with higher-BAP may have fewer sexual experiences and may experience more same-sex attraction. This study measured BAP traits, sexual experiences, and sexual orientation in typically developing (TD) individuals to see if patterns of sexual behavior and sexual orientation in higher-BAP resemble those in ASD. Although BAP characteristics did not predict sexual experiences, one BAP measure significantly predicted sexual orientation, β = 0.22, t = 2.72, p = .007, controlling for demographic variables (R 2 change = .04, F = 7.41, p = .007), showing individuals with higher-BAP also reported increased same-sex attraction. This finding supports the hypothesis that individuals with higher-BAP resemble ASD individuals in being more likely than TD individuals to experience same-sex attraction.

Male sexual polymorphism, alternative reproductive tactics, and androgens in combtooth blennies (pisces: blenniidae).

PubMed

Oliveira, R F; Canario, A V; Grober, M S

2001-09-01

In species in which intense intermale competition for the access to females is present males of lower competitive ability may adopt alternative reproductive tactics (ART) to get access to mates. These ART translate in many cases into male sexual polymorphism, with individuals following distinctly different tactics. Usually two alternative male morphs can be recognized in species with ART: (1) bourgeois males that compete for access to mates invest in typically male behaviors, such as building elaborated nests or displaying ornaments; and (2) parasitic males that take advantage of the success of the bourgeois males in attracting females and attempt "sneaker" fertilizations (e.g., sneaker and satellite males). In combtooth blennies (Blenniidae) the co-occurrence of ART and male sexual polymorphism has been described for two temperate species: the peacock blenny, Salaria pavo, and the Azorean rock-pool blenny, Parablennius sanguinolentus parvicornis. Interestingly, while in the peacock blenny the alternative male morph adopts a sneaker tactic, in the rock-pool blenny parasitic males act as satellites to nest-holder males. Thus, this variation in the ART expressed in these two closely related species allows for a comparative study of the proximate and ultimate factors affecting the expression of the two ART. In this article we summarize the available information on androgen levels in bourgeois and parasitic males of natural populations of the two species and of recent studies on the effect of exogenous administration of androgens on tactic switching in parasitic males of the two species. The information is discussed within the frame of the relative plasticity hypothesis, which predicts that plastic alternative morphs should show differences in hormone levels and that the administration of sex steroids should be effective in promoting the switch from the parasitic to bourgeois tactic. The evidence is only partly consistent with this hypothesis. Alternatively, a social transduction hypothesis that better fits the available data on androgens and ART in teleost is proposed. It states that the observed differences in androgen levels between alternative morphs should not be interpreted as an organization vs activation effect of steroids, but rather as the limited vs lifelong responsiveness of the neuroendocrine axis to social regulation. Copyright 2001 Academic Press.

Heterosexual Men's Ratings of Sexual Attractiveness of Adolescent Girls: A Cross-Cultural Analysis.

PubMed

Bennett, Paul; Lowe, Rob; Petrova, Hristina

2015-11-01

Following an identical procedure to the one we previously reported (O'Donnell, Lowe, Brotherton, & Bennett, 2014), we examined ratings of sexual attraction to photographs of (the same) adolescent girls (Tanner stages 3-4) labelled as either 14-15 years or 16-17 years old, women, and men. Ratings were made by Bulgarian heterosexual men by pressing buttons on a response box which recorded the ratings made and the time in milliseconds taken to respond. Despite the age of sexual consent in Bulgaria being 14 years, the pattern of findings did not differ from those found in the UK, where the age of consent is 16 years. That is, mean ratings of the sexual attractiveness of the girls labelled as younger were lower than those of the (same) girls labelled as older, and those of the women. In addition, correlations revealed significantly longer responding times when younger girls (and men) were rated as more highly sexually attractive. These associations were reversed in response to the photographs of women. We take these findings to indicate an inhibitory effect arising from generalized sexual norms relating to the inappropriateness of sexual attraction to young girls; the greater the attraction, the higher the inhibition. This second replication of our initial findings suggests a robust effect that may be of benefit in exploration of pedophile or sex offender groups.

Sexual attitudes at northern latitudes

USGS Publications Warehouse

Lanctot, Richard B.

1998-01-01

Spreading his wings to reveal their pearly white undersides, the male buff-breasted sandpiper tilted his head to the sky, puffed out his chest, and uttered a series of soft "tick-ticks.” He then proceeded to stamp his feet and vibrate his wings as if the ground were quaking beneath him. Soon, three females, attracted by this courtship display, entered the curve of his embracing wings. They then spread their own wings and turned so their backs were against his chest, each jostling for the position closest to him. Just when mating seemed inevitable, a neighboring male rushed into the group, forcing all the birds into the air.

Mate choice could be random in female rats (Rattus norvegicus).

PubMed

Le Moëne, Olivia; Snoeren, Eelke M

2018-02-01

Female mate choice is often investigated in terms of reproductive success in order to understand how male characteristics contribute to sexual attractiveness. Previous studies have found that females rats prefer mating with their first encounter rather than males visited subsequently, suggesting that the rewarding value of this first encounter is enough to reinforce mating with the first partner. Using a multiple chambers paradigm, we allowed female rats to copulate freely with three males placed each in a different chamber. Then, we switched the males' position, and let the female interact with them freely again within the same session. We tested whether female mate choice was relying rather on a preferred male rat or on a preferred mating location. The results showed that females spent most time with the male in the chamber of 1st entry in the beginning, but as soon as male rats switched chambers, the female rat continued to copulate with the new male in the same chamber of 1st entry, instead of mating with her previously preferred male rat. This suggests that the male preference is an artefact of location preference. Therefore, female mate choice seems to be rather random than the consequence of an individual choice based on male characteristics. This finding, although contradictory with the intuitive feeling that mate choice is a crucial feature in sexual and reproductive behavior, is supported by several recent observations. In the coming years, behavioral neuroscience should bring light to the brain processes at work in random mate choice. Copyright © 2017 Elsevier Inc. All rights reserved.

Female mating preferences and offspring survival: testing hypotheses on the genetic basis of mate choice in a wild lekking bird.

PubMed

Sardell, Rebecca J; Kempenaers, Bart; Duval, Emily H

2014-02-01

Indirect benefits of mate choice result from increased offspring genetic quality and may be important drivers of female behaviour. 'Good-genes-for-viability' models predict that females prefer mates of high additive genetic value, such that offspring survival should correlate with male attractiveness. Mate choice may also vary with genetic diversity (e.g. heterozygosity) or compatibility (e.g. relatedness), where the female's genotype influences choice. The relative importance of these nonexclusive hypotheses remains unclear. Leks offer an excellent opportunity to test their predictions, because lekking males provide no material benefits and choice is relatively unconstrained by social limitations. Using 12 years of data on lekking lance-tailed manakins, Chiroxiphia lanceolata, we tested whether offspring survival correlated with patterns of mate choice. Offspring recruitment weakly increased with father attractiveness (measured as reproductive success, RS), suggesting attractive males provide, if anything, only minor benefits via offspring viability. Both male RS and offspring survival until fledging increased with male heterozygosity. However, despite parent-offspring correlation in heterozygosity, offspring survival was unrelated to its own or maternal heterozygosity or to parental relatedness, suggesting survival was not enhanced by heterozygosity per se. Instead, offspring survival benefits may reflect inheritance of specific alleles or nongenetic effects. Although inbreeding depression in male RS should select for inbreeding avoidance, mates were not less related than expected under random mating. Although mate heterozygosity and relatedness were correlated, selection on mate choice for heterozygosity appeared stronger than that for relatedness and may be the primary mechanism maintaining genetic variation in this system despite directional sexual selection. © 2014 John Wiley & Sons Ltd.

Intrasexual competition facilitates the evolution of alternative mating strategies in a colour polymorphic fish.

PubMed

Hurtado-Gonzales, Jorge L; Uy, J Albert C

2010-12-23

Intense competition for access to females can lead to males exploiting different components of sexual selection, and result in the evolution of alternative mating strategies (AMSs). Males of Poecilia parae, a colour polymorphic fish, exhibit five distinct phenotypes: drab-coloured (immaculata), striped (parae), structural-coloured (blue) and carotenoid-based red and yellow morphs. Previous work indicates that immaculata males employ a sneaker strategy, whereas the red and yellow morphs exploit female preferences for carotenoid-based colours. Mating strategies favouring the maintenance of the other morphs remain to be determined. Here, we report the role of agonistic male-male interactions in influencing female mating preferences and male mating success, and in facilitating the evolution of AMSs. Our study reveals variation in aggressiveness among P. parae morphs during indirect and direct interactions with sexually receptive females. Two morphs, parae and yellow, use aggression to enhance their mating success (i.e., number of copulations) by 1) directly monopolizing access to females, and 2) modifying female preferences after winning agonistic encounters. Conversely, we found that the success of the drab-coloured immaculata morph, which specializes in a sneak copulation strategy, relies in its ability to circumvent both male aggression and female choice when facing all but yellow males. Strong directional selection is expected to deplete genetic variation, yet many species show striking genetically-based polymorphisms. Most studies evoke frequency dependent selection to explain the persistence of such variation. Consistent with a growing body of evidence, our findings suggest that a complex form of balancing selection may alternatively explain the evolution and maintenance of AMSs in a colour polymorphic fish. In particular, this study demonstrates that intrasexual competition results in phenotypically distinct males exhibiting clear differences in their levels of aggression to exclude potential sexual rivals. By being dominant, the more aggressive males are able to circumvent female mating preferences for attractive males, whereas another male type incorporates subordinate behaviours that allow them to circumvent male aggression and female mating preferences. Together, these and previous results indicate that exploiting different aspects of social interactions may allow males to evolve distinct mating strategies and thus the long term maintenance of polymorphisms within populations.

Coming out for a third time: transmen, sexual orientation, and identity.

PubMed

Rowniak, Stefan; Chesla, Catherine

2013-04-01

Female-to-male (FTM) transgender persons are often assumed to have been lesbian in sexual orientation prior to transition and to have maintained a primary attraction for women after transition. However, limited research and anecdotal information from clinicians who work with FTM have indicated that many identify as gay men post-transition. This article described the results of a qualitative study that employed interviews with 17 FTM in order to understand their experience of transition and sexual orientation. Of the 17 participants, seven identified as lesbian prior to transition, three as heterosexual, and seven as bisexual or queer. After transition, 10 identified as gay men and the remaining seven identified as bisexual or queer. Four patterns of sexual behavior emerged from the data and were described and discussed. These patterns were named steadfast, aligned, shifted, and fluid. These findings bring additional options to the belief that there are two distinct types of transgender: a homosexual subtype and a nonhomosexual subtype.

Effect of normative masculinity on males' dysfunctional sexual beliefs, sexual attitudes, and perceptions of sexual functioning.

PubMed

Clarke, Michael J; Marks, Anthony D G; Lykins, Amy D

2015-01-01

Male sexual dysfunction is a prevalent and distressing condition, which may be exacerbated by the sufferer's perceptions of masculinity and normative sexual behavior. This study sought to investigate the effect of social context on males' beliefs regarding sexual behavior. The research examined the effect of male role modeling and masculine cues on males' dysfunctional sexual beliefs, sexual attitudes, and self-perceptions of sexual functioning. A sample of 140 male participants, with a mean age of 29 years, was exposed to pictorial and verbal cues that presented different versions of male behavior across three conditions. Results indicated that males exposed to models and cues of traditional masculinity showed significantly increased levels of dysfunctional sexual beliefs and traditional sexual attitudes relative to males exposed to models of modern masculinity. Results also indicated that males exposed to traditional masculine stimuli reported lower levels of sexual inhibition due to fear of performance failure than males exposed to models of modern masculinity. The potential role of social context is discussed in the development and maintenance of male sexual dysfunction and its implications for treatment.

Fertility knowledge and intentions to have children in a national study of Australian secondary school students.

PubMed

Heywood, Wendy; Pitts, Marian K; Patrick, Kent; Mitchell, Anne

2016-10-01

This paper reports on fertility knowledge and intentions to have children among a national sample of students in years 10-12. Data were from the Fifth National Survey of Australian Secondary Students and Sexual Health. Students identified factors that could affect fertility, if they wanted children and at what age. Most students wanted to have children (77%). Of those who wanted children or were unsure (n=1,780), 54% were able to identify six of eight factors that could affect fertility. Male students had poorer knowledge than females. Poorer knowledge was also reported by male students who were born overseas or used marijuana and by female students who were sexually active or religious. More than half the students (59%) wanted their first child aged 25-29, while 19% wanted their first child after 30. Intentions to have children at an earlier age were associated with being religious, sexually active (females), and using marijuana (males). Students not exclusively attracted to the opposite sex were more likely to want children at an older age. Most students typically want children in their late 20s. Many were unaware of factors that could affect their fertility and there was a mismatch between intentions and likely behaviour. These factors could be addressed as part of relationship education. © 2016 Public Health Association of Australia.

Straight but Not Narrow; Within-Gender Variation in the Gender-Specificity of Women’s Sexual Response

PubMed Central

Chivers, Meredith L.; Bouchard, Katrina N.; Timmers, Amanda D.

2015-01-01

Gender differences in the specificity of sexual response have been a primary focus in sexual psychophysiology research, however, within-gender variability suggests sexual orientation moderates category-specific responding among women; only heterosexual women show gender-nonspecific genital responses to sexual stimuli depicting men and women. But heterosexually-identified or “straight” women are heterogeneous in their sexual attractions and include women who are exclusively androphilic (sexually attracted to men) and women who are predominantly androphilic with concurrent gynephilia (sexually attracted to women). It is therefore unclear if gender-nonspecific responding is found in both exclusively and predominantly androphilic women. The current studies investigated within-gender variability in the gender-specificity of women’s sexual response. Two samples of women reporting concurrent andro/gynephilia viewed (Study 1, n = 29) or listened (Study 2, n = 30) to erotic stimuli varying by gender of sexual partner depicted while their genital and subjective sexual responses were assessed. Data were combined with larger datasets of predominantly gyne- and androphilic women (total N = 78 for both studies). In both studies, women reporting any degree of gynephilia, including those who self-identified as heterosexual, showed significantly greater genital response to female stimuli, similar to predominantly gynephilic women; gender-nonspecific genital response was observed for exclusively androphilic women only. Subjective sexual arousal patterns were more variable with respect to sexual attractions, likely reflecting stimulus intensity effects. Heterosexually-identified women are therefore not a homogenous group with respect to sexual responses to gender cues. Implications for within-gender variation in women’s sexual orientation and sexual responses are discussed. PMID:26629910

Straight but Not Narrow; Within-Gender Variation in the Gender-Specificity of Women's Sexual Response.

PubMed

Chivers, Meredith L; Bouchard, Katrina N; Timmers, Amanda D

2015-01-01

Gender differences in the specificity of sexual response have been a primary focus in sexual psychophysiology research, however, within-gender variability suggests sexual orientation moderates category-specific responding among women; only heterosexual women show gender-nonspecific genital responses to sexual stimuli depicting men and women. But heterosexually-identified or "straight" women are heterogeneous in their sexual attractions and include women who are exclusively androphilic (sexually attracted to men) and women who are predominantly androphilic with concurrent gynephilia (sexually attracted to women). It is therefore unclear if gender-nonspecific responding is found in both exclusively and predominantly androphilic women. The current studies investigated within-gender variability in the gender-specificity of women's sexual response. Two samples of women reporting concurrent andro/gynephilia viewed (Study 1, n = 29) or listened (Study 2, n = 30) to erotic stimuli varying by gender of sexual partner depicted while their genital and subjective sexual responses were assessed. Data were combined with larger datasets of predominantly gyne- and androphilic women (total N = 78 for both studies). In both studies, women reporting any degree of gynephilia, including those who self-identified as heterosexual, showed significantly greater genital response to female stimuli, similar to predominantly gynephilic women; gender-nonspecific genital response was observed for exclusively androphilic women only. Subjective sexual arousal patterns were more variable with respect to sexual attractions, likely reflecting stimulus intensity effects. Heterosexually-identified women are therefore not a homogenous group with respect to sexual responses to gender cues. Implications for within-gender variation in women's sexual orientation and sexual responses are discussed.

Familial patterning and prevalence of male androphilia among Istmo Zapotec men and muxes.

PubMed

Gómez, Francisco R; Semenyna, Scott W; Court, Lucas; Vasey, Paul L

2018-01-01

Male androphilia (i.e., male sexual attraction to other adult males) is known to cluster within families. Some studies demonstrate that male androphilia clusters in both the paternal and maternal familial lines, whereas other studies demonstrated that it clusters only in the latter. Most of these studies were conducted in Euro-American populations where fertility is low and the sexual orientation of male relatives can sometimes be difficult to ascertain. These two factors can potentially confound the results of such studies. To address these limitations, we examined the familial patterning of male androphilia among the Istmo Zapotec of Oaxaca, Mexico--a high fertility, non-Euro-American population where androphilic males are known locally as muxes, a third gender category. The Istmo Zapotec recognize two types of muxes--muxe gunaa and muxe nguiiu--who typify the transgender and cisgender forms of male androphilia, respectively. We compared the familial patterning of male androphilia between muxe gunaa and muxe nguiiu, as well as between gynephilic men and muxes (both cisgender and transgender forms combined). Istmo Zapotec muxe gunaa and muxe nguiiu exhibit similar familial patterning of male androphilia. Overall, muxes were characterized by significantly more muxe relatives than gynephilic men. This familial patterning was equivalent in both the paternal and maternal lines of muxes. The population prevalence rate of male androphilia was estimated to fall between 3.37-6.02% in the Istmo Zapotec. This is the first study that has compared cisgender and transgender androphilic males from the same high fertility population and demonstrated that the two do not differ with respect to the familial patterning of male androphilia.

Familial patterning and prevalence of male androphilia among Istmo Zapotec men and muxes

PubMed Central

Semenyna, Scott W.; Court, Lucas; Vasey, Paul L.

2018-01-01

Male androphilia (i.e., male sexual attraction to other adult males) is known to cluster within families. Some studies demonstrate that male androphilia clusters in both the paternal and maternal familial lines, whereas other studies demonstrated that it clusters only in the latter. Most of these studies were conducted in Euro-American populations where fertility is low and the sexual orientation of male relatives can sometimes be difficult to ascertain. These two factors can potentially confound the results of such studies. To address these limitations, we examined the familial patterning of male androphilia among the Istmo Zapotec of Oaxaca, Mexico––a high fertility, non-Euro-American population where androphilic males are known locally as muxes, a third gender category. The Istmo Zapotec recognize two types of muxes––muxe gunaa and muxe nguiiu––who typify the transgender and cisgender forms of male androphilia, respectively. We compared the familial patterning of male androphilia between muxe gunaa and muxe nguiiu, as well as between gynephilic men and muxes (both cisgender and transgender forms combined). Istmo Zapotec muxe gunaa and muxe nguiiu exhibit similar familial patterning of male androphilia. Overall, muxes were characterized by significantly more muxe relatives than gynephilic men. This familial patterning was equivalent in both the paternal and maternal lines of muxes. The population prevalence rate of male androphilia was estimated to fall between 3.37–6.02% in the Istmo Zapotec. This is the first study that has compared cisgender and transgender androphilic males from the same high fertility population and demonstrated that the two do not differ with respect to the familial patterning of male androphilia. PMID:29466410

Tobacco Use and Sexual Orientation in a National Cross-sectional Study: Age, Race/Ethnicity, and Sexual Identity-Attraction Differences.

PubMed

McCabe, Sean Esteban; Matthews, Alicia K; Lee, Joseph G L; Veliz, Phil; Hughes, Tonda L; Boyd, Carol J

2018-04-09

The purpose of this study is to determine the past-year prevalence estimates of any nicotine/tobacco use, cigarette smoking, and DSM-5 tobacco use disorder based on sexual identity among U.S. adults, and to examine potential variations in these estimates by age, race/ethnicity, and sexual identity-attraction concordance/discordance. The 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions collected data via in-person interviews with a cross-sectional nationally representative sample of non-institutionalized adults (response rate=60.1%) and analyses for the present study were conducted in 2017. Any past-year nicotine/tobacco use, cigarette smoking, and DSM-5 tobacco use disorder were most prevalent among sexual minority-identified adults compared with heterosexual-identified adults, with notable variations based on sex, age, race/ethnicity, and sexual identity-attraction discordance. Elevated rates of any nicotine/tobacco use, cigarette smoking, and DSM-5 tobacco use disorder among sexual minorities were most prevalent among younger lesbian women and gay men, and all age groups of bisexual men and women. The odds of any nicotine/tobacco use, cigarette smoking, and DSM-5 tobacco use disorder were significantly greater among sexual identity-attraction discordant women and significantly lower among sexual identity-attraction discordant men. These findings provide valuable new information about sexual minority subgroups, such as self-identified bisexual older adults and sexual identity-attraction discordant women, that appear to be at higher risk for adverse smoking-related health consequences as a result of their elevated rates of cigarette smoking. Additional attention is warranted to examine these high-risk subpopulations prospectively and, if the results are replicated with larger samples, this information can be used to target smoking-cessation and lung cancer screening efforts. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

The number of recent sex partners among bisexual men in the United States.

PubMed

Jeffries, William L

2011-09-01

Little is known regarding bisexual men's number of recent sex partners, a risk factor for HIV and other STDs. Furthermore, it is unclear if bisexual men have more partners than heterosexual or homosexual men, and whether partner number varies by measures of sexual behavior, identity and attraction. Sexual orientation-defined separately by sexual behavior during the past year, identity and attraction-was assessed for 3,875 sexually active men aged 15-44 who had participated in the 2002 National Survey of Family Growth. Chi-square and t tests examined differences in background characteristics, behavioral risk factors and number of past-year sex partners by sexual orientation according to each definition. Multivariate ordinary least-squares regression was used to assess predictors of the number of partners. When sexual identity and attraction were controlled for, behaviorally bisexual men were predicted to have had 3.1 more past-year partners than behaviorally heterosexual men and 2.6 more than behaviorally homosexual men. After controlling for sexual identity and behavior, bisexual-attracted men had had 0.7 fewer partners than homosexual-attracted men. In a model including background characteristics and behavioral risk factors, behaviorally bisexual men were predicted to have had 2.5-2.6 more partners than others. Neither bisexual identity nor bisexual attraction independently predicted the number of recent partners. The way in which bisexuality relates to men's number of recent sex partners depends on how sexual orientation is measured. Interventions to reduce behaviorally bisexual men's number of partners will likely lessen their risk for HIV and other STDs. Copyright © 2011 by the Guttmacher Institute.

Online or off-line victimisation and psychological well-being: a comparison of sexual-minority and heterosexual youth.

PubMed

Priebe, Gisela; Svedin, Carl Göran

2012-10-01

The purpose of this study was to compare sexual-minority and heterosexual youths' exposure to sexual abuse off-line, problematic sexual meetings off-line with person/s met online and online harassment with regard to prevalence, psychological well-being and support seeking. A nationally representative sample of 3,432 Swedish high school seniors completed an anonymous school-based survey about sexuality, health, sexual abuse and online-related sexual victimisation or harassment. Sexual-minority adolescents reported a greater rate of sexual abuse, problematic sexual meetings off-line with person/s met online and online harassment, compared to heterosexual youth. When compared to non-victimised heterosexual adolescents, victimised heterosexual adolescents and non-victimised and victimised sexual-minority adolescents reported more psychiatric symptoms, lower self-esteem and a weaker sense of coherence. Same-sex sexual orientation was related to more psychiatric symptoms, lower self-esteem and a weaker sense of coherence even when controlled for victimisation and gender. Compared to victimised heterosexual adolescents, victimised sexual-minority adolescents were more likely to seek support because of sexual abuse (females) or Internet-related problems (males and females). Results for sexual-minority youth were basically the same whether sexual orientation was assessed as sexual identity or as sexual or emotional attraction. Health care providers are challenged to not only provide the same care to sexual-minority youth who seek counselling or psychiatric treatment for mental health problems or problems related to victimisation that all adolescents should receive but also to find ways to address topics like prevention of sexual abuse and risk-taking behaviour online or off-line.

Depressive symptoms among Hong Kong adolescents: relation to atypical sexual feelings and behaviors, gender dissatisfaction, pubertal timing, and family and peer relationships.

PubMed

Lam, T H; Stewart, Sunita M; Leung, Gabriel M; Lee, Peter W H; Wong, Joy P S; Ho, L M; Youth Sexuality Task Force

2004-10-01

A representative community sample of Hong Kong boys (n = 1,024) and girls (n = 1,403), age 14-18 years, provided information regarding same-sex attraction, gender dissatisfaction, pubertal timing, early experience with sexual intercourse, and depressive symptoms. They also rated the quality of their family and peer relationships and self-perceived attractiveness. Depressive symptoms were higher in youths reporting same-sex attraction, gender dissatisfaction, early pubertal maturation, and early sexual intercourse. Family relationships were less satisfactory for those who reported same-sex attraction, gender dissatisfaction, and early sexual intercourse, and peer relationships were also worse for those who reported gender dissatisfaction. In multivariate analyses, same-sex attraction, early sexual intercourse, and early pubertal maturation were unique and direct contributors to depressive symptoms; however, gender dissatisfaction's association with depressive symptoms was largely accounted for by shared correlations with negative family and peer relationships. The multivariate model explained 11% of the variance of depressive symptoms. These findings offer a preliminary documentation of the prevalence and correlates of atypical sexual self-assessments and behavior among adolescents in Hong Kong. Such information is important if theories of sexual identity and risk factors for depressive symptoms are to have cross-cultural utility. Copyright 2004 Springer Science + Business Media, Inc.

Ornament size and colour as alternative strategies for effective communication in gliding lizards.

PubMed

Klomp, D A; Ord, T J; Das, I; Diesmos, A; Ahmad, N; Stuart-Fox, D

2016-09-01

Sexual ornamentation needs to be conspicuous to be effective in attracting potential mates and defending territories and indeed, a multitude of ways exists to achieve this. Two principal mechanisms for increasing conspicuousness are to increase the ornament's colour or brightness contrast against the background and to increase the size of the ornament. We assessed the relationship between the colour and size of the dewlap, a large extendible throat-fan, across a range of species of gliding lizards (Agamidae; genus Draco) from Malaysia and the Philippines. We found a negative relationship across species between colour contrast against the background and dewlap size in males, but not in females, suggesting that males of different species use increasing colour contrast and dewlap size as alternative strategies for effective communication. Male dewlap size also increases with increasing sexual size dimorphism, and dewlap colour and brightness contrast increase with increasing sexual dichromatism in colour and brightness, respectively, suggesting that sexual selection may act on both dewlap size and colour. We further found evidence that relative predation intensity, as measured from predator attacks on models placed in the field, may play a role in the choice of strategy (high chromatic contrast or large dewlap area) a species employs. More broadly, these results highlight that each component in a signal (such as colour or size) may be influenced by different selection pressures and that by assessing components individually, we can gain a greater understanding of the evolution of signal diversity. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

The impact of baby schema on perceived attractiveness, beauty, and cuteness in female adults.

PubMed

Kuraguchi, Kana; Taniguchi, Kosuke; Ashida, Hiroshi

2015-01-01

Beauty and cuteness are considered to represent different aspects of attractiveness and to be distinguishable from each other by their respective reliance on neonate and sexually mature features found in attractive faces. In this study, we investigated whether baby schema features in adult faces affect not only cuteness, but also beauty and attractiveness. We also investigated possible differences among attractiveness, beauty, and cuteness, and possible effects of perceived youth on these judgments. Results showed that baby schema features affected judgments of attractiveness, beauty, and cuteness, but that perceived youth did not significantly influence these judgments. Furthermore, the effect of each facial feature differed across rating types with the participants' naïve interpretation of rating categories. This suggests that beauty predominantly refers to sexual attraction, while attractiveness refers to a non-sexual attraction regardless of participants' gender. However, gender differences may exist in judging cuteness. Therefore, expressions related to attractiveness may incorporate different elements and this distinction may not be fully shared across gender.

Aging modulates cuticular hydrocarbons and sexual attractiveness in Drosophila melanogaster

PubMed Central

Kuo, Tsung-Han; Yew, Joanne Y.; Fedina, Tatyana Y.; Dreisewerd, Klaus; Dierick, Herman A.; Pletcher, Scott D.

2012-01-01

SUMMARY Attractiveness is a major component of sexual selection that is dependent on sexual characteristics, such as pheromone production, which often reflect an individual’s fitness and reproductive potential. Aging is a process that results in a steady decline in survival and reproductive output, yet little is known about its effect on specific aspects of attractiveness. In this report we asked how aging impacts pheromone production and sexual attractiveness in Drosophila melanogaster. Evidence suggests that key pheromones in Drosophila are produced as cuticular hydrocarbons (CHC), whose functions in attracting mates and influencing behavior have been widely studied. We employed gas chromatography/mass spectrometry and laser desorption/ionization mass spectrometry to show that the composition of D. melanogaster CHC is significantly affected by aging in both sexes and that these changes are robust to different genetic backgrounds. Aging affected the relative levels of many individual CHC, and it shifted overall hydrocarbon profiles to favor compounds with longer chain lengths. We also show that the observed aging-related changes in CHC profiles are responsible for a significant reduction in sexual attractiveness. These studies illuminate causal links among pheromones, aging and attractiveness and suggest that CHC production may be an honest indicator of animal health and fertility. PMID:22323204

Same-sex sexuality and psychiatric disorders in the second Netherlands Mental Health Survey and Incidence Study (NEMESIS-2).

PubMed

Sandfort, Theo G M; de Graaf, Ron; Ten Have, Margreet; Ransome, Yusuf; Schnabel, Paul

2014-12-01

Sexual orientation has been shown to be a risk factor for psychiatric disorders. This study compared whether sexual orientation-related disparities in the prevalence of psychiatric disorders are similar based on homosexual behavior versus attraction and tested whether, with increased acceptance of homosexuality, these disparities have diminished over time. The Composite International Diagnostic Interview 3.0 was administered with a total of 6,646 Dutch persons, aged 18 to 64 years. Between 2.0% and 2.5% of the participants reported same-sex sexual behavior in the preceding year or same-sex attraction. Homosexually active persons and persons with same-sex attraction reported a higher prevalence of disorders than heterosexual persons. There were more disparities in the prevalence of disorders based on sexual attraction than based on sexual behavior. Comparing these results with a previous study, showed that no significant changes over time have occurred in the pattern of health disparities. Sexual orientation continues to be a risk factor for psychiatric disorders, stressing the need for understanding the origins of these disparities.

2,3-Hexanediols as Sex Attractants and a Female-produced Sex Pheromone for Cerambycid Beetles in the Prionine Genus Tragosoma

PubMed Central

Barbour, James D.; McElfresh, J. Steven; Moreira, Jardel A.; Swift, Ian; Wright, Ian M.; Žunič, Alenka; Mitchell, Robert F.; Graham, Elizabeth E.; Alten, Ronald L.; Millar, Jocelyn G.; Hanks, Lawrence M.

2013-01-01

Recent work suggests that closely related cerambycid species often share pheromone components, or even produce pheromone blends of identical composition. However, little is known of the pheromones of species in the subfamily Prioninae. During field bioassays in California, males of three species in the prionine genus Tragosoma were attracted to 2,3-hexanediols, common components of male-produced aggregation pheromones of beetles in the subfamily Cerambycinae. We report here that the female-produced sex pheromone of Tragosoma depsarium “sp. nov. Laplante” is (2R,3R)-2,3-hex-anediol, and provide evidence from field bioassays and electro-antennography that the female-produced pheromone of both Tragosoma pilosicorne Casey and T depsarium “harrisi” LeConte may be (2S,3R)-2,3-hexanediol. Sexual dimorphism in the sculpting of the prothorax suggests that the pheromone glands are located in the prothorax of females. This is the second sex attractant pheromone structure identified from the subfamily Prioninae, and our results provide further evidence of pheromonal parsimony within the Cerambycidae, in this case extending across both subfamily and gender lines. PMID:22923142

Sex Ratio Bias Leads to the Evolution of Sex Role Reversal in Honey Locust Beetles.

PubMed

Fritzsche, Karoline; Booksmythe, Isobel; Arnqvist, Göran

2016-09-26

The reversal of conventional sex roles was enigmatic to Darwin, who suggested that it may evolve when sex ratios are female biased [1]. Here we present direct evidence confirming Darwin's hypothesis. We investigated mating system evolution in a sex-role-reversed beetle (Megabruchidius dorsalis) using experimental evolution under manipulated sex ratios and food regimes. In female-biased populations, where reproductive competition among females was intensified, females evolved to be more attractive and the sex roles became more reversed. Interestingly, female-specific mating behavior evolved more rapidly than male-specific mating behavior. We show that sexual selection due to reproductive competition can be strong in females and can target much the same traits as in males of species with conventional mating systems. Our study highlights two central points: the role of ecology in directing sexual selection and the role that females play in mating system evolution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Men With a Terminal Illness Relax Their Criteria for Facial Attractiveness

PubMed Central

Danel, Dariusz P.; Siennicka, Agnieszka E.; Fedurek, Pawel; Frackowiak, Tomasz; Sorokowski, Piotr; Jankowska, Ewa A.; Pawlowski, Boguslaw

2017-01-01

According to the life history paradigm, in life-threatening conditions, sexual selection criteria are relaxed in order to increase the probability of a last resort reproduction, ultimately contributing to reproductive success. This should be reflected in loosened mating preferences — a process observed in nonhuman animals. Studies investigating this aspect in humans, however, are scarce. This study explored the aesthetic preferences towards facial and nonfacial stimuli in terminally ill patients with heart failure (HF) and their healthy, same-sex peers. The aim was to examine if these two groups of men demonstrate different patterns of aesthetic judgments. Using a 7-point scale, 65 male patients with HF and 143 healthy men evaluated the perceived attractiveness of 15 photographs (five adult male faces, five adult female faces, and five nonfacial pictures). A mixed-design analysis of variance was run to assess group differences in aesthetic preferences. Compared to healthy controls, stimuli. HF patients rated the pictures using significantly higher scores, but this applied only to male and female, but not nonfacial, stimuli. We propose that lower criteria for facial attractiveness in HF patients are linked to relaxation of mate preferences as a result of a life-threatening conditions, and that this process can be an adaptive mating strategy from an ultimate, evolutionary perspective. However, other mechanisms (e.g., seeking social support) may be also responsible for the observed patterns. PMID:28625113

Men With a Terminal Illness Relax Their Criteria for Facial Attractiveness.

PubMed

Danel, Dariusz P; Siennicka, Agnieszka E; Fedurek, Pawel; Frackowiak, Tomasz; Sorokowski, Piotr; Jankowska, Ewa A; Pawlowski, Boguslaw

2017-07-01

According to the life history paradigm, in life-threatening conditions, sexual selection criteria are relaxed in order to increase the probability of a last resort reproduction, ultimately contributing to reproductive success. This should be reflected in loosened mating preferences - a process observed in nonhuman animals. Studies investigating this aspect in humans, however, are scarce. This study explored the aesthetic preferences towards facial and nonfacial stimuli in terminally ill patients with heart failure (HF) and their healthy, same-sex peers. The aim was to examine if these two groups of men demonstrate different patterns of aesthetic judgments. Using a 7-point scale, 65 male patients with HF and 143 healthy men evaluated the perceived attractiveness of 15 photographs (five adult male faces, five adult female faces, and five nonfacial pictures). A mixed-design analysis of variance was run to assess group differences in aesthetic preferences. Compared to healthy controls, stimuli. HF patients rated the pictures using significantly higher scores, but this applied only to male and female, but not nonfacial, stimuli. We propose that lower criteria for facial attractiveness in HF patients are linked to relaxation of mate preferences as a result of a life-threatening conditions, and that this process can be an adaptive mating strategy from an ultimate, evolutionary perspective. However, other mechanisms (e.g., seeking social support) may be also responsible for the observed patterns.

Using Computer Simulations for Investigating a Sex Education Intervention: An Exploratory Study

PubMed Central

Bullock, Seth; Graham, Cynthia A; Ingham, Roger

2017-01-01

Background Sexually transmitted infections (STIs) are ongoing concerns. The best method for preventing the transmission of these infections is the correct and consistent use of condoms. Few studies have explored the use of games in interventions for increasing condom use by challenging the false sense of security associated with judging the presence of an STI based on attractiveness. Objectives The primary purpose of this study was to explore the potential use of computer simulation as a serious game for sex education. Specific aims were to (1) study the influence of a newly designed serious game on self-rated confidence for assessing STI risk and (2) examine whether this varied by gender, age, and scores on sexuality-related personality trait measures. Methods This paper undertook a Web-based questionnaire study employing between and within subject analyses. A Web-based platform hosted in the United Kingdom was used to deliver male and female stimuli (facial photographs) and collect data. A convenience sample group of 66 participants (64%, 42/66) male, mean age 22.5 years) completed the Term on the Tides, a computer simulation developed for this study. Participants also completed questionnaires on demographics, sexual preferences, sexual risk evaluations, the Sexual Sensation Seeking Scale (SSS), and the Sexual Inhibition Subscale 2 (SIS2) of the Sexual Inhibition/Sexual Excitation Scales-Short Form (SIS/SES - SF). Results The overall confidence of participants to evaluate sexual risks reduced after playing the game (P<.005). Age and personality trait measures did not predict the change in confidence of evaluating risk. Women demonstrated larger shifts in confidence than did men (P=.03). Conclusions This study extends the literature by investigating the potential of computer simulations as a serious game for sex education. Engaging in the Term on the Tides game had an impact on participants’ confidence in evaluating sexual risks. PMID:28468747

Prenatal Influences on Human Sexual Orientation: Expectations versus Data.

PubMed

Breedlove, S Marc

2017-08-01

In non-human vertebrate species, sexual differentiation of the brain is primarily driven by androgens such as testosterone organizing the brains of males in a masculine fashion early in life, while the lower levels of androgen in developing females organize their brains in a feminine fashion. These principles may be relevant to the development of sexual orientation in humans, because retrospective markers of prenatal androgen exposure, namely digit ratios and otoacoustic emissions, indicate that lesbians, on average, were exposed to greater prenatal androgen than were straight women. Thus, the even greater levels of prenatal androgen exposure experienced by fetal males may explain why the vast majority of them grow up to be attracted to women. However, the same markers indicate no significant differences between gay and straight men in terms of average prenatal androgen exposure, so the variance in orientation in men cannot be accounted for by variance in prenatal androgen exposure, but may be due to variance in response to prenatal androgens. These data contradict several popular notions about human sexual orientation. Sexual orientation in women is said to be fluid, sometimes implying that only social influences in adulthood are at work, yet the data indicate prenatal influences matter as well. Gay men are widely perceived as under-masculinized, yet the data indicate they are exposed to as much prenatal androgen as straight men. There is growing sentiment to reject "binary" conceptions of human sexual orientations, to emphasize instead a spectrum of orientations. Yet the data indicate that human sexual orientation is sufficiently polarized that groups of lesbians, on average, show evidence of greater prenatal androgen exposure than groups of straight women, while groups of gay men have, on average, a greater proportion of brothers among their older siblings than do straight men.

Stability of Sexual Attractions Across Different Timescales: The Roles of Bisexuality and Gender.

PubMed

Diamond, Lisa M; Dickenson, Janna A; Blair, Karen L

2017-01-01

We examined the stability of same-sex and other-sex attractions among 294 heterosexual, lesbian, gay, and bisexual men and women between the ages of 18 and 40 years. Participants used online daily diaries to report the intensity of each day's strongest same-sex and other-sex attraction, and they also reported on changes they recalled experiencing in their attractions since adolescence. We used multilevel dynamical systems models to examine individual differences in the stability of daily attractions (stability, in these models, denotes the tendency for attractions to "self-correct" toward a person-specific setpoint over time). Women's attractions showed less day-to-day stability than men's, consistent with the notion of female sexual fluidity (i.e., heightened erotic sensitivity to situational and contextual influences). Yet, women did not recollect larger post-adolescent changes in sexual attractions than did men, and larger recollected post-adolescent changes did not predict lower day-to-day stability in the sample as a whole. Bisexually attracted individuals recollected larger post-adolescent changes in their attractions, and they showed lower day-to-day stability in attractions to their "less-preferred" gender, compared to individuals with exclusive same-sex or exclusive other-sex attractions. Our results suggest that both gender and bisexuality have independent influences on sexual fluidity, but these influences vary across short versus long timescales, and they also differ for attractions to one's "more-preferred" versus "less-preferred" gender.

Kin recognition and adjustment of reproductive effort in zebra finches.

PubMed

Arct, Aneta; Rutkowska, Joanna; Martyka, Rafal; Drobniak, Szymon M; Cichon, Mariusz

2010-12-23

The differential allocation theory predicts that females should invest more in offspring produced with attractive partners, and a number of studies support this prediction in birds. Females have been shown to increase reproductive investment when mated to males showing elaborated sexual traits. However, mate attractiveness might also depend on the interaction between male and female genotypes. Accordingly, females should invest more in offspring sired by individuals that are genetically dissimilar or carry superior alleles. Here, we show in zebra finches (Taeniopygia guttata) that pairs of unfamiliar genetic brothers and sisters are less likely to reproduce in comparison with randomly mated pairs. Among the brother-sister pairs, those that attempted to breed laid smaller clutches and of lower total clutch mass. Our results provide the first experimental evidence that females adjust their reproductive effort in response to the genetic similarity of their partners. Importantly, these results imply a female ability to assess relatedness of a social mate without prior association.

Kin recognition and adjustment of reproductive effort in zebra finches

PubMed Central

Arct, Aneta; Rutkowska, Joanna; Martyka, Rafał; Drobniak, Szymon M.; Cichoń, Mariusz

2010-01-01

The differential allocation theory predicts that females should invest more in offspring produced with attractive partners, and a number of studies support this prediction in birds. Females have been shown to increase reproductive investment when mated to males showing elaborated sexual traits. However, mate attractiveness might also depend on the interaction between male and female genotypes. Accordingly, females should invest more in offspring sired by individuals that are genetically dissimilar or carry superior alleles. Here, we show in zebra finches (Taeniopygia guttata) that pairs of unfamiliar genetic brothers and sisters are less likely to reproduce in comparison with randomly mated pairs. Among the brother–sister pairs, those that attempted to breed laid smaller clutches and of lower total clutch mass. Our results provide the first experimental evidence that females adjust their reproductive effort in response to the genetic similarity of their partners. Importantly, these results imply a female ability to assess relatedness of a social mate without prior association. PMID:20573618

The effect of female wings on male courtship behavior in the cricket Gryllus bimaculatus

NASA Astrophysics Data System (ADS)

Itoh, Masanori; Murakami, Shio

2002-03-01

Sexual dimorphism exists in the shape and the structure of the forewings of the cricket (Gryllus bimaculatus). However, the functional significance of the wings in the G. bimaculatus female has been unclear. In common blue butterflies (Polyommatus icarus), wings in females have been suggested as being important for attracting males. To test whether female crickets need wings for conspecific males to recognize them and initiate mating behavior, we removed all wings from females and observed the behavior of males towards them. Most males (87.5%) showed mating behavior towards the wingless females: they produced courtship song and transferred spermatophores to the wingless females. Similarly, 88.5% of the males showed mating behavior towards intact females. When males were placed with both a wingless female and an intact female, no significant difference was detected in male mate choice. The findings demonstrate that the wing of the G. bimaculatus female is not necessary for female recognition by conspecific males and the initiation of male mating behavior, and that it is not important in male mate choice.