Archives of Sexual Behavior

, Volume 29, Issue 1, pp 1–34 | Cite as

Homosexuality, Birth Order, and Evolution: Toward an Equilibrium Reproductive Economics of Homosexuality

  • Edward M. Miller
Article

Abstract

The survival of a human predisposition for homosexuality can be explained by sexual orientation being a polygenetic trait that is influenced by a number of genes. During development these shift male brain development in the female direction. Inheritance of several such alleles produces homosexuality. Single alleles make for greater sensitivity, empathy, tendermindedness, and kindness. These traits make heterosexual carriers of the genes better fathers and more attractive mates. There is a balanced polymorphism in which the feminizing effect of these alleles in heterosexuals offsets the adverse effects. (on reproductive success) of these alleles' contribution to homosexuality. A similar effect probably occurs for genes that can produce lesbianism in females. The whole system survives because it serves to provide a high degree of variability among the personalities of offspring, providing the genotype with diversification and reducing competition among offspring for the same niches. An allele with a large effect can survive in these circumstances in males, but it is less likely to survive in females. The birth order effect on homosexuality is probably a by-product of a biological mechanism that shifts personalities more in the feminine direction in the later born sons, reducing the probability of these sons engaging in unproductive competition with each other.

homosexuality birth order evolution genetics 

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REFERENCES

  1. Alexander, J. E., and Sufka, K. J. (1993). Cerebral lateralization in homosexual males? A preliminary EEG investigation. Int.J.Psychophysiol.15: 269–274.Google Scholar
  2. Allen, L. S., and Gorski, R. A. (1992). Sexual orientation and the size of the anterior commissure in the human brain. Proc.Natl.Acad.Sci.USA.89: 7199–7202.Google Scholar
  3. Bailey, J. M., and Martin, N. G. (1995). A twin registry study of sexual orientation. Poster presentation at the International Academy of Sex Research, 21st Annual Meeting, Provincetown, MA.Google Scholar
  4. Bailey, J. M., and Pillard, R. C. (1991).Agenetic study of male sexual orientation. Arch.Gen.Psychiatry48: 1089–1096.Google Scholar
  5. Bailey, J. M., and Zucker, K. J. (1995). Childhood sex-type behavior and sexual orientation: A conceptual analysis and quantitative review. Dev.Psychol.31: 43–55.Google Scholar
  6. Bailey, J. M., Pillard, R. C., Neale, M. C., and Agyei, Y. (1993). Heritable factors influence sexual orientation in women. Arch.Gen.Psychiatry50: 217–223.Google Scholar
  7. Bailey, J. M., Finkel, E., Blackwelder, K., and Bailey, T. (1996). Masculinity, feminity, and sexual orientation (unpublished manuscript).Google Scholar
  8. Bailey, J. M., Kim, P., Hills, A., and Linsenmeier, J. (1999). Butch, femme, or straight-acting? Partner preferences of gay men and lesbians. J.Pers.Soc.Psychol.73: 960–973.Google Scholar
  9. Bailey, J. M., Dunne, M. P., and Martin, N. G. (in press). Genetic and environmental influences on sexual orientation and its correlates in an Australian twin sample. J.Pers.Soc.Psychol.Google Scholar
  10. Baker, R., and Bellis, M. (1995.) Human Sperm Competition, Chapman and Hall, London.Google Scholar
  11. Bakker, J., and Slob, A. K. (1997). Sexual differentation of the brain and partner preferences in the male rat: Behavioral, neuroanatomical and neuroimmunocytochemical studies. In Ellis, L., and Ebertz, L. (eds.), Sexual Orientation: Toward Biological Understanding, Praeger, Westport, CT, pp. 91–106.Google Scholar
  12. Beer, J., and Horn, J. M. (1999). The influence of rearing order on personality development within two adoption cohorts. J.Personality(in press).Google Scholar
  13. Bell, A. P., and Weinberg, M. (1978). Homosexualities: A Study of Diversity Among Men and Women, Simon and Schuster, New York.Google Scholar
  14. Bell, A. P., Weinberg, M., and Hammersmith, S. (1981). Sexual Preference: Its Development in Men and Women, Indiana University Press, Bloomington.Google Scholar
  15. Bianchi, D.W., Zickwolf, G. K., Weil, G. J., and Sylvester, S. (1996). Male fetal progenitor cells persist in maternal blood for as long as 27 years postpartum. Proc.Natl.Acad.Sci.USA93: 705–708.Google Scholar
  16. Blanchard, R. (1997). Birth order and sibling sex ratio in homosexual versus heterosexual males and females. Annu.Rev.Sex Res.8: 27–67.Google Scholar
  17. Blanchard, R., and Bogaert, A. F. (1996a). Biodemographic comparisons of homosexual and heterosexual men in the Kinsey interview data. Am.J.Psychiatry153: 27–31.Google Scholar
  18. Blanchard, R., and Bogaert, A. F. (1996b). Homosexuality in men and number of older brothers. Arch.Sex.Behav.25: 545–573.Google Scholar
  19. Blanchard, R., and Bogaert, A. F. (1998). Birth order in homosexual versus heterosexual sex offenders against children, pubescents, and adults. Arch.Sex.Behav.27: 595–603.Google Scholar
  20. Blanchard, R., and Klassen, P. (1997). H-Y antigen and homosexuality in men. J.Theor.Biol.185: 373–378.Google Scholar
  21. Blanchard, R., and Sheridan, P. (1992a). Proportion of unmarried siblings of homosexual and nonhomosexual gender-dysphoric patients. Can.J.Psychiatry37: 163–167.Google Scholar
  22. Blanchard, R., and Sheridan, P. (1992b). Sibship size, sibling sex ratio, birth order, and parental age in homosexual and nonhomosexual gender dysphorics. J.Nerv.Ment.Dis.180: 40–47.Google Scholar
  23. Blanchard, R., and Zucker, K. (1994). Reanalysis of Bell, Weinberg, and Hammersmith's data on birth order, sibling sex ratio, and parental age in homosexual men. Am.J.Psychiatry151: 1375–1376.Google Scholar
  24. Blanchard, R., Zucker, K., Bradley, S. J., and Hume, C. (1995a). Birth order and sibling sex ratio in homosexual male adolescents and probably prehomosexual feminine boys. Dev.Psychol.31:22–30.Google Scholar
  25. Blanchard, R., Zucker, Cohen-Kettenis, P., Gooren, L., and Bailey, J. M. (1995b). Birth order and sibling sex ratio in two samples of Dutch gender-dysphoric homosexual males. Arch.Sex.Behav. 25: 495–514.Google Scholar
  26. Blanchard, R., Zucker, K., Siegelman, M., Dickey, R., and Klassen, P. (1998). The relation of birth order to sexual orientation in men and women. J.Biosoc.Sci. 30: 511–519.Google Scholar
  27. Bogaert, A. F., and Blanchard, R. (1996). Physical development and sexual orientation in men: Height, weight, and age of puberty differences. Person.Indiv.Diff.21: 77–84.Google Scholar
  28. Brim, O. G. (1958). Family structure and sex role learning by children: A further analysis of Helen Koch's data. Sociometry21: 1–16.Google Scholar
  29. Buss, D. M. (1989). The Evolution of Desire, Basic Books, New York.Google Scholar
  30. Buss, D. M. (1994). Sex differences in human mate preference: Evolutionary hypothesises tested in cultures. Behav.Brain Sci.12: 1–49.Google Scholar
  31. Buss, D. M., and Barnes, M. (1994). Preferences in human mate selection. J.Pers.Soc.Psychol.50:559–570.Google Scholar
  32. Chung, Y. B., and Harmon, L. W. (1994). The career interests and aspirations of gay men: How sex role orientation is related. J.Vocat.Behav.45: 223–239.Google Scholar
  33. Cohen, D. B. (1999). Stranger in the Nest: Do Parents Really Shape Their Child's Personality, Intelligence, or Character?John Wiley & Sons, New York, p. 28.Google Scholar
  34. Dorner, G., Rohde W., Stahl, F., et al.(1975). A neuroendocrine predisposition for homosexuality in men. Arch.Sex.Behav.4: 1–8.Google Scholar
  35. Dorner, G., Schenck, B., Shmiedel, B., and Ahrens L. (1983). Stressful events in prenatal life of bi and homosexual men. Exp.Clin.Endocrinol Diabetes.81: 83–87.Google Scholar
  36. Eaton, W., and Dureski, C. M. (1986). Parent and actometer measures of motor activity in the young enfant. Infant Behav.Dev.9: 383–393.Google Scholar
  37. Eaton, W., Chipperfield, J., and Singbeil, C. (1989). Birth order and activity level in children. Dev.Psychol.25: 668–672.Google Scholar
  38. Eaves, L. J., Eysenck, H. J., and Martin, N. G. (1989). Genes, Culture, and Personality, Academic Press, London.Google Scholar
  39. Ellis, L. (1997). Perinatal influences on behavior and health, with special emphasis on sexual orientation and other sex-linked behavior. In Ellis, L., and Ebertz, L. (eds.), Sexual Orientation: Toward Biological Understanding, Praeger, Westport, CT, pp. 71–88.Google Scholar
  40. Ellis, L., and Ames, M.A. (1987). Neurohormonal functioning and sexual orientation: A theory of homosexuality-heterosexuality. Psychol.Bull.101: 233–258.Google Scholar
  41. Ellis, L., and Ebertz, L. (eds.) (1997). Sexual Orientation: Toward Biological Understanding, Praeger, Westport, CT.Google Scholar
  42. Ellis, L., Ames, M. A., Peckham, W., and Burke, D. (1987). Sexual orientation of human offspring may be altered by severe maternal stress during pregnancy. J.Sex Res.25: 152–157.Google Scholar
  43. Ellis, L., Hoffman, H., and Burke, D. M. (1990). Sex, sexual orientation and criminal and violent behavior. Person.Indiv.Diff.11: 1207–1212.Google Scholar
  44. Eysenck, H. J., and Wilson, G. (1979). The Psychology of Sex, J. M. Dent and Sons, London.Google Scholar
  45. Fauls, L. B., and Smith, W. D. (1956). Sex role learning of five-year-olds. J.Genet.Psychol.89:105–117.Google Scholar
  46. Gallup, G., and Suarez, S. (1983). Homosexuality as a by-product of selection for optimal heterosexual strategies. Perspect.Biol.Med.26: 315–322.Google Scholar
  47. Gandelman, R. (1992). Psychobiology of Behavioral Development, Oxford University Press, Oxford.Google Scholar
  48. Getz, W. (1993). Invasion and maintenance of alleles that influence reproductive success. J.Theor.Biol.162: 515–537.Google Scholar
  49. Gettelman, T. E., and Thomas, J. K. (1993). Actual differences and stereotypical perceptions in body image and eating disturbance: A comparison of male and female heterosexual and homosexual samples. Sex Roles29: 545–562.Google Scholar
  50. Gladue, B. A., Green, R., and Hellman, R. E. (1984). Neuroendocrine response to estrogen and sexual orientation. Psychoneurorendocrinology20: 475–485.Google Scholar
  51. Gladue, B. A., Beatty, W.W., Larson, J., and Staton, R. D. (1990). Sexual orientation and spatial ability in men and women. Psychobiology18(1): 101–108.Google Scholar
  52. Goode, E., and Troiden, R. R. (1980). Correlates and accompaniments of promiscuous sex among male homosexuals. Psychiatry43: 51–59.Google Scholar
  53. Gooren, L. J. G. (1986). The neuroendocrine response of luteinizing hormone to estrogen administration in heterosexual, homosexual, and transsexual subjects. J.Clin.Endocrinol.Metab.63: 588–593.Google Scholar
  54. Gorman, M. R. (1994). Male homosexual desire: Neurological investigations and scientific bias. Perspect.Biol.Med.38(1).Google Scholar
  55. Green, R. (1987). The “Sissy Boy Syndrome” and the Development of Homosexuality, Yale University Press, New Haven, CT.Google Scholar
  56. Guadio, R. P. (1994). Sounding gay: Pitch properties in the speech of gay and straight men. Am.Speech69(1).Google Scholar
  57. Hall, J. A. Y., and Kimura, D. (1994). Dermatoglyphic asymmetry and sexual orientation in men. Behav.Neurosci.108: 1203–1206.Google Scholar
  58. Hall, J. A. Y., and Kimura, D. (1995). Sexual orientation and performance on sexually dimorphic motor tasks. Arch.Sex.Behav.24: 395–407.Google Scholar
  59. Halpern, D. F., and Crothers, M. (1997). Sex, sexual orientation, and cognition. In Ellis, L., and Ebertz, L. (eds.), Sexual Orientation: Toward Biological Understanding, Praeger, Westport CT, pp. 181–197.Google Scholar
  60. Hamer, D., and Copeland, P. (1994). The Science of Desire, Simon and Schuster, New York.Google Scholar
  61. Hamer, D., and Copeland, P. (1998). Living with Our Genes, Doubleday, New York.Google Scholar
  62. Hamer, D., Hu, S., Magnuson, V., Hu, N. and Pattatuci, A. (1993). A linkage between DNA markers on the X chromosome and male sexual orientation. Science261: 321–327.Google Scholar
  63. Hu, S., Pattatuci, A., Patterson, C., Li, L., Fulker, D. W., Cherny, S., Kruglyak, L., and Hamer, D. (1995). Linkage between sexual orientation and chromosome Xq28 in males but not in females. Nature Genet.11: 248–256.Google Scholar
  64. Jacklin, C. N., Maccoby, E., and Doering, C. H. (1983). Neonatal sex-steroid hormones and timidity in 6–18–month-old boys and girls. Dev.Psychobiol.16(3): 163–168.Google Scholar
  65. Jones, M. B., and Blanchard, R., (1998). Birth order and male homosexuality: Extension of Slater's index. Hum.Biol.70: 775–787.Google Scholar
  66. Kallmann, F. J. (1952). Comparative twin studies on the genetic aspects of male homosexuality. J.Nerv.Ment.Dis.115: 283–298.Google Scholar
  67. Laumann, E., Gagnon, J. H., Michael R. T., and Michaels, S. (1994). The Social Organization of Sexuality: Sexual Practices in the United States, University of Chicago Press, Chicago.Google Scholar
  68. LeVay, S. (1991). A difference in hypothalamic structure between heterosexual and homosexual men. Science253: 1034–1037.Google Scholar
  69. LeVay, S. (1993). The Sexual Brain, MIT Press, Cambridge, MA.Google Scholar
  70. LeVay, S. (1996). Queer Science: The Use and Abuse of Research into Homosexuality, MIT Press, Cambridge, MA.Google Scholar
  71. Maccoby, E. E., Doering, C. H., Jacklin, C. N., and Kraemer,H. (1979). Concentrations of sex hormones in umbilical cord blood: Their relation to sex and birth order in infants. Child Dev. 50: 632–642.Google Scholar
  72. MacIntrye, F., and Estep, K. W. (1993). Sperm competition and the persistence of the genes for male homosexuality. Biosystems31: 223–233.Google Scholar
  73. McCormick, C. M., and Witelson, S. F. (1991). A cognitive profile of homosexual men compared to heterosexual men and women. Psychoneurorendocrinology16: 459–473.Google Scholar
  74. McFadden, D., and Pasanen, E. G. (1998). Comparison of the auditory systems of heterosexuals and homosexuals: Click-evoked otoacoustic emissions. Proc.Natl.Acad.Sci.USA95: 2709–2713.Google Scholar
  75. McGuire, T. R. (1995). Is homosexuality genetic? A critical review and some suggestions. J.Homosex.28(1/2): 115–144.Google Scholar
  76. McKnight, J. (1997). Straight Science: Homosexuality, Evolution and Adaptation, Routledge, New York.Google Scholar
  77. Mellen, S. L. (1981). The Evolution of Love, Freeman, San Francisco.Google Scholar
  78. Miller, E. M. (1994). Prenatal sex hormone transfer: A reason to study opposite-sex twins. Person.Indiv.Diff.17: 511–529.Google Scholar
  79. Miller, E. M. (1997a). Could nonshared environmental variance have evolved to assure diversification through randomness? Evol.Hum.Behav.18: 195–221.Google Scholar
  80. Miller, E. M. (1997b). Evidence from opposite-sex twins for the effects of prenatal sex hormones. In Ellis, L., and Ebertz, L. (eds.), Males, Females, and Behavior: Toward Biological Understanding, Praeger, Westport, CT.Google Scholar
  81. Moran, P. A. P. (1972). Familial effects in schizophrenia and homosexuality. Aust.N.Z.J.Psychiatry6: 116–119.Google Scholar
  82. Murray, S. O. (1991). Homosexual occupations in Meso-America. J.Homosex.21: 57–65.Google Scholar
  83. Perkins, M. W. (1981). Female homosexuality and body build. Arch.Sex.Behav.10: 337–345.Google Scholar
  84. Pillard, R. C. (1991). Masculinity and femininity in homosexuality: “Inversion” revisited. In Gonsiorek, J. C., and Weinrich, J. D. (eds.), Homosexuality: Research Implications for Public Policy. Sage, Newbury Park, CA, pp. 32–43.Google Scholar
  85. Pillard, R. C., and Weinrich, J. D. (1986). Evidence of familial nature of male homosexuality. Arch.Gen.Psychiatry43: 808–12.Google Scholar
  86. Pillard, R. C., and Bailey, J. M. (1998). Human sexual orientation has a heritable component. Hum.Biol.347–365.Google Scholar
  87. Plomin, R., Chipuer, H. M., and Neiderhiser, J.M. (1994). Behavior genetic evidence for the importance of nonshared environment. In Hetherington, E. M., Reiss, D., and Plomin, R. (eds.), Separate SocialWorlds of Siblings: The Impact of Nonshared Environment on Development, Lawrence Erlbaum, Hillsdale, NJ.Google Scholar
  88. Prener, A., Hsieh, C., Engholm, G., Trichopoulos, D., and Jensen, O. (1992). Birth order and risk of testicular cancer. Cancer Causes Control3: 265–272.Google Scholar
  89. Reite, M., Scheeder, J., Richardson, D., and Teale, P. (1995). Cerebral laterality in homosexual males: Preliminary communication using magnetoencephalography. Arch.Sex.Behav.24: 585–593.Google Scholar
  90. Rogers, S. M., and Turner, C. F. (1991). Male-male sexual contact in the USA: Findings from five sample surveys, 1970–1990. J.Sex Res.28(4): 491–519.Google Scholar
  91. Rowe, D. C. (1994). The Limits of Family Influence: Genes, Experience, and Behavior, Guilford, New York.Google Scholar
  92. Saghir, M. T., and Robins, E. (1973). Male and Female Homosexuality, Williams and Wilkins, Baltimore.Google Scholar
  93. Salais, D., and Foscher, R. B. (1995). Sexual preference and altruism. J.Homosex.28: 185–196.Google Scholar
  94. Schlegel, W. S. (19xx). Die Sexualinstinkte de Menschen, Tutten Verlag, Munich.Google Scholar
  95. Siever, M. D. (1994). Sexual orientation and gender as factors in socioculturally acquired vulnerability to body dissatisfaction and eating disorders. J.Consult.Clin.Psychol.62: 252–260.Google Scholar
  96. Spence, J. T., and Helmreich, R. L. (1978). Masculinity and Feminity, University of Texas Press, Austin.Google Scholar
  97. Sprecher, S. (1989). The importance to males and females of physical attractiveness, earnings potential, and expressiveness in initial attraction. Sex Roles21: 591–605.Google Scholar
  98. Sprecher, S., Sullivan, Q., and Hartfield, E. (1994). Mate selection preferences: Gender differences examined in a national sample. J.Pers.Soc.Psychol.66: 1074–1080.Google Scholar
  99. Sulloway, F. J. (1996). Born to Rebel: Birth Order, Family Dynamics, and Creative Lives, Pantheon Books, New York.Google Scholar
  100. Sundet, J. M., Kvalem, I. L., Magnus, P., and Bakketeig, L. S. (1988). Prevalence of risk-prone behavior in the central population of Norway. In Fleming, A. F., Carballo, M., and Fitzsimons, D. F. (eds.), The Global Impact of AIDS, Alan R. Liss, London.Google Scholar
  101. Swaab, D. F., and Hofman, M. A. (1990). An enlarged suprachiasmatic nucleus in homosexual men. Brain Res.537: 141–148.Google Scholar
  102. Swaab, D. F., and Hofman, M. A. (1995). Sexual differentiation in the human hypothalamus in relation to gender and sexual orientation. Trends Neurosci.18: 264–270.Google Scholar
  103. Swaab, D. F., Slob, A. K., Houtsmuller, E. J., Brand, T., and Zhou, J. N. (1995). Increased number of vasopressin neurons in the suprachiasmatic nucleus (SCN) of “bisexual” adult male rats following perinatal treatment with the aromatase blocker ATD. Dev.Brain Res.85: 273–279.Google Scholar
  104. Swaab, D. F., Zhou, J. N., Fodor, M., and Jofman, M. A. (1997). Sexual differentiation of the human hypothalamus: Differences according to sex, sexual orientation, and transsexuality. In Ellis, L., and Ebertz, L. (eds.), Sexual Orientation: Toward Biological Understanding, Praeger, Westport, CT, pp. 129–150.Google Scholar
  105. Symons, D. (1990). The Evolution of Human Sexuality, Oxford University Press, New York.Google Scholar
  106. Tuttle, G. E., and Pillard, R. C. (1991). Sexual orientation and cognitive abilities. Arch.Sex.Behav.13: 427–439.Google Scholar
  107. Van de Ven, P., Rodden, P., Crawford, J., and Kippax, S. (1997). A comparative demographic and sexual profile of older homosexually active men. J.Sex Res.34: 349–360.Google Scholar
  108. Wegesin, D. J. (1998). Event-related potentials in homosexual and heterosexual men and women: Sex-dimorphic patterns in verbal asymmetries and mental rotation. Brain Cogn.36: 73–92.Google Scholar
  109. Weinrich, J. D. (1976). Human Reproductive Strategies(Doctoral dissertation, Harvard University), University Microfilms No. 77–8348.Google Scholar
  110. Weinrich, J. D. (1987). Sexual Landscapes, Scribner's Sons, New York.Google Scholar
  111. Wellings, K., Field, J., Johnson, A., and Wadsworth, J. (1994). Sexual Behavior in Britain., Penguin Books, New York.Google Scholar
  112. Werner, D. (1998). On the evolution and cross-cultural variation in male homosexuality [Sobre a evolu¸cïo e varia¸cïo cultural na homossexualidade masculina]. In Pedro, J. M., and Grossi, M. P., (orgs.), Masculino, Feminino Plural, Mulheres, Florian´opolis, pp.99–129.Google Scholar
  113. Whitam, F. L., Diamond, M., and Martin, J. (1993). Homosexual orientation in twins: A report on 61 pairs and 3 triplet sets. Arch.Sex.Behav.22: 187–206.Google Scholar
  114. Wilson, E. O. (1975). Sociobiology: The New Synthesis, Harvard University Press, Cambridge, MA.Google Scholar
  115. Zucker, K. J., and Bradley, S. (1995). Gender Identity Disorder and Psychosexual Problems in Children and Adults, Guilford Press, New York.Google Scholar
  116. Zucker, K. J., Green, R., Coates, S., Zuger, B., Cohen-Kettenis, P. T., Zecca, G. M., Lertora, V., Money, J., Hahn-Burke, S., Bradley, S. J., and Blanchard, R. (1997). Sibling sex ratio of boys with gender identity disorder. J.Child Psychol.Psychiatry38: 543–551.Google Scholar

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© Plenum Publishing Corporation 2000

Authors and Affiliations

  • Edward M. Miller
    • 1
  1. 1.Department of Economics and FinanceUniversity of New OrleansNew Orleans

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