Skip to main content

Testing the Affiliation Hypothesis of Homoerotic Motivation in Humans: The Effects of Progesterone and Priming

Abstract

The frequency of homoerotic behavior among individuals who do not identify as having an exclusively homosexual sexual orientation suggests that such behavior potentially has adaptive value. Here, we define homoerotic behavior as intimate erotic contact between members of the same sex and affiliation as the motivation to make and maintain social bonds. Among both male and female nonhuman primates, affiliation is one of the main drivers of homoerotic behavior. Correspondingly, in humans, both across cultures and across historical periods, homoerotic behavior appears to play a role in promoting social bonds. However, to date, the affiliation explanation of human homoerotic behavior has not been adequately tested experimentally. We developed a measure of homoerotic motivation with a sample of 244 men and women. Next, we found that, in women (n = 92), homoerotic motivation was positively associated with progesterone, a hormone that has been shown to promote affiliative bonding. Lastly, we explored the effects of affiliative contexts on homoerotic motivation in men (n = 59), finding that men in an affiliative priming condition were more likely to endorse engaging in homoerotic behavior compared to those primed with neutral or sexual concepts, and this effect was more pronounced in men with high progesterone. These findings constitute the first experimental support for the affiliation account of the evolution of homoerotic motivation in humans.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3

References

  1. Adams, D. B., Gold, A. R., & Burt, A. D. (1978). Rise in female-initiated sexual activity at ovulation and its suppression by oral contraceptives. New England Journal of Medicine, 299, 1145–1150.

    PubMed  Article  Google Scholar 

  2. Adams, H. E., Wright, L. W., & Lohr, B. A. (1996). Is homophobia associated with homosexual arousal? Journal of Abnormal Psychology, 105, 440–445.

    PubMed  Article  Google Scholar 

  3. Alexander, G. M., Sherwin, B. B., Bancroft, J., & Davidson, D. W. (1990). Testosterone and sexual behavior in oral contraceptive users and nonusers: A prospective study. Hormones and Behavior, 24, 388–402.

    PubMed  Article  Google Scholar 

  4. Andersen, M. L., & Tufik, S. (2006). Does male sexual behavior require progesterone? Brain Research Reviews, 51, 136–143.

    PubMed  Article  Google Scholar 

  5. Bartz, J. A., Zaki, J., Bolger, N., & Ochsner, K. N. (2011). Social effects of oxytocin in humans: Context and person matter. Trends in Cognitive Sciences, 15, 301–309.

    PubMed  Google Scholar 

  6. Bora, E., Yucel, M., & Allen, N. B. (2009). Neurobiology of human affiliative behaviour: Implications for psychiatric disorders. Current Opinion in Psychiatry, 22, 320–325.

    PubMed  Article  Google Scholar 

  7. Bowles, S. (2009). Did warfare among ancestral hunter-gatherers affect the evolution of human social behaviors? Science, 324, 1293–1298.

    PubMed  Article  Google Scholar 

  8. Brown, S. L., Fredrickson, B. L., Wirth, M. M., Poulin, M. J., Meier, E. A., Heaphy, E. D., … Schutheiss, O. C. (2009). Social closeness increases salivary progesterone in humans. Hormones and Behavior, 56, 108–111.

    PubMed Central  PubMed  Article  Google Scholar 

  9. Campbell, A. (2008). Attachment, aggression and affiliation: The role of oxytocin in female social behavior. Biological Psychology, 77, 1–10.

    PubMed  Article  Google Scholar 

  10. Chivers, M. L., Rieger, G., Latty, E., & Bailey, J. M. (2004). A sex difference in the specificity of sexual arousal. Psychological Science, 15, 736–744.

    PubMed  Article  Google Scholar 

  11. Chivers, M. L., Seto, M. C., Lalumiere, M. L., Laan, E., & Grimbos, T. (2010). Agreement of self-reported and genital measures of sexual arousal in men and women: A meta-analysis. Archives of Sexual Behavior, 39, 5–56.

    PubMed Central  PubMed  Article  Google Scholar 

  12. Ciani, A. C., Cermelli, P., & Zanzotto, G. (2008). Sexually antagonistic selection in human male homosexuality. PLoS One, 3, e2282.

    Article  Google Scholar 

  13. DeWall, C. N., MacDonald, G., Webster, G. D., Masten, C. L., Baumeister, R. F., Powell, C., … Eisenberger, N. I. (2010). Acetaminophen reduces social pain. Psychological Science, 21, 931.

    PubMed  Article  Google Scholar 

  14. Diamond, M. (1993). Homosexuality and bisexuality in different populations. Archives of Sexual Behavior, 22, 291–310.

    PubMed  Article  Google Scholar 

  15. Diamond, L. M. (2012). The desire disorder in research on sexual orientation in women: Contributions of dynamical systems theory. Archives of Sexual Behavior, 41, 73–83.

    PubMed  Article  Google Scholar 

  16. Diamond, L. M., & Wallen, K. (2011). Sexual minority women’s sexual motivation around the time of ovulation. Archives of Sexual Behavior, 40, 237–246.

    PubMed  Article  Google Scholar 

  17. Eisenberger, N. I., Jarcho, J. M., Lieberman, M. D., & Naliboff, B. D. (2006). An experimental study of shared sensitivity to physical pain and social rejection. Pain, 126, 132–138.

    PubMed  Article  Google Scholar 

  18. Eisenberger, N. I., & Lieberman, M. D. (2004). Why rejection hurts: A common neural alarm system for physical and social pain. Trends in Cognitive Sciences, 8, 294–300.

    PubMed  Article  Google Scholar 

  19. Fessler, D. M. T. (2003). No time to eat: An adaptationist account of periovulatory behavioral changes. Quarterly Review of Biology, 78, 3–21.

    PubMed  Article  Google Scholar 

  20. Fleischman, D. S., Navarrete, C. D., & Fessler, D. M. T. (2010). Oral contraceptives suppress ovarian hormone production. Psychological Science, 21, 750–752.

    PubMed  Article  Google Scholar 

  21. Frye, C. A. (2006). An overview of oral contraceptives: mechanism of action and clinical use. Neurology, 66, S29–S36.

    PubMed  Article  Google Scholar 

  22. Gangestad, S. W., & Thornhill, R. (1998). Menstrual cycle variation in women’s preferences for the scent of symmetrical men. Proceedings of the Royal Society B, 265, 927–933.

    PubMed Central  PubMed  Article  Google Scholar 

  23. Gavrilets, S., & Rice, W. R. (2006). Genetic models of homosexuality: generating testable predictions. Proceedings of the Royal Society B, 273, 3031–3038.

    PubMed Central  PubMed  Article  Google Scholar 

  24. Guida, M., Di Spiezio, S. A., Bramante, S., Sparice, S., Acunzo, G., Tomaselli, G. A., … Nappi, C. (2005). Effects of two types of hormonal contraception–oral versus intravaginal—on the sexual life of women and their partners. Human Reproduction, 20, 1100–1106.

    PubMed  Article  Google Scholar 

  25. Haselton, M. G., & Gangestad, S. W. (2006). Conditional expression of women’s desires and men’s mate guarding across the ovulatory cycle. Hormones and Behavior, 49, 509–518.

    PubMed  Article  Google Scholar 

  26. Hatcher, R. A., & Namnoum, A. B. (2004). The menstrual cycle. Contraceptive Technology, 18, 63–72.

  27. Hill, K., & Hurtado, A. M. (2009). Cooperative breeding in South American hunter-gatherers. Proceedings of the Royal Society B, 276, 3863.

    PubMed Central  PubMed  Article  Google Scholar 

  28. Hrdy, S. (2009). Meet the alloparents: Shared child care may be the secret of human evolutionary success. Natural History, 118, 24–29.

    Google Scholar 

  29. Iemmola, F., & Camperio, A. C. (2009). New evidence of genetic factors influencing sexual orientation in men: Female fecundity increase in the maternal line. Archives of Sexual Behavior, 38, 393–399.

    PubMed  Article  Google Scholar 

  30. Jasienska, G., & Jasienski, M. (2008). Interpopulation, interindividual, intercycle, and intracycle natural variation in progesterone levels: A quantitative assessment and implications for population studies. American Journal of Human Biology, 20, 35–42.

    PubMed  Article  Google Scholar 

  31. Kinsey, A. C., Pomeroy, W. B., & Martin, C. E. (1948). Sexual behavior in the human male. Philadelphia: W. B. Saunders.

    Google Scholar 

  32. Kirkpatrick, R. C. (2000). The evolution of human homosexual behavior. Current Anthropology, 41, 385–413.

    PubMed  Article  Google Scholar 

  33. Kuhle, B., & Radtke, S. (2013). Born both ways: The alloparenting hypothesis for sexual fluidity in women. Evolutionary Psychology, 11, 304–323.

    PubMed  Google Scholar 

  34. MacDonald, G., & Leary, M. R. (2005). Why does social exclusion hurt? The relationship between social and physical pain. Psychological Bulletin, 131, 202–223.

    PubMed  Article  Google Scholar 

  35. Maner, J. K., Miller, S. L., Schmidt, N. B., & Eckel, L. A. (2010). The endocrinology of exclusion. Psychological Science, 21, 581–588.

    PubMed  Article  Google Scholar 

  36. McCullough, M. E., Churchland, P. S., & Mendez, A. J. (2013). Problems with measuring peripheral oxytocin: Can the data on oxytocin and human behavior be trusted? Neuroscience and Biobehavioral Reviews, 37, 1485–1492.

    PubMed  Article  Google Scholar 

  37. Mehta, P. H., & Josephs, R. A. (2010). Social endocrinology hormones and social motivation. In D. Dunning (Ed.), Social motivation (pp. 171–189). New York: Psychology Press.

    Google Scholar 

  38. Miller, S. L. (2011). Hormones and social affiliation: Menstrual cycle shifts in progesterone underlie women’s attention to signs of social support. Unpublished doctoral dissertation, Florida State University, Tallahassee.

  39. Muscarella, F. (1999). The homoerotic behavior that never evolved. Journal of Homosexuality, 37, 1–18.

    PubMed  Article  Google Scholar 

  40. Muscarella, F. (2000). The evolution of homoerotic behavior in humans. Journal of Homosexuality, 40, 51–77.

    PubMed  Article  Google Scholar 

  41. Muscarella, F. (2006). The evolution of male-male sexual behavior in humans: The alliance theory. Journal of Psychology & Human Sexuality, 18, 275–311.

    Article  Google Scholar 

  42. Muscarella, F., Cevallos, A. M., Siler-Knogl, A., & Peterson, L. M. (2005). The alliance theory of homosexual behavior and the perception of social status and reproductive opportunities. Neuroendocrinology Letters, 26, 771–774.

    PubMed  Google Scholar 

  43. Navarrete, C. D., Fessler, D. M. T., Fleischman, D. S., & Geyer, J. (2009). Race bias tracks conception risk across the menstrual cycle. Psychological Science, 20, 661–665.

    PubMed  Article  Google Scholar 

  44. Poiani, A., & Dixson, A. F. (2010). Animal homosexuality: A biosocial perspective. Cambridge: Cambridge University Press.

    Book  Google Scholar 

  45. Rahman, Q., & Wilson, G. D. (2003). Born gay? The psychobiology of human sexual orientation. Personality and Individual Differences, 34, 1337–1382.

    Article  Google Scholar 

  46. Reblin, M., & Uchino, B. N. (2008). Social and emotional support and its implication for health. Current Opinion in Psychiatry, 21, 201–205.

    PubMed Central  PubMed  Article  Google Scholar 

  47. Rieger, G., Chivers, M. L., & Bailey, J. M. (2005). Sexual arousal patterns of bisexual men. Psychological Science, 16, 579–584.

    PubMed  Article  Google Scholar 

  48. Rind, B., & Yuill, R. (2012). Hebephilia as mental disorder? A historical, cross-cultural, sociological, cross-species, non-clinical empirical, and evolutionary review. Archives of Sexual Behavior, 41, 797–829.

    PubMed  Article  Google Scholar 

  49. Ross, M. W., & Wells, A. L. (2000). The modernist fallacy in homosexual selection theories: Homosexual and homosocial exaptation in South Asian society. Psychology, Evolution & Gender, 2, 253–262.

    Article  Google Scholar 

  50. Savin-Williams, R. C., & Vrangalova, Z. (2013). Mostly heterosexual as a distinct sexual orientation group: A systematic review of the empirical evidence. Developmental Review, 33, 58–88.

    Article  Google Scholar 

  51. Schultheiss, O. C., Dargel, A., & Rohde, W. (2003). Implicit motives and gonadal steroid hormones: Effects of menstrual cycle phase, oral contraceptive use, and relationship status. Hormones and Behavior, 43, 293–301.

    PubMed  Article  Google Scholar 

  52. Schultheiss, O. C., Wirth, M. M., & Stanton, S. J. (2004). Effects of affiliation and power motivation arousal on salivary progesterone and testosterone. Hormones and Behavior, 46, 592–599.

    PubMed  Article  Google Scholar 

  53. Seeman, T. E. (1996). Social ties and health: The benefits of social integration. Annals of Epidemiology, 6, 442–451.

    PubMed  Article  Google Scholar 

  54. Silk, J. B., Alberts, S. C., & Altmann, J. (2003). Social bonds of female baboons enhance infant survival. Science, 302, 1231–1234.

    PubMed  Article  Google Scholar 

  55. Silk, J. B., Beehner, J. C., Bergman, T. J., Crockford, C., Engh, A. L., Moscovice, L. R., … Wittig, R. M. (2010). Strong and consistent social bonds enhance the longevity of female baboons. Current Biology, 20, 1359–1361.

    PubMed  Article  Google Scholar 

  56. Spector, I. P., Carey, M. P., & Steinberg, L. (1996). The Sexual Desire Inventory: Development, factor structure, and evidence of reliability. Journal of Sex and Marital Therapy, 22, 175–190.

    PubMed  Article  Google Scholar 

  57. Sugiyama, L. S. (2004). Illness, injury, and disability among Shiwiar forager-horticulturalists: Implications of health-risk buffering for the evolution of human life history. American Journal of Physical Anthropology, 123, 371–389.

    PubMed  Article  Google Scholar 

  58. Symons, D. (1979). The evolution of human sexuality. New York: Oxford University Press.

    Google Scholar 

  59. Van Honk, J., Montoya, E. R., Bos, P. A., van Vugt, M., & Terburg, D. (2012). New evidence on testosterone and cooperation. Nature, 485, E4–E5.

    PubMed  Article  Google Scholar 

  60. Van Vugt, M. (2009). Despotism, democracy, and the evolutionary dynamics of leadership and followership. American Psychologist, 64, 54–56.

    Article  Google Scholar 

  61. Van Vugt, M., & Park, J. H. (2010). The tribal instinct hypothesis: Evolution and the social psychology of intergroup relations. Visions in Conflict, 1, 20.

    Google Scholar 

  62. VanderLaan, D. P., Forrester, D. L., Petterson, L. J., & Vasey, P. L. (2012). Offspring production among the extended relatives of Samoan men and fa’afafine. PLoS One, 7, e36088.

    PubMed Central  PubMed  Article  Google Scholar 

  63. Vasey, P. L. (1995). Homosexual behavior in primates: A review of evidence and theory. International Journal of Primatology, 16, 173–204.

    Article  Google Scholar 

  64. Wallen, K., & Parsons, W. A. (1997). Sexual behavior in same-sexed nonhuman primates: Is it relevant to understanding human homosexuality? Annual Review of Sex Research, 8, 195–223.

    PubMed  Google Scholar 

  65. Wallwiener, M., Wallwiener, L. M., Seeger, H., Mueck, A. O., Zipfel, S., Bitzer, J., & Wallwiener, C. W. (2010). Effects of sex hormones in oral contraceptives on the female sexual function score: A study in German female medical students. Contraception, 82, 155–159.

    PubMed  Article  Google Scholar 

  66. Wilcox, A. J., Dunson, D. B., Weinberg, C. R., Trussell, J., & Baird, D. D. (2001). Likelihood of conception with a single act of intercourse: Providing benchmark rates for assessment of post-coital contraceptives. Contraception, 63, 211–215.

    PubMed  Article  Google Scholar 

  67. Wirth, M. M., Meier, E. A., Fredrickson, B. L., & Schultheiss, O. C. (2007). Relationship between salivary cortisol and progesterone levels in humans. Biological Psychology, 74, 104–107.

    PubMed  Article  Google Scholar 

  68. Wirth, M. M., & Schultheiss, O. C. (2006). Effects of affiliation arousal (hope of closeness) and affiliation stress (fear of rejection) on progesterone and cortisol. Hormones and Behavior, 50, 786–795.

    PubMed  Article  Google Scholar 

Download references

Acknowledgments

The authors would like to thank Lianna Burton, Thomas Butler, Brian Fredrickson, Jennifer Gabrysh, Danielle Kaplan, Aspen Lewis, and Vera Wegricht for collecting data. This research was supported by a UCLA Council on Research grant to the second author.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Diana S. Fleischman.

Appendix

Appendix

See Table 1.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Fleischman, D.S., Fessler, D.M.T. & Cholakians, A.E. Testing the Affiliation Hypothesis of Homoerotic Motivation in Humans: The Effects of Progesterone and Priming. Arch Sex Behav 44, 1395–1404 (2015). https://doi.org/10.1007/s10508-014-0436-6

Download citation

Keywords

  • Homosexual behavior
  • Homoerotic behavior
  • Affiliation
  • Progesterone
  • Priming