The Subtlety of Sex-Atypicality

Memories of sex-atypical behavior and interests in childhood usually differ between homosexual and heterosexual people. However, variation within these broad groups has not previously been explored in detail, especially among women. We utilized data from a postal survey of a nationwide sample of Australian adult twins (n = 4,901, age range: 19–52 years). Among men, 15.2% reported homosexual behavior (ever), 11.5% said they had been sexually attracted to the same sex, and 6.4% said they were not heterosexual; the corresponding figures for women were 7.9, 10.6, and 3.5%. A continuous measure of childhood gender nonconformity (CGN) was sensitive to slight variations in homosexual attraction and behavior. In particular, among both men and women who identified as heterosexual, there were significant differences between complete heterosexuals and those who admitted to only one or a few same-sex behaviors but no homosexual attraction. Among men, CGN scores distinguished between heterosexuals who admitted to same-sex behavior only and those who admitted to some homosexual attraction. The sexual subgroups also differed on a measure of gender atypicality in adulthood. Implications for developmental theories of sexuality are discussed.     

Homosexual Mating Preferences from an Evolutionary Perspective: Sexual Selection Theory Revisited

Studies in evolutionary psychology and sexual selection theory show that heterosexual men prefer younger mating partners than heterosexual women in order to ensure reproductive success. However, previous research has generally not examined differences in mating preferences as a function of sexual orientation or the type of relationship sought in naturalistic settings. Given that homosexual men seek partners for reasons other than procreation, they may exhibit different mating preferences than their heterosexual counterparts. Moreover, mating preferences may show important differences depending on whether an individual is seeking a long-term versus a short-term relationship. The purpose of the present study was to examine these issues by comparing partner preferences in terms of age and relationship type between homosexual and heterosexual men placing internet personal advertisements. Participants included 439 homosexual and 365 heterosexual men who placed internet ads in the U.S. or Canada. Ads were coded for the participant’s age, relationship type (longer-term or short-term sexual encounter) sought, and partner age preferences. Significantly more homosexual than heterosexual men sought sexual encounters, although men (regardless of sexual orientation) seeking sexual encounters preferred a significantly wider age range of partners than men seeking longer-term relationships. These findings suggest that partner preferences are independent of evolutionary drives to procreate, since both types of men preferred similar ages in their partners. In addition, they highlight the importance of examining relationship type in evolutionary studies of mating preferences, as men’s partner preferences show important differences depending upon the type of relationship sought.     

Self-Reported Sexual Desire in Homosexual Men and Women Predicts Preferences for Sexually Dimorphic Facial Cues

Recent studies investigating the relationship between self-reported sexual desire and attraction to same- and opposite-sex individuals have found that homosexual men’s sexual desire is positively correlated with their self-reported attraction to own-sex individuals only, while homosexual women’s sexual desire is positively correlated with their self-reported attraction to both men and women. These data have been interpreted as evidence that sexual desire strengthens men’s pre-existing (i.e., dominant) sexual behaviors and strengthens women’s sexual behaviors in general. Here we show that homosexual men’s (n = 106) scores on the Sexual Desire Inventory-2 (SDI-2) were positively correlated with their preferences for exaggerated sex-typical shape cues in own-sex, but not opposite-sex, faces. Contrary to the hypothesis that sexual desire strengthens women’s preferences for sexual dimorphism generally, homosexual women’s (n = 83) SDI-2 scores were positively correlated with their preferences for exaggerated sex-typical shape cues in opposite-sex faces only. Together with previous research in heterosexual subjects, our findings support the proposal that sexual desire increases the incidence of existing sexual behaviors in homosexual and heterosexual men, and increases the incidence of sexual responses more generally in heterosexual women, although not necessarily in homosexual women.     

Sexual stigma and sympathy: attitudes toward persons living with HIV in Jamaica

As the number of persons living with HIV continues to increase in Jamaica, attitudes and values become more important. This study aimed to examine the attitudes of university students in Jamaica toward persons living with HIV, including homosexual men, heterosexual men, women sex workers, other women, and children. One thousand two hundred and fifty-two students were surveyed between June 2001 and February 2002 using a 193-item questionnaire measuring a variety of HIV-related knowledge, attitudinal and behavioural items. Less than half of students reported sympathetic attitudes toward homosexual men or women sex workers living with HIV while a majority reported generally sympathetic attitudes toward heterosexual men and non-sex worker women living with the disease. Predictors of sympathy varied by target group. Male students were significantly less likely to report sympathy for homosexual men than for any other group. Spirituality was associated with sympathy for homosexual men and women sex workers, but not for the remaining two groups. Findings suggest that levels of negative attitudes are high in Jamaica and warrant attention to both individual and societal-level actions and interventions. In addition, messages and interventions must be targeted, recognizing both the differences in level of sympathy expressed toward different groups and predictors of sympathy across the groups.     

Same-sex sexuality and quality of life: findings from the Netherlands Mental Health Survey and Incidence Study

This study assessed differences in quality of life (QL) between homosexual and heterosexual people and attempted to identify factors accounting for observed differences. Data were collected in a representative sample of the Dutch population aged 18–64 (N = 7,076). Classification as heterosexual or homosexual was based upon reported sexual behavior in the preceding year; 84.8% of the total sample (N = 5,998) could be classified: 2.8% of 2,878 sexually active men and 1.4% of 3,120 sexually active women had had same-sex partners. Differences in QL were tested by analysis of variance. Factors accounting for observed differences in QL were identified by selecting determinants of QL on which homosexual and heterosexual people differed and including them with same-sex sexuality in multiple regression analyses. Homosexual men, but not women, differed from their heterosexual counterparts on various dimensions of QL. Lesser QL in homosexual men was predominantly explained by self-esteem and mastery. Same-sex sexuality contributed independently to some of the observed differences. Although same-sex sexuality is related to QL in men, the lack of association in women suggests that the link is mediated by other factors, indicating the need to explore in what respect the situation of homosexual men and women differs. This study also suggests the importance of finding out how lower sense of self-esteem and of mastery come about in homosexual men.     

Do homosexual persons use health care services more frequently than heterosexual persons: findings from a Dutch population survey

Use of health care services has been suggested to be lower among homo- or bisexual persons than among heterosexual persons, due to a lack of trust in the health care system. However, population-based studies on differences in health care utilization according to sexual orientation are scarce. The purpose of the current study was to explore differences in health care utilization and confidence in health care between heterosexual, bisexual and homosexual persons. A survey of a random sample of patients of Dutch general practices (n = 9684) gathered data on socio-demographic variables, sexual orientation, health status, confidence in health care and health care utilization. Differences in health care utilization between homo- or bisexual persons and heterosexual persons were analyzed with logistic regression analysis, in which we statistically adjusted for socio-demographics and health status. Reported health was lower among homosexual men and women as compared to heterosexual persons. There were no sexual orientation-related differences in confidence in health care. Controlling for health status, it appeared that gay men more frequently used mental and somatic health care than heterosexual men, and that lesbian or bisexual women more frequently used mental health care than heterosexual women. We found a higher rate of health care use among homosexual and bisexual persons as compared to heterosexual persons, that could only be partly explained by differences in health status. To gain a better understanding of our findings, data on the predisposition to use health services among homosexual and bisexual men and women is needed.     

Sexual Orientation Differences in Cerebral Asymmetry and in the Performance of Sexually Dimorphic Cognitive and Motor Tasks

With each of the tasks in the present studies we expected to find the reported sex difference between heterosexual women and heterosexual men and we predicted a sexual orientation effect with the performance of homosexual men being similar to that of heterosexual women and different from that of heterosexual men. Study I aimed to replicate earlier findings by recording the performance of a group of homosexual men on a visuospatial task, the Vincent Mechanical Diagrams Test (VMDT), a dot detection divided visual field measure of functional cerebral asymmetry, and on five subtests of the Wechsler Adult Intelligence Scale (WAIS). For each task the profile of scores obtained for the homosexual men was similar to that of heterosexual women in that they scored lower than heterosexual men on the VMDT, they showed less asymmetry, and they recorded a higher Verbal than Performance IQ on the WAIS. In Study 2, a male-biased targeted throwing task favored heterosexual men while, in contrast, on the female-biased Purdue Pegboard single peg condition heterosexual men were outperformed by heterosexual women and homosexual men. On neither of these two tasks did the performances of homosexual men and heterosexual women differ. One task, manual speed, yielded neither sex nor sexual orientation differences. Another, the Purdue Pegboard assemblies condition, revealed a sex difference but no sexual orientation difference. Failure to obtain a sexual orientation difference in the presence of a sex difference suggests that the sexual orientation effect may be restricted to a subset of sexually dimorphic tasks.     

Suicidality and Sexual Orientation: Differences Between Men and Women in a General Population-Based Sample From The Netherlands

Homosexuality has been shown to be associated with suicidality and mental disorders. It is unclear whether homosexuality is related to suicidality, independently of mental disorders. This study assessed differences in lifetime symptoms of suicidality (death ideation, death wishes, suicide contemplation, and deliberate self-harm) between homosexual and heterosexual men and women, controlling for lifetime psychiatric morbidity. Interaction effects of age and the role of perceived discrimination were also examined. Data were collected on a representative sample of the Dutch population aged 18–64 years. Classification as heterosexual or homosexual was based upon reported sexual behavior in the preceding year. Of those sexually active, 2.8% of 2,878 men and 1.4% of 3,120 women had had same-sex partners. Homosexual men differed from their heterosexual counterparts on all four suicide symptoms (OR ranging from 2.58 to 10.23, with higher ORs for more severe symptoms), and on the sum total of the four symptoms; homosexual women only differed from heterosexual women on suicide contemplation (OR=2.12). Controlling for psychiatric morbidity decreased the ORs, but among men all associations were still significant; the significance for suicide contemplation among women disappeared. Younger homosexuals were not at lower risk for suicidality than older homosexuals in comparison with their heterosexual counterparts. Among homosexual men, perceived discrimination was associated with suicidality. This study suggests that even in a country with a comparatively tolerant climate regarding homosexuality, homosexual men were at much higher risk for suicidality than heterosexual men. This relationship could not only be attributed to their higher psychiatric morbidity. In women, there was no such clear relationship.     

Sexual Orientation and Fluctuating Asymmetry in Men and Women

Previous research suggests that individuals’ sexual orientation may be affected by developmental instability (DI) induced by exposure to prenatal stresses. We tested this relationship using fluctuating asymmetry (FA), the small random deviations from symmetry that arise in otherwise bilaterally symmetrical traits as a consequence of developmental noise and developmental instability. Differences among individuals reflect variation in their exposure to and ability to accommodate for stresses experienced during development as well as to developmental noise that arises due to cellular stocasticity. FA measurements for 156 heterosexual and 132 homosexual men and women participants provided strong support for the developmental instability hypothesis: FA was significantly higher in both male and female homosexuals (men: four of seven bilateral traits and composite FA values (cFA); women: five of seven bilateral traits and composite FA values). Although finger-length ratios (FLRs), an indirect marker for prenatal hormones, were sex-atypical (e.g., feminized) for homosexual men, we failed to detect any relationship between FA levels and 2D:4D finger-length ratios (FLRs). Hence, although elevated levels of developmental stress appear to be linked to shifts in sexual orientation, the underlying mechanism does not seem to be connected to sex-atypical prenatal hormones. Additional analyses with sex atypical individuals are needed to confirm this.     

Sexual Partner Age Preferences of Homosexual and Heterosexual Men and Women

The sexual age preferences of 192 adults (equal groups of heterosexual men, heterosexual women, homosexual men, and homosexual women) were examined. Participants rated the sexual attractiveness of pictures of 15 male and 15 female faces arranged into five apparent average age categories ranging from 18 to 60 years. It was predicted that homosexual and heterosexual men would prefer younger partners of their preferred sex than would homosexual and heterosexual women and that age preference would not vary with participant age. Both predictions were supported, although homosexual women preferred older partners than expected. Results suggest that age and sex preferences develop independently.     

Handedness,sexual orientation,and gender-related personality traits in men and women

This study assessed large numbers of heterosexual and homosexual men and women on handedness and gender-related personality traits. Initial analyses employed a dichotomous measure of handedness (right-handed vs. non–right-handed). For men and women combined, homosexual participants had 50% greater odds of being non–right-handed than heterosexual participants, a statistically significant difference. Homosexual men had 82% greater odds of being non–right-handed than heterosexual men, a statistically significant difference, whereas homosexual women had 22% greater odds of being non–right-handed than heterosexual women, a nonsignificant difference. When participants were classified into five graduated categories of handedness, both men and women showed significant homosexual–heterosexual differences in handedness distributions. Within groups, handedness showed a number of weak but statistically significant associations with sex-typed occupational preferences, self-ascribed masculinity, and self-ascribed femininity, but not with instrumentality or expressiveness. Rates of non–right-handedness were virtually identical for heterosexual men and women, suggesting that sex differences in handedness may result from higher rates of homosexuality in men.     

The Effects of Sex,Sexual Orientation,and Digit Ratio (2D:4D) on Mental Rotation Performance

In spite of the reduced level of experimental control, this large scale study brought some clarity into the relation between mental rotation task (MRT) performance and a number of variables where contradictory associations had previously been reported in the literature. Clear sex differences in MRT were observed for a sample of 134,317 men and 120,783 women, with men outperforming women. There were also MRT differences as a function of sexual orientation: heterosexual men performed better than homosexual men and homosexual women performed better than heterosexual women. Although bisexual men performed better than homosexual men but less well than heterosexual men, no significant differences were observed between bisexual and homosexual women. MRT performance in both men and women peaked in the 20-30 year range, and declined significantly and markedly thereafter. Both men and women showed a significant negative correlation between left and right digit finger ratio and MRT scores, such that individuals with smaller digit ratios (relatively longer ring finger than index finger) performed better than individuals with larger digit ratios.     

Sex-Specificity in the Reward Value of Facial Attractiveness

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.     

Patterns of Sexual Arousal in Homosexual,Bisexual, and Heterosexual Men

The purpose of this study was to determine if self-identified bisexual, heterosexual, and homosexual men show differential genital and subjective arousal patterns to video presentations of bisexual, heterosexual, male homosexual, and lesbian sexual interactions. It was predicted that, relative to heterosexual and homosexual stimuli, bisexual men would show the highest levels of sexual arousal to bisexual erotic material, while this stimulus would induce relatively low levels of response in heterosexual and homosexual men. A sample of 59 men (19 homosexual, 13 bisexual, and 27 heterosexual) were presented with a series of 4-min sexual videos while their genital and subjective sexual responses were measured continuously. Bisexual men did not differ significantly in their responses to male homosexual stimuli (depicting men engaging in sex) from homosexual men, and they did not differ significantly in their responses to heterosexual (depicting two women, without same-sex contact, engaged in sex with a man) and lesbian (depicting women engaging in sex) stimuli from heterosexual men. However, bisexual men displayed significantly higher levels of both genital and subjective sexual arousal to a bisexual stimulus (depicting a man engaged in sex with both a man and a woman) than either homosexual or heterosexual men. The findings of this study indicate that bisexuality in men is associated with a unique and specific pattern of sexual arousal.     

Effects of Attractiveness and Status in Dating Desire in Homosexual and Heterosexual Men and Women

The present study examined partner preferences of homosexual and heterosexual men and woman, focusing on attractiveness and status. Homosexual (N = 591 men; M age = 28.87 years, SD = 10.21; N = 249 women; M age = 33.36 years, SD = 13.12) and heterosexual participants (N = 346 men; M age = 39.74 years, SD = 14.26; N = 400 women; M age = 35.93 years, SD = 13.72) rated the importance of attractiveness and social status of potential partners and then, in a vignette test, expressed their desire to date hypothetical potential partners based on photographs that varied in attractiveness and status-related profiles. With ratings, heterosexual men valued attractiveness the most, followed by homosexual men, heterosexual women, and homosexual women. Heterosexual women rated social status as most important. When status profiles were manipulated and accompanied with photographs of faces, the pattern of differences between homosexuals and heterosexuals supported the self-reported results. Overall, homosexual men and women have similar mate preferences to heterosexual men and women by showing more dating desire for attractive and high social status persons. Compared to attractiveness, status played a smaller role in dating desire.     

Older-sibling and younger-sibling sex ratios in Frisch and Hviid's (2006) national cohort study of two million Danes

Frisch and Hviid (2006) recently reported a study of variables that predicted heterosexual and homosexual marriage in a national cohort of Danish men and women. They found no evidence that older brothers increase the probability that a man will legally marry another man. They concluded that their data raise questions about the universality of the widely confirmed finding that older brothers increase the probability that a man will be sexually oriented towards other men (the fraternal birth order effect). In the present article, Frisch and Hviid's data were reanalyzed using one of the procedures that have been used in prior studies of fraternal birth order. The results showed that the sex ratio of older brothers to older sisters was significantly higher than the expected value of 106 in all four of their study groups (heterosexually married men, homosexually married men, heterosexually married women, and homosexually married women). In contrast, the sex ratio of younger brothers to younger sisters approximated 106 in all four groups. According to this analysis, the only group whose data resembled data from previous studies was the homosexually married males. The writer concluded that one cannot interpret findings about the correlates of heterosexual and homosexual marriage as if they were findings about the correlates of heterosexual and homosexual orientation, and that this is underscored by comparing the markedly different older-sibling sex ratios obtained from heterosexually married persons (in the Danish study) and those obtained from heterosexually oriented persons (in previous studies). It is unclear what implications, if any, Frisch and Hviid's findings have for the study of sexual orientation in general.     

Older-Sibling and Younger-Sibling Sex Ratios in Frisch and Hviid’s (2006) National Cohort Study of Two Million Danes

Frisch and Hviid (2006) recently reported a study of variables that predicted heterosexual and homosexual marriage in a national cohort of Danish men and women. They found no evidence that older brothers increase the probability that a man will legally marry another man. They concluded that their data raise questions about the universality of the widely confirmed finding that older brothers increase the probability that a man will be sexually oriented towards other men (the fraternal birth order effect). In the present article, Frisch and Hviid’s data were reanalyzed using one of the procedures that have been used in prior studies of fraternal birth order. The results showed that the sex ratio of older brothers to older sisters was significantly higher than the expected value of 106 in all four of their study groups (heterosexually married men, homosexually married men, heterosexually married women, and homosexually married women). In contrast, the sex ratio of younger brothers to younger sisters approximated 106 in all four groups. According to this analysis, the only group whose data resembled data from previous studies was the homosexually married males. The writer concluded that one cannot interpret findings about the correlates of heterosexual and homosexual marriage as if they were findings about the correlates of heterosexual and homosexual orientation, and that this is underscored by comparing the markedly different older-sibling sex ratios obtained from heterosexually married persons (in the Danish study) and those obtained from heterosexually oriented persons (in previous studies). It is unclear what implications, if any, Frisch and Hviid’s findings have for the study of sexual orientation in general.     

The Queen’s English: An Alternative,Biosocial Hypothesis for the Distinctive Features of “Gay Speech”

Popular stereotypes concerning the speech of homosexuals typically attribute speech patterns characteristic of the opposite-sex, i.e., broadly feminized speech in gay men and broadly masculinized speech in lesbian women. A small body of recent empirical research has begun to address the subject more systematically and to consider specific mechanistic hypotheses to account for the potentially distinctive features of homosexual speech. Results do not yet fully endorse the stereotypes but they do not entirely discount them either; nor do they cleanly favor any single mechanistic hypothesis. To contribute to this growing body of research, we report acoustic analyses of 2,875 vowel sounds from a balanced set of 125 speakers representing heterosexual and homosexual individuals of each sex from southern Alberta, Canada. Analyses focused on voice pitch and formant frequencies which together determine the principle perceptual features of vowels. There was no significant difference in mean voice pitch between heterosexual and homosexual men or between heterosexual and homosexual women, but there were significant differences in the formant frequencies of vowels produced by both homosexual groups compared to their heterosexual counterparts. Formant frequency differences were specific to only certain vowel sounds and some could be attributed to basic differences in body size between heterosexual and homosexual speakers. The remaining formant frequency differences were not obviously due to differences in vocal tract anatomy between heterosexual and homosexual speakers, nor did they reflect global feminization or masculinization of vowel production patterns in homosexual men and women, respectively. The vowel-specific differences observed could reflect social modeling processes in which only certain speech patterns of the opposite-sex, or of same-sex homosexuals, are selectively adopted. However, we introduce an alternative biosocial hypothesis, specifically that the distinctive, vowel-specific features of homosexual speakers relative to heterosexual speakers arise incidentally as a product of broader psychobehavioral differences between the two groups that are, in turn, continuous with and flow from the physiological processes that affect sexual orientation to begin with.