Archives of Sexual Behavior

, Volume 45, Issue 7, pp 1705–1711 | Cite as

Heterosexual Male Carriers Could Explain Persistence of Homosexuality in Men: Individual-Based Simulations of an X-Linked Inheritance Model

Original Paper


Homosexuality has been documented throughout history and is found in almost all human cultures. Twin studies suggest that homosexuality is to some extent heritable. However, from an evolutionary perspective, this poses a problem: Male homosexuals tend to have on average five times fewer children than heterosexual males, so how can a phenomenon associated with low reproductive success be maintained at relatively stable frequencies? Recent findings of increased maternal fecundity of male homosexuals suggest that the genes responsible for homosexuality in males increase fecundity in the females who carry them. Can an increase in maternal fecundity compensate for the fecundity reduction in homosexual men and produce a stable polymorphism? In the current study, this problem was addressed with an individual-based modeling (IBM) approach. IBM suggests that male homosexuality can be maintained in a population at low and stable frequencies if roughly more than half of the females and half of the males are carriers of genes that predispose the male to homosexuality.


Homosexuality Simulation Population Genetics X-linked Sexual orientation 



I thank Lexo Gavashelishvili and David Tarkhnishvili for providing valuable suggestions on manuscript. I express my gratitude to Ryan Erickson and Cort Anderson for improving the use of English in the article. I also thank three anonymous reviewers and the Editor for their helpful comments.


  1. Bailey, J. M., Dunne, M. P., & Martin, N. G. (2000). Genetic and environmental influences on sexual orientation and its correlates in an Australian twin sample. Journal of Personality and Social Psychology, 78, 524–536.CrossRefPubMedGoogle Scholar
  2. Bailey, J. M., & Pillard, R. C. (1991). A genetic study of male sexual orientation. Archives of General Psychiatry, 48, 1089–1096.CrossRefPubMedGoogle Scholar
  3. Borrill, P. L., & Tesfatsion, L. (2011). Agent-based modeling: The right mathematics for the social sciences? In J. B. Davis & D. W. Hands (Eds.), Elgar companion to recent economic methodology (pp. 228–259). Cheltenham, UK: Edward Elgar Publishing.Google Scholar
  4. Ciani, A. C., Cermelli, P., & Zanzotto, G. (2008). Sexually antagonistic selection in human male homosexuality. PLoS One, 3(6), e2282. doi: 10.1371/journal.pone.0002282.CrossRefGoogle Scholar
  5. Ciani, A. C., Corna, F., & Capiluppi, C. (2004). Evidence for maternally inherited factors favouring male homosexuality and promoting female fecundity. Proceedings of the Royal Society of London B: Biological Sciences, 271, 2217–2221.CrossRefGoogle Scholar
  6. Ciani, A. C., & Pellizzari, E. (2012). Fecundity of paternal and maternal non-parental female relatives of homosexual and heterosexual men. PLoS One, 7(12), e51088. doi: 10.1371/journal.pone.0051088.CrossRefGoogle Scholar
  7. Diamond, M. (1993). Homosexuality and bisexuality in different populations. Archives of Sexual Behavior, 22, 291–310.CrossRefPubMedGoogle Scholar
  8. Eckert, E. D., Bouchard, T. J., Bohlen, J., & Heston, L. L. (1986). Homosexuality in monozygotic twins reared apart. British Journal of Psychiatry, 148, 421–425.CrossRefPubMedGoogle Scholar
  9. Ellis, L., Robb, B., & Burke, D. (2005). Sexual orientation in United States and Canadian college students. Archives of Sexual Behavior, 34, 569–581.CrossRefPubMedGoogle Scholar
  10. Evans, D. M., & Martin, N. G. (2000). The validity of twin studies. GeneScreen, 1(2), 77–79.CrossRefGoogle Scholar
  11. Gates, G. (2011). How many people are lesbian, gay, bisexual and transgender? Los Angeles: The Williams Institute of the University of California.Google Scholar
  12. Gavrilets, S., & Rice, W. R. (2006). Genetic models of homosexuality: Generating testable predictions. Proceedings of the Royal Society of London B: Biological Sciences, 273, 3031–3038.CrossRefGoogle Scholar
  13. Getz, W. M. (1993). Invasion and maintenance of alleles that influence mating and parental success. Journal of Theoretical Biology, 162, 515–537.CrossRefPubMedGoogle Scholar
  14. Grimm, V., & Railsback, S. F. (2013). Individual-based modeling and ecology. Princeton, NJ: Princeton University Press.Google Scholar
  15. Grulich, A. E., Visser, R. O., Smith, A., Rissel, C. E., & Richters, J. (2003). Sex in Australia: Homosexual experience and recent homosexual encounters. Australian and New Zealand Journal of Public Health, 27, 155–163.CrossRefPubMedGoogle Scholar
  16. Haldane, J. B. S., & Jayakar, S. D. (1964). Equilibria under natural selection at a sex-linked locus. Journal of Genetics, 59, 29–36.CrossRefGoogle Scholar
  17. Hamer, D. H., Hu, S., Magnuson, V. L., Hu, N., & Pattatucci, A. M. (1993). A linkage between DNA markers on the X chromosome and male sexual orientation. Science, 261, 321–327.CrossRefPubMedGoogle Scholar
  18. Heston, L. L., & Shields, J. (1968). Homosexuality in twins: A family study and a registry study. Archives of General Psychiatry, 18, 149–160.CrossRefGoogle Scholar
  19. Hutchinson, G. E. (1959). A speculative consideration of certain possible forms of sexual selection in man. American Naturalist, 93, 81–91.CrossRefGoogle Scholar
  20. Iemmola, F., & Ciani, 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.CrossRefPubMedGoogle Scholar
  21. Joseph, J. (2000). Not in their genes: A critical view of the genetics of attention-deficit hyperactivity disorder. Developmental Review, 20, 539–567.CrossRefGoogle Scholar
  22. Kallmann, F. J. (1952). Comparative twin study on the genetic aspects of male homosexuality. Journal of Nervous and Mental Disease, 115, 283–298.PubMedGoogle Scholar
  23. Kendler, K. S., Thornton, L. M., Gilman, S. E., & Kessler, R. C. (2000). Sexual orientation in a US national sample of twin and nontwin sibling pairs. American Journal of Psychiatry, 157, 1843–1846.CrossRefPubMedGoogle Scholar
  24. Kimura, M. (1962). On the probability of fixation of mutant genes in a population. Genetics, 47, 713.PubMedPubMedCentralGoogle Scholar
  25. King, M., Green, J., Osborn, D. P., Arkell, J., Hetherton, J., & Pereira, E. (2005). Family size in White gay and heterosexual men. Archives of Sexual Behavior, 34, 117–122.CrossRefPubMedGoogle Scholar
  26. Kirk, K. M., Bailey, J. M., Dunne, M. P., & Martin, N. G. (2000). Measurement models for sexual orientation in a community twin sample. Behavior Genetics, 30, 345–356.CrossRefPubMedGoogle Scholar
  27. Kirkpatrick, R. C. (2000). The evolution of human homosexual behavior. Current Anthropology, 41, 385–413.CrossRefPubMedGoogle Scholar
  28. Långström, N., Rahman, Q., Carlström, E., & Lichtenstein, P. (2010). Genetic and environmental effects on same-sex sexual behavior: A population study of twins in Sweden. Archives of Sexual Behavior, 39, 75–80.CrossRefPubMedGoogle Scholar
  29. MacIntyre, F., & Estep, K. W. (1993). Sperm competition and the persistence of genes for male homosexuality. Biosystems, 31, 223–233.CrossRefPubMedGoogle Scholar
  30. Maynard-Smith, J. M., & Slatkin, M. (1973). The stability of predator-prey systems. Ecology, 54, 384–391.CrossRefGoogle Scholar
  31. Mustanski, B. S., DuPree, M. G., Nievergelt, C. M., Bocklandt, S., Schork, N. J., & Hamer, D. H. (2005). A genomewide scan of male sexual orientation. Human Genetics, 116, 272–278.CrossRefPubMedGoogle Scholar
  32. Nash, G. (2001). The subversive male: Homosexual and bestial images on European mesolithic rock art. In L. Bevan (Ed.), Indecent exposure: Sexuality, society and the archaeological record (pp. 43–55). Glasgow, UK: Cruithne Press.Google Scholar
  33. Rice, G., Anderson, C., Risch, N., & Ebers, G. (1999). Male homosexuality: Absence of linkage to microsatellite markers at Xq28. Science, 284, 665–667.CrossRefPubMedGoogle Scholar
  34. Richardson, K., & Norgate, S. (2005). The equal environments assumption of classical twin studies may not hold. British Journal of Educational Psychology, 75, 339–350.CrossRefPubMedGoogle Scholar
  35. Rieger, G., Blanchard, R., Schwartz, G., Bailey, J. M., & Sanders, A. R. (2012). Further data concerning Blanchard’s (2011) “Fertility in the mothers of firstborn homosexual and heterosexual men” [Letter to the Editor]. Archives of Sexual Behavior, 41, 529–531.CrossRefPubMedGoogle Scholar
  36. Roughgarden, J. (2012). Individual based models in ecology: An evaluation, or how not to ruin a good thing. Paper presented at the Philosophy of Science Association Biennial Meeting, San Diego, CA. Retrieved from
  37. Sanders, A. R., Martin, E. R., Beecham, G. W., Guo, S., Dawood, K., Rieger, G., … Bailey, J. M. (2014). Genome-wide scan demonstrates significant linkage for male sexual orientation. Psychological Medicine, 45, 1379–1388.CrossRefPubMedGoogle Scholar
  38. Seligman, M. E. (2009). What you can change and what you can’t: The complete guide to successful self-improvement. New York: Vintage.Google Scholar
  39. Sell, R. L., Wells, J. A., & Wypij, D. (1995). The prevalence of homosexual behavior and attraction in the United States, the United Kingdom and France: Results of national population-based samples. Archives of Sexual Behavior, 24, 235–248.CrossRefPubMedGoogle Scholar
  40. Taylor, J. E., & Jaenike, J. (2002). Sperm competition and the dynamics of X chromosome drive: Stability and extinction. Genetics, 160, 1721–1731.PubMedPubMedCentralGoogle Scholar
  41. Taylor, J. E., & Jaenike, J. (2003). Sperm competition and the dynamics of X chromosome drive in finite and structured populations. Annales Zoologici Fennici, 40, 195–206.Google Scholar
  42. Van de Ven, P., Rodden, P., Crawford, J., & Kippax, S. (1997). A comparative demographic and sexual profile of older homosexually active men. Journal of Sex Research, 34, 349–360.CrossRefGoogle Scholar
  43. Vasey, P. L., & VanderLaan, D. P. (2007). Birth order and male androphilia in Samoan fa’afafine. Proceedings of the Royal Society of London B: Biological Sciences, 274, 1437–1442.CrossRefGoogle Scholar
  44. Vrangalova, Z., & Savin-Williams, R. C. (2010). Correlates of same-sex sexuality in heterosexually identified young adults. Journal of Sex Research, 47, 92–102.CrossRefPubMedGoogle Scholar
  45. Whitam, F. L., Diamond, M., & Martin, J. (1993). Homosexual orientation in twins: A report on 61 pairs and three triplet sets. Archives of Sexual Behavior, 22, 187–206.CrossRefPubMedGoogle Scholar
  46. Wilson, E. O. (1975). Sociobiology: The new synthesis. Cambridge, MA: Harvard University Press.Google Scholar
  47. Zietsch, B. P., Morley, K. I., Shekar, S. N., Verweij, K. J., Keller, M. C., Macgregor, S., … Martin, N. G. (2008). Genetic factors predisposing to homosexuality may increase mating success in heterosexuals. Evolution and Human Behavior, 29, 424–433.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.Institute of EcologyIlia State UniversityTbilisiGeorgia

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