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Felesina T, Zietsch B. The Desirable Dad Hypothesis: Male Same-Sex Attraction as the Product of Selection for Paternal Care via Antagonistic Pleiotropy. ARCHIVES OF SEXUAL BEHAVIOR 2024; 53:1731-1745. [PMID: 38177607 DOI: 10.1007/s10508-023-02780-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 01/06/2024]
Abstract
Same-sex attraction, a heritable trait with a reproductive cost, lacks a comprehensive evolutionary explanation. Here we build on a hypothesis invoking antagonistic pleiotropy, which suggests that genes linked to male same-sex attraction remain in the gene pool because they have conferred some fitness advantage to heterosexual men possessing them. We posit the "desirable dad hypothesis," which proposes that alleles linked to male non-heterosexual orientations increase traits conducive to childcare; heterosexual men possessing same-sex attracted alleles are more desirable mating partners as a function of possessing superior paternal qualities. We conducted three studies to test predictions from this hypothesis. Results were consistent with all three predictions. Study 1 (N = 1632) showed that heterosexual men with same-sex attracted relatives were more feminine than men without, as indicated by self-report measures of femininity (η2 = .007), warmth (η2 = .002), and nurturance (η2 = .004 - .006). In Study 2 (N = 152), women rated feminine male profiles as more romantically appealing than masculine ones (d = 0.83)-but less so than profiles possessing a combination of feminine and masculine traits. In Study 3 (N = 153), women perceived feminine male profiles as depicting the best fathers and masculine profiles the worst (d = 1.56): consistent with the idea that femininity is attractive for childcare reasons. Together, these findings are consistent with the idea that sexual selection for male parental care may be involved in the evolution of male same-sex attraction.
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Affiliation(s)
- Thomas Felesina
- School of Psychology, The University of Queensland, Level 3, McElwain Building (24A), St Lucia, Brisbane, 4072, Australia.
| | - Brendan Zietsch
- School of Psychology, The University of Queensland, Brisbane, Australia
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VanderLaan DP, Skorska MN, Peragine DE, Coome LA. Carving the Biodevelopment of Same-Sex Sexual Orientation at Its Joints. ARCHIVES OF SEXUAL BEHAVIOR 2023; 52:2939-2962. [PMID: 35960401 DOI: 10.1007/s10508-022-02360-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/30/2022] [Accepted: 06/04/2022] [Indexed: 06/15/2023]
Abstract
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.
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Affiliation(s)
- Doug P VanderLaan
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada.
- Child and Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, Canada.
| | - Malvina N Skorska
- Child and Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Diana E Peragine
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
| | - Lindsay A Coome
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
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Tasos E. To What Extent are Prenatal Androgens Involved in the Development of Male Homosexuality in Humans? JOURNAL OF HOMOSEXUALITY 2022; 69:1928-1963. [PMID: 34080960 DOI: 10.1080/00918369.2021.1933792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
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.
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Affiliation(s)
- Emmanouil Tasos
- School of Clinical Medicine, University of Cambridge, Cambridge, UK
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Cui J, Pei M, Su Y. Gender-related friend preferences of youths with different sexual orientations: the effects of gender role and sexual attraction. PSYCHOLOGY & SEXUALITY 2022. [DOI: 10.1080/19419899.2020.1734066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Jingmeng Cui
- Beijing Key Laboratory of Behavior and Mental Health, School of Psychological and Cognitive Sciences, Peking University, Beijing, China
| | - Meng Pei
- Beijing Key Laboratory of Behavior and Mental Health, School of Psychological and Cognitive Sciences, Peking University, Beijing, China
| | - Yanjie Su
- Beijing Key Laboratory of Behavior and Mental Health, School of Psychological and Cognitive Sciences, Peking University, Beijing, China
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Skorska MN, Coome LA, Peragine DE, Aitken M, VanderLaan DP. An anthropometric study of sexual orientation and gender identity in Thailand. Sci Rep 2021; 11:18432. [PMID: 34531440 PMCID: PMC8445993 DOI: 10.1038/s41598-021-97845-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 08/31/2021] [Indexed: 11/23/2022] Open
Abstract
The biodevelopment of psychological sex differentiation is putatively reflected in several anthropometrics. We examined eight anthropometrics in 1404 Thai participants varying in sex, sexual orientation, and gender identity/expression: heterosexual men and women, gay men, lesbian women, bisexual women, sao praphet song (transgender birth-assigned males), toms (transgender birth-assigned females), and dees (birth-assigned females attracted to toms). Exploratory factor analyses indicated the biomarkers should be analyzed independently. Using regressions, in birth-assigned males, less male-typical second-to-fourth digit ratios in the left hand were associated with sexual orientation towards men regardless of gender identity/expression, whereas shorter height and long-bone growth in the arms and legs were more evident among sao praphet song-who are both sexually oriented towards men and markedly feminine. In birth-assigned females, there were no clear sexual orientation effects, but there were possible gender-related effects. Groups of individuals who tend to be more masculine (i.e., toms, lesbians) showed more male-typical patterns on weight and leg length than some groups of individuals who tend to be less masculine (i.e., heterosexual women, dees). Thus, it appears the various anthropometrics inform separate biodevelopmental processes that differentially relate to sexual orientation and gender identity/expression depending on the measure in question as well as birth-assigned sex.
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Affiliation(s)
- Malvina N Skorska
- Child & Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, M6J 1H4, Canada
| | - Lindsay A Coome
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada
| | - Diana E Peragine
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada
| | - Madison Aitken
- Department of Psychiatry, University of Toronto, Toronto, ON, M5T 1R8, Canada
| | - Doug P VanderLaan
- Child & Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, M6J 1H4, Canada.
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada.
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Xu Y, Norton S, Rahman Q. A longitudinal birth cohort study of early life conditions, psychosocial factors, and emerging adolescent sexual orientation. Dev Psychobiol 2019; 62:5-20. [DOI: 10.1002/dev.21894] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/15/2019] [Accepted: 06/22/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Yin Xu
- Department of Psychology, Institute of Psychiatry Psychology and Neuroscience King's College London London UK
| | - Sam Norton
- Department of Psychology, Institute of Psychiatry Psychology and Neuroscience King's College London London UK
| | - Qazi Rahman
- Department of Psychology, Institute of Psychiatry Psychology and Neuroscience King's College London London UK
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Swift-Gallant A. Individual differences in the biological basis of androphilia in mice and men. Horm Behav 2019; 111:23-30. [PMID: 30579744 DOI: 10.1016/j.yhbeh.2018.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/21/2018] [Accepted: 12/11/2018] [Indexed: 02/07/2023]
Abstract
For nearly 60 years since the seminal paper from W.C Young and colleagues (Phoenix et al., 1959), the principles of sexual differentiation of the brain and behavior have maintained that female-typical sexual behaviors (e.g., lordosis) and sexual preferences (e.g., attraction to males) are the result of low androgen levels during development, whereas higher androgen levels promote male-typical sexual behaviors (e.g., mounting and thrusting) and preferences (e.g., attraction to females). However, recent reports suggest that the relationship between androgens and male-typical behaviors is not always linear - when androgen signaling is increased in male rodents, via exogenous androgen exposure or androgen receptor overexpression, males continue to exhibit male-typical sexual behaviors, but their sexual preferences are altered such that their interest in same-sex partners is increased. Analogous to this rodent literature, recent findings indicate that high level androgen exposure may contribute to the sexual orientation of a subset of gay men who prefer insertive anal sex and report more male-typical gender traits, whereas gay men who prefer receptive anal sex, and who on average report more gender nonconformity, present with biomarkers suggestive of low androgen exposure. Together, the evidence indicates that for both mice and men there is an inverted-U curvilinear relationship between androgens and sexual preferences, such that low and high androgen exposure increases androphilic sexual attraction, whereas relative mid-range androgen exposure leads to gynephilic attraction. Future directions for studying how individual differences in biological development mediate sexual behavior and sexual preferences in both mice and humans are discussed.
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Affiliation(s)
- Ashlyn Swift-Gallant
- Neuroscience Program, Michigan State University, 293 Farm Lane, East Lansing, MI 48824, USA; Department of Psychology, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
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Skorska MN, Bogaert AF. Prenatal Androgens in Men's Sexual Orientation: Evidence for a More Nuanced Role? ARCHIVES OF SEXUAL BEHAVIOR 2017; 46:1621-1624. [PMID: 28534216 DOI: 10.1007/s10508-017-1000-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 05/06/2017] [Indexed: 06/07/2023]
Affiliation(s)
- Malvina N Skorska
- Department of Psychology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada.
| | - Anthony F Bogaert
- Department of Psychology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
- Department of Health Sciences, Brock University, St. Catharines, ON, Canada
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Skorska MN, Bogaert AF. Pubertal Stress and Nutrition and their Association with Sexual Orientation and Height in the Add Health Data. ARCHIVES OF SEXUAL BEHAVIOR 2017; 46:217-236. [PMID: 27511207 PMCID: PMC5925759 DOI: 10.1007/s10508-016-0800-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 06/03/2016] [Accepted: 06/22/2016] [Indexed: 05/29/2023]
Abstract
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.
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Affiliation(s)
- Malvina N Skorska
- Department of Psychology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada.
| | - Anthony F Bogaert
- Department of Psychology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
- Department of Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
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