Facial Structure Predicts Sexual Orientation in Both Men and Women

The effect of sexual orientation on voice acoustic properties

Introduction

Previous research has investigated sexual orientation differences in the acoustic properties of individuals' voices, often theorizing that homosexuals of both sexes would have voice properties mirroring those of heterosexuals of the opposite sex. Findings were mixed, but many of these studies have methodological limitations including small sample sizes, use of recited passages instead of natural speech, or grouping bisexual and homosexual participants together for analyses.

Methods

To address these shortcomings, the present study examined a wide range of acoustic properties in the natural voices of 142 men and 175 women of varying sexual orientations, with sexual orientation treated as a continuous variable throughout.

Results

Homosexual men had less breathy voices (as indicated by a lower harmonics-to-noise ratio) and, contrary to our prediction, a lower voice pitch and narrower pitch range than heterosexual men. Homosexual women had lower F4 formant frequency (vocal tract resonance or so-called overtone) in overall vowel production, and rougher voices (measured via jitter and spectral tilt) than heterosexual women. For those sexual orientation differences that were statistically significant, bisexuals were in-between heterosexuals and homosexuals. No sexual orientation differences were found in formants F1-F3, cepstral peak prominence, shimmer, or speech rate in either sex.

Discussion

Recommendations for future "natural voice" investigations are outlined.

The Fertility Fix: the Boom in Facial-matching Algorithms for Donor Selection in Assisted Reproduction in Spain

This article reads the uptake of facial-matching algorithms by fertility clinics in Spain through the lens of 'the fertility fix': a software fix to the social reconfiguration of kinship and a fixed capital investment made by competing fertility companies and firms. 'The fertility fix' is proposed as a critical, ethical lens through which to situate algorithmic facial-matching in assisted reproduction in the context of the racial politics of the face and phenotype and the spatial politics of market expansion. While an 'infertility crisis' is often mentioned when explaining the growth of the assisted reproductive technologies (ARTs) industry, the use of donated reproductive cells is tied up in societal, ecological and economic shifts. Combining Software Studies analysis with Marxist Feminist and trans*feminist perspectives on shifting re/production dynamics, the article details the role of computational technologies in promoting certain ideas and beliefs about family and fixing certain territories of capital flow.

Social Categorization of Sexual Orientation via Verbal Cues: Evidence From a "Who Said What?" Study

Even though an abundant amount of research has demonstrated the ability to identify others' sexual orientation via minimal nonverbal cues, few studies, if any, have investigated the role of verbal information sources on the social cognition of sexual orientation. Herein, we aimed to explore whether verbal cues (gendered names) are adequate for triggering social categorization processes. Additionally, whether participant gender, target gender, and attributions toward homosexual targets differentiate sexual orientation-based categorization was examined. Our data showed that (1) participants categorized targets based on sexual orientation via semantic information, (2) female participants' categorization tendencies were marginally stronger than the males', and (3) negative attributions toward homosexual targets did not influence the categorization levels. Accordingly, the results contribute to the existing literature indicating the automatic detection of sexual orientation and clarify that perceivers not only use numerous nonverbal sources to extract categorical information about sexual orientation but also verbal cues.

Carving the Biodevelopment of Same-Sex Sexual Orientation at Its Joints

Sexual orientation is a core aspect of human experience and understanding its development is fundamental to psychology as a scientific discipline. Biological perspectives have played an important role in uncovering the processes that contribute to sexual orientation development. Research in this field has relied on a variety of populations, including community, clinical, and cross-cultural samples, and has commonly focused on female gynephilia (i.e., female sexual attraction to adult females) and male androphilia (i.e., male sexual attraction to adult males). Genetic, hormonal, and immunological processes all appear to influence sexual orientation. Consistent with biological perspectives, there are sexual orientation differences in brain development and evidence indicates that similar biological influences apply across cultures. An outstanding question in the field is whether the hypothesized biological influences are all part of the same process or represent different developmental pathways leading to same-sex sexual orientation. Some studies indicate that same-sex sexually oriented people can be divided into subgroups who likely experienced different biological influences. Consideration of gender expression in addition to sexual orientation might help delineate such subgroups. Thus, future research on the possible existence of such subgroups could prove to be valuable for uncovering the biological development of sexual orientation. Recommendations for such future research are discussed.

Accuracy and Consistency in Social Categorization Across Context, Motivation, and Time

Photos provide a literal snapshot of a person in a particular context at a specific moment in time. Previous studies have found that people can accurately categorize others from single photos of their faces along various social dimensions, yet this research typically assumes that one photo of an individual representatively samples other photos of the same individual. Across four studies, we investigated this assumption by testing the consistency of perceptions of social categories (viz. sexual orientation and political affiliation) based on multiple photos of the same individuals. We found that judgments of social categories exceeded chance and significantly correlated across different photo contexts, across variability in targets’ motivations, and across time. These data supplement earlier work showing similar consistency for other types of social judgments. Thus, single face photos can consistently convey some aspects of an individual's appearance.

A Crowdsourced Evaluation of Facial Averageness and Attractiveness

BACKGROUND

Evolutionary psychologists have demonstrated that humans are attracted to individuals who possess average anatomy for the population.

OBJECTIVES

The aim of this study was to prove that a composite of average facial features would be more attractive to raters than the cohort utilized to create the composite.

METHODS

The male and female cohorts each consisted of 41 standardized frontal-view monochrome photographs, with 1 composite image derived from the other 40 real images. Amazon Mechanical Turk, a widely used crowdsourcing platform, was utilized to obtain ratings of images ranging from 1 to 7, with 1 and 7 being least and most attractive, respectively. The strength of the preference for the composite over the real images was assessed by the difference between the mean rating of the composite and real images.

RESULTS

In total, 870 and 876 respondents were recruited to rate the male and female cohorts, respectively. For the male and female cohorts, the composite image was rated significantly higher than the rest of the cohort overall and across all ages, genders, and countries of residence (all P < 0.0001). For both cohorts, the strength of the preference was significantly higher for European respondents and lower for South American and nonbinary respondents (all P < 0.05).

CONCLUSIONS

This study reveals that average facial anatomy is perceived as most attractive across all demographics, a finding that is hoped to serve as a stepping stone for further studies leading to objective cosmetic quantifications and integrating evidence-based medicine into aesthetic surgery.

Fertility Status Does Not Facilitate Women's Judgment of Male Sexual Orientation

Previous research has demonstrated that women can correctly distinguish between gay and heterosexual men's faces significantly better than chance. This ability appears to be heightened during the most fertile portion of their ovulatory cycle. Here, we sought to replicate and extend these findings in a large sample of undergraduate women (N = 1960). Although women correctly identified men's sexual orientation significantly better than chance (62% average accuracy), a subsample of naturally cycling women (n = 426) did not judge men's sexual orientation from faces more accurately when in the fertile phase of their ovulatory cycle. These results further replicate the visibility of male sexual orientation, but do not show that this ability has strong links to estimated fertility.

To What Extent are Prenatal Androgens Involved in the Development of Male Homosexuality in Humans?

Endocrine variations, including possibly reduced exposure to androgens, may contribute to the development of male homosexuality, with animal models demonstrating same-sex mate preference with altered exposure during prenatal or early postnatal development. As similar studies in humans are impossible, indirect physical and cognitive measures of androgen exposure are used. Some studies suggest that physical measures affected by prenatal androgens, including the index-to-ring finger ratio, growth indices, and facial structure, are more "feminine" in gay men. Gay men also exhibit significant childhood gender non-conformity and a "feminized" anatomical and functional brain pattern in sexual arousal, as well as domains such as language, visuospatial skills and hemispheric relationships. However, many of these results are equivocal and may be confounded by other factors. Research has also been hampered by inconsistencies in the reporting of sexual orientation and the potentially unrepresentative populations of gay men studied, while additional complexities pertaining to gender conformity and sexual role may also influence results.

Mental rotation task performance in relation to sexual and gender diversity in Thailand

Neurohormonal theory argues that organizational effects of hormone exposure influence sexual orientation and gender identity, as well as sex differences in visuospatial cognition. This study examined mental rotation task (MRT) performance in a diverse Thai sample (N = 980). Thai culture has several third genders: individuals assigned male at birth (AMAB) who are feminine and attracted to cis men (i.e., sao praphet song); individuals assigned female at birth (AFAB) who are masculine and attracted to feminine individuals (i.e., toms); AFAB individuals who are feminine and attracted to toms (i.e., dees); and sexual orientation categories similar to Western culture (e.g., gay, lesbian, bi). On the MRT, straight cis men outperformed straight cis women. Results were consistent with organizational effects among AMAB individuals, with straight cis men outperforming gay cis men and sao praphet song. Among AFAB individuals, however, only bi and lesbian cis women outperformed dees. Overall, support for neurohormonal theory was limited among AFAB individuals, but MRT performance among AMAB individuals was consistent with organizational effects. This study informs our understanding of visuospatial sex/gender differences and the applicability of neurohormonal theory across cultures.

Facial structure and perception of sexual orientation: Research with face models based on photographs of real people

Some evidence suggests that lay persons are able to perceive sexual orientation from face stimuli above the chance level. A morphometric study of 390 heterosexual and homosexual Canadian people of both sexes reported that facial structure differed depending on the sexual orientation. Gay and heterosexual men differed on three metrics as the most robust multivariate predictors, and lesbian and heterosexual women differed on four metrics. A later study verified the perceptual validity of these multivariate predictors using artificial three-dimensional face models created by manipulating the key parameters. Nevertheless, there is evidence of important processing differences between the perception of real faces and the perception of artificial computer-generated faces. The present study which composed of two experiments tested the robustness of the previous findings and extended the research by experimentally manipulating the facial features in face models created from photographs of real people. Participants of the Experiment 1 achieved an overall accuracy (0.67) significantly above the chance level (0.50) in a binary hetero/homosexual judgement task, with some important differences between male and female judgements. On the other hand, results of the Experiment 2 showed that participants rated the apparent sexual orientation of series of face models created from natural photographs as a continuous linear function of the multivariate predictors. Theoretical implications are discussed.

Speech Acoustic Features: A Comparison of Gay Men, Heterosexual Men, and Heterosexual Women

Potential differences between homosexual and heterosexual men have been studied on a diverse set of social and biological traits. Regarding acoustic features of speech, researchers have hypothesized a feminization of such characteristics in homosexual men, but previous investigations have so far produced mixed results. Moreover, most studies have been conducted with English-speaking populations, which calls for further cross-linguistic examinations. Lastly, no studies investigated so far the potential role of testosterone in the association between sexual orientation and speech acoustic features. To fill these gaps, we explored potential differences in acoustic features of speech between homosexual and heterosexual native French men and investigated whether the former showed a trend toward feminization by comparing theirs to that of heterosexual native French women. Lastly, we examined whether testosterone levels mediated the association between speech acoustic features and sexual orientation. We studied four sexually dimorphic acoustic features relevant for the qualification of feminine versus masculine voices: the fundamental frequency, its modulation, and two understudied acoustic features of speech, the harmonics-to-noise ratio (a proxy of vocal breathiness) and the jitter (a proxy of vocal roughness). Results showed that homosexual men displayed significantly higher pitch modulation patterns and less breathy voices compared to heterosexual men, with values shifted toward those of heterosexual women. Lastly, testosterone levels did not influence any of the investigated acoustic features. Combined with the literature conducted in other languages, our findings bring new support for the feminization hypothesis and suggest that the feminization of some acoustic features could be shared across languages.

Emotion and Gender Typicality Cue Sexual Orientation Differently in Women and Men

Heterosexual individuals tend to look and act more typical for their gender compared to gay and lesbian individuals, and people use this information to infer sexual orientation. Consistent with stereotypes associating happy expressions with femininity, previous work found that gay men displayed more happiness than straight men-a difference that perceivers used, independent of gender typicality, to judge sexual orientation. Here, we extended this to judgments of women's sexual orientation. Like the gender-inversion stereotypes applied to men, participants perceived women's faces manipulated to look angry as more likely to be lesbians; however, emotional expressions largely did not distinguish the faces of actual lesbian and straight women. Compared to men's faces, women's faces varied less in their emotional expression (appearing invariably positive) but varied more in gender typicality. These differences align with gender role expectations requiring the expression of positive emotion by women and prohibiting the expression of femininity by men. More important, greater variance within gender typicality and emotion facilitates their respective utility for distinguishing sexual orientation from facial appearance. These findings thus provide the first evidence for contrasting cues to women's and men's sexual orientation and suggest that gender norms may uniquely shape how men and women reveal their sexual orientation.

Gender identity, sexual orientation and adverse sexual experiences in autistic females

BACKGROUND

There is growing recognition that autistic females present with more diverse gender and sexual identities than their non-autistic counterparts. Likewise, autistic females are also at an increased risk of adverse sexual experiences. As higher rates of sexual victimisation are observed in individuals with diverse sexual identities in the broader population, rates of negative sexual experiences among autistic females remain unclear. This study aimed to investigate the representation of gender and sexual diversity within autistic females and examine their rates of regretted, and unwanted, sexual encounters among females with a transgender gender identity and non-heterosexual sexual orientation.

METHODS

Two hundred and ninety-five females completed the Sexual Behaviour Scale-III (SBS-III) online. Self-reported gender identity and sexual orientation were compared between 134 autistic (M_age= 26.2 years, SD = 8.7) and 161 non-autistic females (M_age = 22.0 years, SD = 4.6). Differences in the prevalence of negative sexual experiences were compared across diagnosis and each gender identity and sexual orientation label.

RESULTS

Autistic females were more likely to identify with a transgender gender identity (p < .05) and non-heterosexual sexual orientation (p < .007) compared to non-autistic females. Autistic homosexual females were more likely to have experienced a range of negative sexual experiences than autistic heterosexual females (OR ≥ 3.29; p < .01) and were more likely to have experienced unwanted sexual experiences than non-autistic females regardless of sexual orientation (OR ≥ 2.38; p < .05). There were no differences in rates of negative sexual experiences between autistic bisexual and both autistic heterosexual and non-autistic bisexual females. Non-autistic bisexual females (OR = 0.24; p = .018) presented with a reduced risk of regretted sexual experiences than non-autistic heterosexual peers. There were no differences in negative sexual experiences across gender identity in the autistic sample.

LIMITATIONS

The use of fixed format response items may have restricted participants' abilities to provide rich responses pertaining to their sexual identities and nature of negative sexual experiences. The small number of participants who identified as transgender (n = 40) limits the reliability of results pertaining to sexual experiences across gender identity. Moreover, although multiple recruitment methods were used in this study, non-representative may bias estimates of prevalence rates. Thus, the data may not be representative of the broader population.

CONCLUSIONS

Results indicate that autistic females present with greater diversity in their sexual identities than individuals without autism, with those with a homosexual sexual orientation being at greater risk of experiencing adverse sexual encounters. Findings suggest the importance of increased clinical attention to this diversity and the need to provide support to facilitate the development of a healthy sexual identity and reduce the risks identified in this study.

A short review of biological research on the development of sexual orientation

We review research supporting biological mechanisms in the development of sexual orientation. This research includes studies on neural correlates, prenatal hormones and related physical/behavioral correlates, genetics, and the fraternal birth order effect (FBOE). These studies, taken together, have provided substantial support for biological influences underlying the development of sexual orientation, but questions remain unanswered, including how biological mechanisms may differ in contributing to men's and women's sexual orientation development.

Offspring Production Among the Relatives of Istmo Zapotec Men and Muxes

Male androphilia (i.e., sexual attraction toward adult males) is influenced by biological factors, reliably occurs across diverse cultures, and has persisted over evolutionary time despite the fact that it reduces reproduction. One possible solution to this evolutionary paradox is the sexually antagonistic gene hypothesis (SAGH), which states that genes associated with male androphilia reduce reproduction when present in males but increase reproduction when present in their female relatives. The present study tested the SAGH among the Istmo Zapotec-a non-Euro-American culture in Oaxaca, Mexico, where transgender and cisgender androphilic males are known as muxe gunaa and muxe nguiiu, respectively. To test the SAGH, we compared offspring production by the biological relatives of muxe gunaa (n = 115), muxe nguiiu (n = 112), and gynephilic men (i.e., cisgender males who are sexually attracted to adult females; n = 171). The mothers and paternal aunts of muxe gunaa had higher offspring production than those of muxe nguiiu. Additionally, the relatives of muxe gunaa had more offspring than those of gynephilic men, whereas no such differences were found between the families of gynephilic men and muxe nguiiu. Elevated reproduction by the mothers and, particularly the aunts, of muxe gunaa is consistent with the SAGH. However, the absence of group differences between gynephilic men and muxe nguiiu, and the group differences between the two types of muxes are not predicted by the SAGH. This is the first study to demonstrate reproductive differences between kin of transgender and cisgender androphilic males within the same non-Euro-American culture.

Fraternal Birth Order, Only-Child Status, and Sibling Sex Ratio Related to Sexual Orientation in the Add Health Data: A Re-analysis and Extended Findings

The fraternal birth order (FBO) effect related to men's sexual orientation refers to the finding that the number of older brothers that a man has increases his chance of being androphilic. The FBO effect has generally been well replicated in diverse samples; one instance of non-replication was by Francis (2008) using Waves I and III of the Add Health data. We attempted to replicate the FBO effect in the Add Health data taking into account family size and other limitations of Francis' (2008) analyses. Also, we examined other sibling characteristics related to the FBO effect: sibling sex ratio and only-child status. We used two subsamples from Waves I (n = 20,745) and IV (n = 15,701) of the Add Health data, consisting of adolescents who were followed longitudinally from 1994 to 1995 until 2008. Wave I data were used to compute numbers of younger and older brothers and sisters from household roster information. Wave IV information about sexual orientation identity was used. Analyses were conducted within men and within women. We found modest support for the FBO effect in men, but not in women, using the older brother odds ratio, logistic regression analyses, and sibling sex ratio, which provided the strongest support for FBO. We found that gynephilic/biphilic women, but not androphilic/biphilic men, were more likely to be only-children compared to androphilic women and gynephilic men, respectively. We discuss limitations of the Add Health data and purported mechanisms for the FBO effect in men and the only-child effect in women.

A Leader Doesn’t Sound Lesbian!: The Impact of Sexual Orientation Vocal Cues on Heterosexual Persons’ First Impression and Hiring Decision

In three studies ( N = 340), we tested whether vocal cues to a person’s sexual orientation prompted sexual orientation discrimination in heterosexual individuals when hiring leaders. Our results inform how gender and sexual orientation intersect to produce discriminatory effects in the hiring context. Heterosexual participants listened to short clips of voices that sounded like job candidate was a lesbian or heterosexual woman, or a gay or heterosexual man, and rated all for job suitability and employability. Candidates applied for jobs as leaders (Study 1), as leaders or assistants (Study 2), and for leadership roles that varied in both gender role and status (Study 3). Sexual orientation discrimination occurred in all three studies and was greater among women job candidates. Refuting role congruity theory, several findings disconfirmed the prediction that lesbian-sounding women would be advantaged when stereotyped as masculine and when applying for leadership roles. Rather, in line with status-beliefs theory, lesbian-sounding women and gay-sounding men were rated and ranked poorly to the extent that they were perceived as less competent than heterosexual candidates. Findings suggest that hiring discrimination occurs in subtle ways, such as when individuals sound gay/lesbian. This has implications for recruitment as well as sexual-orientation discrimination court cases. Online slides for instructors who want to use this article for teaching are available on PWQ's website at http://journals.sagepub.com/doi/suppl/10.1177/0361684319891168

The biological basis of sexual orientation: How hormonal, genetic, and environmental factors influence to whom we are sexually attracted

Humans develop relatively stable attractions to sexual partners during maturation and present a spectrum of sexual orientation from homosexuality to heterosexuality encompassing varying degrees of bisexuality, with some individuals also displaying asexuality. Sexual orientation represents a basic life phenomenon for humans. However, the molecular mechanisms underlying these diverse traits of sexual orientation remain highly controversial. In this review, we systematically discuss recent advancements in sexual orientation research, including those related to measurements and associated brain regions. Current findings regarding sexual orientation modulation by hormonal, genetic, maternal immune system, and environmental factors are summarized in both human and model systems. We also emphasize that future studies should recognize the differences between males and females and pay more attention to minor traits and the epigenetic regulation of sexual orientation. A comprehensive view of sexual orientation may promote our understanding of the biological basis of sex, and that of human reproduction, and evolution.

Male Homosexual Preference: Femininity and the Older Brother Effect in Indonesia

Male homosexual preference (MHP) is an evolutionary enigma because it is partially heritable and imposes a fertility cost. In occidental societies, homosexual men are feminized at various levels and they have more older brothers than heterosexual men. To evaluate whether femininity and the fraternal birth order (FBO) effect are universal features of MHP or not, we collected original data from homosexual men, heterosexual men, and heterosexual women from Java (Indonesia). Facial photographs were used to test whether homosexual faces are feminized when compared with heterosexual ones. We found that faces manipulated to resemble the average face of homosexual men are perceived as facially feminized, suggesting that homosexual men are facially feminized compared to heterosexual men, although a higher facial femininity was not captured by morphological analyses. Then, family data were used to detect differences in siblings' composition between homosexuals and heterosexuals. Homosexual men displayed a higher number of older brothers than heterosexual men, even when sibship size was controlled for, suggesting that the FBO effect exists in Indonesian populations. Independent of sexual orientation, men with older brothers seem more feminized than those without older brothers, consistent with the immune origin of the FBO effect. In conclusion, MHP in Indonesia is partially feminized and they have more older brothers. Such features are also associated with MHP in other cultural contexts, suggesting a cross-cultural effect of men homosexual preference. An evolutionary explanation is available for the feminizing effect, although the FBO effect remains unexplained even if proximal mechanisms start to be identified.

A Life History Approach to the Female Sexual Orientation Spectrum: Evolution, Development, Causal Mechanisms, and Health

Women's capacity for sexual fluidity is at least as interesting a phenomenon from the point of view of evolutionary biology and behavioral endocrinology as exclusively homosexual orientation. Evolutionary hypotheses for female nonheterosexuality have failed to fully account for the existence of these different categories of nonheterosexual women, while also overlooking broader data on the causal mechanisms, physiology, ontogeny, and phylogeny of female nonheterosexuality. We review the evolutionary-developmental origins of various phenotypes in the female sexual orientation spectrum using the synergistic approach of Tinbergen's four questions. We also present femme-specific and butch-specific hypotheses at proximate and ultimate levels of analysis. This review article indicates that various nonheterosexual female phenotypes emerge from and contribute to hormonally mediated fast life history strategies. Life history theory provides a biobehavioral explanatory framework for nonheterosexual women's masculinized body morphology, psychological dispositions, and their elevated likelihood of experiencing violence, substance use, obesity, teenage pregnancy, and lower general health. This pattern of life outcomes can create a feedback loop of environmental unpredictability and harshness which destabilizes intrauterine hormonal conditions in mothers, leading to a greater likelihood of fast life history strategies, global health problems, and nonheterosexual preferences in female offspring. We further explore the potential of female nonheterosexuality to function as an alloparental buffer that enables masculinizing alleles to execute their characteristic fast life history strategies as they appear in the female and the male phenotype. Synthesizing life history theory with the female sexual orientation spectrum enriches existing scientific knowledge on the evolutionary-developmental mechanisms of human sex differences.

Facial recognition from DNA using face-to-DNA classifiers

Facial recognition from DNA refers to the identification or verification of unidentified biological material against facial images with known identity. One approach to establish the identity of unidentified biological material is to predict the face from DNA, and subsequently to match against facial images. However, DNA phenotyping of the human face remains challenging. Here, another proof of concept to biometric authentication is established by using multiple face-to-DNA classifiers, each classifying given faces by a DNA-encoded aspect (sex, genomic background, individual genetic loci), or by a DNA-inferred aspect (BMI, age). Face-to-DNA classifiers on distinct DNA aspects are fused into one matching score for any given face against DNA. In a globally diverse, and subsequently in a homogeneous cohort, we demonstrate preliminary, but substantial true (83%, 80%) over false (17%, 20%) matching in verification mode. Consequences of future efforts include forensic applications, necessitating careful consideration of ethical and legal implications for privacy in genomic databases.

Nonverbal Communication

The field of nonverbal communication (NVC) has a long history involving many cue modalities, including face, voice, body, touch, and interpersonal space; different levels of analysis, including normative, group, and individual differences; and many substantive themes that cross from psychology into other disciplines. In this review, we focus on NVC as it pertains to individuals and social interaction. We concentrate specifically on ( a) the meanings and correlates of cues that are enacted (sent) by encoders and ( b) the perception of nonverbal cues and the accuracy of such perception. Frameworks are presented for conceptualizing and understanding the process of sending and receiving nonverbal cues. Measurement issues are discussed, and theoretical issues and new developments are covered briefly. Although our review is primarily oriented within social and personality psychology, the interdisciplinary nature of NVC is evident in the growing body of research on NVC across many areas of scientific inquiry.

The Facial Width-to-Height Ratio Predicts Sex Drive, Sociosexuality, and Intended Infidelity

Previous research has linked the facial width-to-height ratio (FWHR) to a host of psychological and behavioral characteristics, primarily in men. In two studies, we examined novel links between FWHR and sex drive. In Study 1, a sample of 145 undergraduate students revealed that FWHR positively predicted sex drive. There were no significant FWHR × sex interactions, suggesting that FWHR is linked to sexuality among both men and women. Study 2 replicated and extended these findings in a sample of 314 students collected from a different Canadian city, which again demonstrated links between the FWHR and sex drive (also in both men and women), as well as sociosexuality and intended infidelity (men only). Internal meta-analytic results confirm the link between FWHR and sex drive among both men and women. These results suggest that FWHR may be an important morphological index of human sexuality.

Cross-Cultural Evidence for Apparent Racial Outgroup Advantage: Congruence between Perceived Facial Aggressiveness and Fighting Success

Research into face processing consistently shows an outgroup disadvantage in areas such as recognition memory and emotional identification. Potential ingroup advantage with respect to inferences regarding personality and behavioural outcomes, on the other hand, has not yet been studied. In the present study, we used the faces of male professional mixed martial arts (MMA) fighters of apparent African, European, or mixed-race origin as targets and males from four distant populations that vary in ethnic composition as perceivers. We compared the perceivers’ inferences about targets’ aggressiveness with the fighters’ actual performance in professional MMA championships. Surprisingly, across three distant populations used in the study (Cameroon, Czech Republic, and Turkey), perceivers’ inferences based on face rating were more congruent with real-world performance for targets belonging to an apparent racial outgroup (as opposed to ingroup). In an ethnically mixed population (Brazil), perceivers showed the lowest congruence for apparently mixed-race targets. It thus seems that the outgroup disadvantage observed in other face processing domains does not carry over to inferences about aggressive behavioural outcomes. In fact, it seems that this relationship is, if anything, reversed.

Aesthetic as genetic: The epistemological violence of gaydar research

In recent years, “gaydar” has come under increasing scientific scrutiny. Gaydar researchers have found that we can accurately judge sexual orientation at better than chance levels from various nonverbal cues. Why they could find what they did is typically chalked up to gender inverted phenotypic variations in craniofacial structure that distinguish homosexuals. This interpretation of gaydar data (the “hegemonic interpretation”) maintains a construction of homosexuality as both a “natural kind” and an “entitative” category. As a result, culturally and historically contingent markers of homosexuality are naturalized under the guise of gaydar. Of significant relevance to this article’s critique of gaydar research is that the hegemonic interpretation is presented as politically advantageous for LGB people by its authors, an undertheorized assumption that risks sanctioning an epistemological violence with unfortunate, demobilizing sociopolitical consequences. This critique is contextualized within current debates regarding intimate/sexual citizenship and advocates, instead, for a queer political ethic that considers such cultural erasure to be politically untenable.

Evidence for the Absence of Stimulus Quality Differences in Tests of the Accuracy of Sexual Orientation Judgments: A Reply to Cox, Devine, Bischmann, and Hyde (2016)

An article recently published in this journal (Cox, Devine, Bischmann, & Hyde, 2016) questioned the validity of existing research on the accurate judgment of sexual orientation from photographs of faces. Specifically, those authors reported a confound in their stimuli whereby the photos of sexual minorities (gay men and lesbians) were of higher quality than the photos of heterosexuals. Based on this finding, they concluded that the accuracy in judging sexual orientation from faces demonstrated in the broader literature is an artifact of stimulus quality differences. Here, we addressed this claim by systematically testing the numerous photo sets that we have used in 61 studies documenting accurate judgments of sexual orientation from facial cues published since 2007. Contrary to their claim, the overwhelming majority of studies (93%) showed no significant differences in photo quality according to sexual orientation. Of those that did show differences, most revealed that heterosexual targets' photos were actually of higher quality than sexual minority targets' photos - opposite of what Cox et al. found. In addition, we highlight additional research using stimuli equated for quality differences overlooked in the recent article by Cox et al., lending further support to the conclusion that sexual orientation is legible from multiple sensory cues.

Perception of Sexual Orientation from Facial Structure: A Study with Artificial Face Models

Research has shown that lay people can perceive sexual orientation better than chance from face stimuli. However, the relation between facial structure and sexual orientation has been scarcely examined. Recently, an extensive morphometric study on a large sample of Canadian people (Skorska, Geniole, Vrysen, McCormick, & Bogaert, 2015) identified three (in men) and four (in women) facial features as unique multivariate predictors of sexual orientation in each sex group. The present study tested the perceptual validity of these facial traits with two experiments based on realistic artificial 3D face models created by manipulating the key parameters and presented to Spanish participants. Experiment 1 included 200 White and Black face models of both sexes. The results showed an overall accuracy (0.74) clearly above chance in a binary hetero/homosexual judgment task and significant differences depending on the race and sex of the face models. Experiment 2 produced five versions of 24 artificial faces of both sexes varying the key parameters in equal steps, and participants had to rate on a 1-7 scale how likely they thought that the depicted person had a homosexual sexual orientation. Rating scores displayed an almost perfect linear regression as a function of the parameter steps. In summary, both experiments demonstrated the perceptual validity of the seven multivariate predictors identified by Skorska et al. and open up new avenues for further research on this issue with artificial face models.

Internalized Homophobia Influences Perceptions of Men's Sexual Orientation from Photos of Their Faces

Although researchers have explored the perceiver characteristics that make people accurate at identifying others' sexual orientations, characteristics of the targets remain largely unexplored. In the current study, we examined how individual differences in internalized homophobia among gay men can affect perceptions of their sexual orientation by asking 49 individuals to judge the sexual orientations of 78 gay men from photos of their faces. We found that gay men reporting higher levels of internalized homophobia were less likely to have come out of the closet and were, in turn, less likely to be perceived as gay. Thus, internalized homophobia and the concealment of one's sexual minority status can impact perceptions of sexual orientation.

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

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.

Pubertal Stress and Nutrition and their Association with Sexual Orientation and Height in the Add Health Data

A number of studies have indicated that gay men tend to be shorter, on average, than heterosexual men. Less evidence exists that lesbian women are taller, on average, than heterosexual women. The most popular explanation of the association between sexual orientation and height involves prenatal factors, such that, for example, gay men may have been exposed to lower than typical androgens during fetal development, which impacts their height and sexual orientation as adults. An alternative explanation involves stress, given that stress has been associated with sexual minority identification and with lower height. Another alternative explanation involves nutrition, although its relationship is less clear with sexual minority identification. Using the Add Health data, which is a large, nationally representative and longitudinal sample of American adolescents (n = 14,786), we tested a mediation model, such that sexual orientation → pubertal stress/nutrition → height. Within men, we found that gay men (n = 126) were shorter, on average, than heterosexual men (n = 6412). None of the 24 pubertal stress-related and 15 pubertal nutrition-related variables assessed in the Add Health data mediated the relationship between sexual orientation and height in men. Within women, lesbians (n = 75) did not differ significantly in stature compared to heterosexual women (n = 6267). Thus, prenatal mechanisms (e.g., hormones, maternal immune response) are likely better candidates for explaining the height difference between gay men and heterosexual men.

Sexual Orientation, Objective Height, and Self-Reported Height

Studies that have used mostly self-reported height have found that androphilic men and women are shorter than gynephilic men and women, respectively. This study examined whether an objective height difference exists or whether a psychosocial account (e.g., distortion of self-reports) may explain these putative height differences. A total of 863 participants, recruited at a Canadian university, the surrounding region, and through lesbian, gay, bisexual, and transgender (LGBT) events across Canada, self-reported their height and had their height measured. Androphilic men were shorter, on average, than gynephilic men. There was no objective height difference between gynephilic, ambiphilic, and androphilic women. Self-reported height, statistically controlling for objective height, was not related to sexual orientation. These findings are the first to show an objective height difference between androphilic and gynephilic men. Also, the findings suggest that previous studies using self-reported height found part of a true objective height difference between androphilic and gynephilic men. These findings have implications for existing biological theories of men's sexual orientation development.

Perceptions of Sexual Orientation From Minimal Cues

People derive considerable amounts of information about each other from minimal nonverbal cues. Apart from characteristics typically regarded as obvious when encountering another person (e.g., age, race, and sex), perceivers can identify many other qualities about a person that are typically rather subtle. One such feature is sexual orientation. Here, I review the literature documenting the accurate perception of sexual orientation from nonverbal cues related to one's adornment, acoustics, actions, and appearance. In addition to chronicling studies that have demonstrated how people express and extract sexual orientation in each of these domains, I discuss some of the basic cognitive and perceptual processes that support these judgments, including how cues to sexual orientation manifest in behavioral (e.g., clothing choices) and structural (e.g., facial morphology) signals. Finally, I attend to boundary conditions in the accurate perception of sexual orientation, such as the states, traits, and group memberships that moderate individuals' ability to reliably decipher others' sexual orientation.

“Gaydar”

Though many of people’s impressions about each other stem from qualities that are obvious or apparent, social perceptions also rely on a variety of subtle cues that guide judgment and behavior. For example, emerging work has increasingly elucidated the conditions and means by which individuals’ accuracy in judging others’ sexual orientation is better than chance. We discuss these here, focusing on four domains from which people draw cues to accurately perceive sexual orientation: how people adorn themselves (adornment), how they move (actions), how they sound (acoustics), and how they look (appearance). Moreover, we describe how certain factors, such as one’s own sexual orientation, can constrain or facilitate this accuracy and describe the various negative social and occupational consequences that may result from cues that someone is gay or straight.

Is Gaydar Affected by Attitudes Toward Homosexuality? Confidence, Labeling Bias, and Accuracy

Previous research has largely ignored the relationship between sexual orientation judgement accuracy, confidence, and attitudes toward homosexuality. In an online study, participants (N = 269) judged the sexual orientation of homosexual and heterosexual targets presented via a series of facial photographs. Participants also indicated their confidence in each judgment and completed the Modern Homonegativity Scale (Morrison & Morrison, 2002). We found that (1) homosexual men and heterosexual women were more accurate when judging photographs of women as opposed to photographs of men, and (2) in heterosexual men, negative attitudes toward homosexual men predicted confidence and bias when rating men's photographs. Findings indicate that homosexual men and heterosexual women are similar in terms of accuracy in judging women's sexuality. Further, especially in men, homophobia is associated with cognitive biases in labeling other men but does not have a relationship with increased accuracy.

People Use Psychological Cues to Detect Physical Disease From Faces

Previous theoretical work has suggested that people can accurately perceive disease from others' appearances and behaviors. However, much of that research has examined diseases with relatively obvious symptoms (e.g., scars, obesity, blemishes, sneezing). Here, we examined whether people similarly detect diseases that do not exhibit such visible physical cues (i.e., sexually transmitted diseases). We found that people could indeed identify individuals infected with sexually transmitted diseases significantly better than chance from photos of their faces. Perceptions of the targets' affective expression and socioeconomic status mediated participants' accuracy. Finally, increasing participants' contamination fears improved their sensitivity to disease cues. These data therefore suggest that people may use subtle and indirect psychological markers to detect some physical diseases from appearance.

Age-Related Physical Changes Interfere With Judgments of Male Sexual Orientation From Faces

Although studies have shown that sexual orientation can be judged from faces, this research has not considered how age-related differences in perceivers or targets affect such judgments. In the current work, we evaluated whether accuracy differed among young adults (YA) and older adults (OA) for young and old men's faces by recruiting a sample of YA and OA in the lab, a community sample of sexual minority men, and a sample of online participants. We found that OA and YA judged sexual orientation with similar accuracy. Perceptions of gender atypicality mediated the difference in judging older and younger targets' sexual orientation. Although participants used positive affect to correctly discern sexual orientation regardless of target age, perceptions of masculinity were valid only for judgments of YA.