Sex Differences in the Flexibility of Sexual Orientation: A Multidimensional Retrospective Assessment

The flexibility of sexual orientation in men and women was examined by assessing self-reported change over time for three dimensions of sexual orientation (sexual fantasy, romantic attraction, and sexual behavior) across three categorical classifications of current sexual orientation (heterosexual, bisexual, and gay). The primary purpose of the study was to determine if there were sex differences in the flexibility (i.e., change over time) of sexual orientation and how such differences were manifested across different dimensions of orientation over the lifespan. Retrospective, life-long ratings of sexual orientation were made by 762 currently self-identified heterosexual, bisexual, and gay men and women, aged 36 to 60, via a self-report questionnaire. Cumulative change scores were derived for each of the three dimensions (fantasy, romantic attraction, and sexual behavior) of orientation by summing the differences between ratings over consecutive 5-year historical time periods (from age 16 to the present). Sex differences were observed for most, but not all, classification groups. There were significant sex differences in reported change in orientation over time for gays and heterosexuals, with women reporting greater change in orientation over time than did men. Bisexual men and women did not differ with respect to self-reported change in orientation.     

Sexual orientation after prenatal exposure to exogenous estrogen

Thirty women aged 17 to 30 years with documented prenatal exposure to the nonsteroidal synthetic estrogen diethylstilbestrol (DES) were compared to thirty women of similar demographic characteristics from the same medical clinic who had a history of abnormal Pap smear findings. A subsample of the DES women were also compared to their DES-unexposed sisters. Sexual orientation in its multiple components was assessed by systematic semistructured interviews. In comparison to both control groups, the DES women showed increased bisexuality and homosexuality. However, about 75% of the DES women were exclusively or nearly exclusively heterosexual. Nonhormonal and hormonal interpretations of these findings are discussed.This research was supported in part by U.S.P.H.S. research grants MH-34635 (NIMH), Y01-CN-00711 (NCI), and MH-30906 (NIMH).     

Sexual orientation and cognitive abilities

We asked whether homosexual and heterosexual men and women differ on standard measures of cognitive ability. Subjects were adults recruited for a family study of sexual orientation. They completed the Fy Scale of the California Psychological Inventory, a self-administered measure of psychological femininity, and were given subtests of the Wechsler Adult Intelligence Scale and the Primary Mental Abilities test which had been previously shown to discriminate between the sexes. We predicted that homosexual subjects would score significantly in the gender-atypical direction on the Fy scale. We also predicted that they would achieve scores on the tests of cognitive abilities significantly in the direction of the other gender. Comparisons were made between homosexual and heterosexual individuals within gender. Also, comparisons were made between heterosexual men and women to see if our results replicate differences typically found between the genders. As predicted, both homosexual men and women were strongly gender-atypical on the Fy scale relative to their heterosexual counterparts. However, neither differed from heterosexuals on any of the measures of cognitive abilities. Heterosexual men did better than women on the Primary Mental Abilities spatial relations test. We conclude that sexual orientation is not related to specific cognitive abilities.Supported in part by NIMH grant 32,170 to Dr. Pillard.     

Sexual orientation and performance on sexually dimorphic motor tasks

Performance of homosexual and heterosexual men and women on two motor tasks which reliably demonstrate sex differences in opposite directions was examined. A Throw-to-Target Task and the Purdue Pegboard were administered to undergraduate students matched for age and program of study. A two-way ANOVA (Sex × Sexual Orientation) of the Throw data showed a significant interaction,F(1, 90) = 16.22,p 0.001, and a trend for an effect of sex,F(1, 90) = 3.72,p < 0.06. Heterosexual men outperformed heterosexual women, whereas gay men threw less accurately and lesbians tended to throw more accurately than their heterosexual counterparts. Differences in sports history or hand strength did not account for these effects. Analysis of the Pegboard scores found no interaction or main effect of sexual orientation, but the effect of sex was significant,F(1,63) = 7.01,p 0.02. Regardless of sexual orientation, women outperformed men and this difference remained significant even when a measure of finger size was partialed out. This study provides new evidence suggesting an association between sexual orientation and motor-performance profiles. As with cognitive tasks, the motor-performance profiles of homosexuals are composites of some male-typical and some female-typical abilities. To the extent that sociological factors have been controlled, the study suggests that both sexual orientation and motor/cognitive predispositions may have early biological contributions.This research was supported by a grant from the Medical Research Council, Ottawa, to D. Kimura.     

Sexual orientation and boyhood gender conformity: Development of the Boyhood Gender Conformity Scale (BGCS)

Two hundred twenty-eight respondents (110 heterosexuals and 118 homosexuals) completed a survey containing a 20-item Boyhood Gender Conformity Scale (BGCS). This scale was largely composed of edited and abridged gender items from Part A of Freund et al.'s Feminine Gender Identity Scale (FGISA) and Whitam's childhood indicators. The combined scale was developed in an attempt to obtain a reliable, valid, and potent discriminating instrument for accurately classifying adult male respondents for sexual orientation on the basis of their reported boyhood gender conformity or nonconforming behavior and identity. In addition, 33% of these respondents were administered the original FGIS-A and Whitam inventory during a 2-week test-retest analysis conducted to determine the validity and reliability of the new instrument. All the original items significantly discriminated between heterosexual and homosexual respondents. From these a 13-item function and a 5-item function proved to be the most powerful discriminators between the two groups. Significant correlations between each of the three scales and a very high test-retest correlation coefficient supported the reliability and validity assumption for the BGCS. The conclusion was made that the five-item function (playing with boys, prefering boys' games, imagining self as sports figure, reading adventure and sports stories, considered a sissy) was the most potent and parsimonious discriminator among adult males for sexual orientation. It was similarly noted that the absence of masculine behaviors and traits appeared to be a more powerful predictor of later homosexual orientation than the traditionally feminine or cross-sexed traits and behaviors.     

Defining and Measuring Sexual Orientation: A Review

How to define and identify sexual orientations for the purpose of constructing representative samples of homosexuals, bisexuals, and heterosexuals is unclear and confusing to researchers. Different definitions and measures have been proposed and used to develop samples since the 1860s when sexual orientations first gained widespread research interest. Unfortunately, the definitions and measurement tools used since men result in the selection of divergent and incomparable samples. If advances in the understanding of sexual orientations are to be made, it is critical that definitions and measures of sexual orientation be standardized. This paper reviews and critiques definitions and measures of sexual orientation mat have been proposed and used by researchers over the past century. This review is intended to further our understanding of this subject and to encourage researchers to be critical of how they classify subjects based upon sexual orientation.     

Cultural Universals and Differences in Male Homosexuality: The Case of a Brazilian Fishing Village

This study investigated whether homosexually identified males in a small Brazilian fishing community are similar to homosexually identified males described in the international literature. In addition, it attempted to distinguish heterosexuals who have sex with homosexuals from other heterosexuals. A total of 41 men were classified into three sexual categories: paneleiros (“pan cabinets”), who have sex only with men, and invariably so in a bottom position; persistent heterosexuals, who have sex only with women; and paneleiro lovers, who have sex with women and with paneleiros, but invariably in a top position. There were significant differences in childhood play activities, sexual inclinations, and sports preferences between paneleiros and non-paneleiros; however, paneleiro lovers and persistent heterosexuals were not significantly different with regard to these variables or with regard to access to women. These findings add to the cross-cultural literature on childhood cross-gender behavior and homoerotic activities among non-homosexually identified males.     

The prevalence of homosexual behavior and attraction in the United States,the United Kingdom and France: Results of national population-based samples

Researchers determining the prevalence of homosexuality in nationally representative samples have focused upon determining the prevalence of homosexual behavior, ignoring those individuals whose sexual attraction to the same sex had not resulted in sexual behavior. We examine the use of sexual attraction as well as sexual behavior to estimate the prevalence of homosexuality in the United States, the United Kingdom, and France using the Project HOPE International Survey of AIDS-Risk Behaviors. We find that 8.7, 7.9, and 8.5% of males and 11.1, 8.6, and 11.7% of females in the United States, the United Kingdom, and France, respectively, report some homosexual attraction but no homosexual behavior since age 15. Further, considering homosexual behavior and homosexual attraction as different but overlapping dimensions of homosexuality, we find 20.8, 16.3, and 18.5% of males, and 17.8, 18.6, and 18.5% of females in the United States, the United Kingdom, and France report either homosexual behavior or homosexual attraction since age 15. Examination of homosexual behavior separately finds that 6.2, 4.5, and 10.7% of males and 3.6, 2.1, and 3.3% of females in the United States, the United Kingdom, and France, respectively, report having had sexual contact with someone of the same sex in the previous 5 years. Our findings highlight the importance of using more than just homosexual behavior to examine the prevalence of homosexuality.     

Sexual orientation as a risk factor for bulimic symptoms

OBJECTIVE: This study was carried out to examine whether sexual orientation predicts future bulimic symptoms and whether alleged risk factors associated with non-heterosexual sexual orientation explain the increased risk. METHOD: A nationally representative sample of Norwegian high school students (age 14-19; N=2,924) completed self-reports about bulimic symptoms by means of the Bulimic Investigatory Test-Edinborough (BITE), same-sex sexual experience, degree of sexual attraction to the same sex, and alleged risk factors. They were reexamined 5 years later (T2). RESULTS: Same-sex sexual experience before T1 increased the prevalence of bulimic symptoms at T2. Males who were attracted to the same sex at T1 had higher odds for bulimic symptoms compared with heterosexual males. These associations were still significant after controlling for initial bulimic symptoms and alleged risk factors. CONCLUSION: Same-sex sexual experience in both genders and non-heterosexual sexual attraction among males predict future bulimic symptoms. Commonly advocated explanations for this elevated risk were not supported.     

True Nature: A Theory of Human Sexual Evolution. Part 1

There exists an unfounded and unproven common sense belief that human beings possess the innate mechanistic urge to reproduce clearly evident in the behavior of all other sexually reproducing animals. As such, the heterosexual component of human behavior is by and large viewed as being genetic, whereas it is homosexuality that is primarily the focus of scientific investigations into human sexual orientation. A historical review of homosexuality in diverse cultures reveals that significantly many cultures have existed where (male) bisexuality has been rather universal and that all cultures have condemned exclusive homosexuality, either legally or with the threat of social rejection. Neither of these facts can be rationalized using the ballpark 10% statistic for homosexuality believed to be representative of human beings. This paper will attempt to provide a general underlying explanation for human sexuality as a whole. It will be argued that the varied forms of human sexual expression may be explained to some extent with the view that by virtue of their supreme intelligence, human beings do not possess an instinct to engage in heterosexual intercourse, human sexual orientation is fully determined by environment alone, and that due to rather universal childhood behavioral tendencies, human beings have a bias for acquiring a homosexual orientation over a heterosexual one or a bisexual one. Controlling this dominant homosexual tendency has always been a basic requirement for the propagation of societies.     

A family study of sexual orientation

Unmarried men aged 25–35 were recruited through newspaper and radio advertisements for a family studyof sexual orientation.Fifty predominantly homosexual and 50 predominantly heterosexual men comprised the index subjects. The test, questionnaire, and interview battery is described. Subjects were asked about the sexual orientations of their relatives. The homosexual index men report a significant excess of homosexual brothers and more distant male relatives but not of homosexual sisters or female relatives. Moreover, the percentage of homosexual brothers increases with the Kinsey rating of the index subjects. Overall, about 25% of brothers of homosexual men are reported also to be homosexual. Supported by NIMH Grant MH 32170.     

Homosexual orientation in twins: A report on 61 pairs and three triplet sets

Twin pairs in which at least one twin is homosexual were solicited through announcements in the gay press and personal referrals from 1980 to the present. An 18-page questionnaire on the sexuality of twins was filled out by one or both twins. Thirty-eight pairs of monozygotic twins (34 male pairs and 4 female pairs) were found to have a concordance rate of 65.8% for homosexual orientation. Twenty-three pairs of dizygotic twins were found to have a concordance rate of 30.4% for homosexual orientation. In addition, three sets of triplets were obtained. Two sets contained a pair of monozygotic twins concordant for sexual orientation with the third triplet dizygotic and discordant for homosexual orientation. A third triplet set was monozygotic with all three concordant for homosexual orientation. These findings are interpreted as supporting the argument for a biological basis in sexual orientation.     

The Prevalence of Bisexual and Homosexual Orientation and Related Health Risks Among Adolescents in Northern Thailand

Homo- or bisexual (HB) adolescents may have greater and different health risks than the population of heterosexual adolescents. We assessed sexual orientation and health risk behaviors in 1,725 consenting 15- to 21-year-old vocational school students in northern Thailand. Data were collected using audio-computer-assisted self-interviewing. Nine percent of males and 11.2% of females identified themselves as homo- or bisexual. HB males had an earlier mean age at sexual debut (14.7 years) and a higher mean number of lifetime sexual partners (7.9) than did heterosexual males (16.8 years and 5.8 partners, respectively). HB males (25.9%) and females (32.2%) were sexually coerced more often than were heterosexual males (4.6%) and females (19.6%). Drug use was reported significantly more frequently by HB females and significantly less frequently by HB males than by their heterosexual counterparts. HB males showed more signs of social isolation and depression than did heterosexual males. We conclude that HB adolescents in northern Thailand are at greater and different health risks than are their heterosexual counterparts. Differential health education messages for HB and heterosexual youth are warranted.     

Exotic Becomes Erotic: Interpreting the Biological Correlates of Sexual Orientation

Although biological findings currently dominate the research literature on the determinants of sexual orientation, biological theorizing has not yet spelled out a developmental path by which any of the various biological correlates so far identified might lead to a particular sexual orientation. The Exotic-Becomes-Erotic (EBE) theory of sexual orientation (Bem, 1996) attempts to do just that, by suggesting how biological variables might interact with experiential and sociocultural factors to influence an individual's sexual orientation. Evidence for the theory is reviewed, and a path analysis of data from a large sample of twins is presented which yields preliminary support for the theory's claim that correlations between genetic variables and sexual orientation are mediated by childhood gender non-conformity.     

Interaction of older brothers and sex-typing in the prediction of sexual orientation in men

Numerous studies indicate that homosexual men have, on average, more older brothers than do heterosexual men. One explanation of the older brother effect comes from D. J. Bem (1996), who argued that an increased number of older brothers in homosexual men can result if older brothers enhance a feminine boy's sense of being different from (and hence his attraction to) other males. Thus, he argued that an interaction between older brothers and sex-typing will occur, such that when a boy is high in femininity, number of older brothers may strongly predict a homosexual orientation; and when a boy is low in femininity, number of older brothers may not or may only weakly predict a homosexual orientation. In this study, the relations among sibling characteristics (e.g., older brothers), childhood sex-typing, and sexual orientation were examined using a database of a large sample of homosexual and heterosexual men (N > 1,000) archived at the Kinsey Institute (A. P. Bell, M. S. Weinberg, & S. K. Hammersmith, 1981a). No significant Older Brother × Sex-Typing interaction effect was observed. These results join other recent evidence that postnatal (e.g., learning/environmental) mechanisms probably do not underlie the older brother effect in men.     

Sexual orientation and eating psychopathology: the role of masculinity and femininity

OBJECTIVE: Previous research suggests that eating disorders are related to homosexuality in men, although links with female sexual orientation are less clear. Appearance factors have generally been implicated in this relationship. However, previous studies have failed to consider the role of femininity, even though evidence suggests that this is a more critical factor than sexual preference. The aim of this study was to consider the relationship between gender-role orientation and eating psychopathology in nonclinical men and women of different sexual orientations. METHOD: One hundred university students (40 homosexual; 60 heterosexual) completed the Bem Sex Role Inventory and the Eating Attitudes Test. RESULTS: For the group as a whole, there were links between femininity and high levels of eating psychopathology, whereas masculinity was associated with relatively healthy eating-related attitudes and behaviors. When considering the role of sexual orientation, these links were specific to homosexual men and women. CONCLUSIONS: In relation to homosexual men and women, the results support a model where femininity might be seen as a specific risk factor for eating disorders, whereas masculinity is likely to be a protective factor. Methodological and conceptual implications are discussed.     

Sexual language usage in different interpersonal contexts: A comparison of gender and sexual orientation

Previous investigators have demonstrated that gender differences exist in the use of sexual language in various interpersonal contexts. However, sexual orientation has not been addressed in any study regarding sexual language usage. This investigation examined the use of sexual language for female and male in different interpersonal contexts based upon sexual orientation. Respondents were 440 university students: 202 heterosexual female, 30 lesbian, 173 heterosexual male, and 35 gay male. Findings indicate that differences in sexual language usage in interpersonal contexts is significant for gender as well as for sexual orientation. Conjecture is made for the implications this may have on intimate relationships.     

Dermatoglyphics, Handedness, Sex, and Sexual Orientation

Both handedness and dermatoglyphic asymmetry reflect early, prenatal influences and both have been reported to be associated with male sexual orientation; handedness has been related to female sexual orientation as well. Neurohormonal and developmental perturbation are two competing hypothesis that attempt to explain these connections. We attempted to replicate these associations and to extend dermatoglyphic asymmetry findings to women. Dermatoglyphic directional asymmetry and fluctuating asymmetry were unrelated to sexual orientation. Homosexual women, but not homosexual men, had highly significant increases in non–right-handedness compared with same-sex heterosexual controls. Although this pattern of results does not allow resolution of the two competing models, it does lend additional support to a biological basis of sexual orientation.     

Bed Death and Other Lesbian Sexual Problems Unraveled: A Qualitative Study of the Sexual Health of Lesbian Women Involved in a Relationship

ABSTRACT

Objectives: To shed light on lesbian “bed death” among lesbian women. To explore the wishes and expectations of lesbian women with respect to healthcare professionals.

Methods: Semi-structured interviews with 30 self-identified lesbian women. The interviews were audio recorded. Three researchers classified and analyzed the most important themes.

Results: The women indicated few sexual problems except for “bed death,” a quasi-complete cessation of sexual activity. Twenty-three women experienced “bed death” during the current relationship or a previous one. The factors felt by the women to contribute to “bed death” were environmental influences, the existence of a symbiotic relationship, hormonal factors, and reduced sexual initiative. The women indicated that they would like family doctors to adopt a neutral attitude, be knowledgeable about homosexuality, and be able to recognize homosexuality in their patients.

Discussion: A careful examination of the potential causes of “bed death” suggests that the phenomenon is more closely linked to a patient's gender than to her sexual orientation. Lesbian women would also like general practitioners to possess at least some basic knowledge about homosexuality.