Archives of Sexual Behavior

, Volume 22, Issue 3, pp 187–206 | Cite as

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

  • Frederick L. Whitam
  • Milton Diamond
  • James Martin

Abstract

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.

Key words

homosexuality twins triplets sexual orientation genetics 

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References

  1. Bailey, J. M., and Pillard R. C. (1991). A genetic study of male sexual orientation.Arch. Gen. Psychiat. 48: 1089–1096.PubMedGoogle Scholar
  2. Bouchard, T. J., Lykken, D. T., McGue, M., Segal, N. L., and Tellegen, A. (1990). Sources of human psychological differences: The Minnesota study of twins reared apart.Science 250: 223–228.PubMedGoogle Scholar
  3. Davison, K., Brierley, H., and Smith, C. (1971). A male monozygotic twinship discordant for homosexuality.Br. J. Psychiat. 118: 675–682.Google Scholar
  4. Diamond, M. (1965). A critical evaluation of the ontogeny of human sexual behavior.Quart. Rev. Biol. 40 147–175.PubMedGoogle Scholar
  5. Diamond, M. (1976). Human sexual development: Biological foundation for social development. In Beach, F. A. (ed.),Human Sexuality in Four Perspectives Johns Hopkins Press, Baltimore, MD, pp. 22–61.Google Scholar
  6. Diamond, M. (1979). Sexual identity and sex roles. In Bullough, V. (ed.),The Frontiers of Sex Research Prometheus, Buffalo, NY, pp. 33–56.Google Scholar
  7. Diamond, M. (1982). Sexual identity, monozygoyic twins reared in discordant sex roles and a BBC follow-up.Arch. Sex. Behav. 11: 181–185.PubMedGoogle Scholar
  8. Diamond, M. (1993). Homosexuality and bisexuality in different populations.Arch. Sex. Behav. 22(4).Google Scholar
  9. Diamond, M. (in press). Bisexuality: Biological aspects. In Haeberle, E. J. (ed.),Bisexualities, Walter de Gruyte, Berlin.Google Scholar
  10. Diamond, M., and Whitam, F. L. (1987). Sexuality of male twins when one or both are homosexuals. Unpublished paper presented at Eighth World Congress for Sexology, Heidelberg, Germany.Google Scholar
  11. Diamond, M., Whitam, F. L., and Dannemiller, J. E. (1987). Homosexuality in male twins. Unpublished paper presented at the International Academy of Sex Research, Tutzing, Germany.Google Scholar
  12. Eckert, E. D., Bouchard, T. J., Bohlen, J., and Heston, L. L. (1986). Homosexuality in monozygotic twins reared apart.Br. J. Psychiat. 148: 421–425.Google Scholar
  13. Friedman, R. C., Wollesen, F., and Tendler, R. (1976). Psychological development and blood levels of sex steroids in male identical twins of divergent sexual orientation.J. Nerv. Ment. Dis. 163: 282–288.PubMedGoogle Scholar
  14. Green, R., and Stoller, R. J. (1971). Two monozygotic (identical) twin pairs discordant for gender identity.Arch. Sex. Behav. 1: 321–327.Google Scholar
  15. Heston, L. L. and Shields, J. (1968). Homosexuality in twins.Arch. Gen. Psychiat. 18: 149–160.Google Scholar
  16. Jackson, D. D. (1980). Reunion of identical twins, raised apart, reveals some astonishing similarities.Smithsonian October, pp. 48–56.Google Scholar
  17. Julian, J. (1973).Social Problems Prentice-Hall, Englewood Cliffs, NJ.Google Scholar
  18. Kaij, L. (1960).Alcoholism in Twins Almqvist and Wiksell, Stockholm.Google Scholar
  19. Kallmann, F. J. (1952). Comparative twin study on the genetic aspects of male homosexuality.J. Nerv. Ment. Dis. 115: 283–298.PubMedGoogle Scholar
  20. King, M., and McDonald, E. (1992). Homosexuals who are twins: A study of 46 probands.Br. J. Psychiat. 160, 407–409.Google Scholar
  21. Kinsey, A. C., Pomeroy, W. B., and Martin, C. E. (1948).Sexual Behavior in the Human Male W. B. Saunders, Philadelphia.Google Scholar
  22. Kinsey, A. C., Pomeroy, W. B., Martin, C. E., and Gebhard, P. (1953).Sexual Behavior in the Human Female W. B. Saunders, Philadelphia.Google Scholar
  23. Klerman, G. L. (1978).Long-term treatment of affective disorders. In Lipton, M. A., DiMascio, A., and Killman, K. F. (eds.),Psychopharmacology: A Generation of Progress Raven, New York.Google Scholar
  24. Klintworth, G. K. (1962). A pair of male monozygotic twins discordant for homosexuality.J. Nerv. Ment. Dis. 135: 113–125.PubMedGoogle Scholar
  25. Melnick, M., Myrianthopolos, N. C., and Christian, J. C. (1978). The effects of chorion on variation in I.Q. in the NCPP twin population.Am J. Hum. Genet. 30: 425–433.PubMedGoogle Scholar
  26. Meskinoff, A. I., Rainer, J. D., Kolb, L. C., and Carr, A. C. (1963). Intrafamilial determinants of divergent sexual behavior in twins.Am. J. Psychiat. 119: 732–738.PubMedGoogle Scholar
  27. Nagylaki, T., and Levy, J. (1973). “Sound of one paw clapping” isn't sound.Behav. Genet. 3: 279–292.PubMedGoogle Scholar
  28. Nichols, R. C., and Bilbro, W. C. (1966). The diagnosis of twin zygosity.Acta Genet. Statist. Med. 16: 265–275.PubMedGoogle Scholar
  29. Parker, N. (1964). Homosexuality in twins: A report on three discordant pairs.Br. J. Psychiat. 119: 732–738.Google Scholar
  30. Perkins, M. W. (1973). Homosexuality in female monozygotic twins.Behav. Genet. 3: 387–388.PubMedGoogle Scholar
  31. Puterbaugh, G. (1990). Introduction. In Puterbaugh, G. (ed.),Twins and Homosexuality: A Casebook, Garland, New York, pp. xi–xvii.Google Scholar
  32. Rainer, J. D., Mesnikoff, A., Kolb, L. C., and Carr, A. (1960). Homosexuality and heterosexuality in identical twins.Psycho. Med. 22: 251–259.Google Scholar
  33. Schlegel, W. W. (1962). Die Konstitutionsbiologischen Grundagen der Homosexualitat.Z. Menschl. Vererb. Konstitutiotnslehre 36: 341–364.Google Scholar
  34. Whitam, F. L., and Diamond, M. (1985). The sexual orientation of homosexual twins. Unpublished paper presented at International Academy of Sex Research, Seattle.Google Scholar
  35. Whitam, F. L., and Diamond, M. (1986). A preliminary report on the sexual orientation of homosexual twins. Unpublished paper presented at Scientific Study of Sex, Western Region, Scottsdale, AZ.Google Scholar
  36. Whitam, F. L., Diamond, M., and Vacha, T. (1988). The sexual fantasies of male homosexual twins. Unpublished paper presented at Society for the Scientific Study of Sex, San Francisco.Google Scholar
  37. Whitam, F. L., and Mathy, R. M. (1986).Male Homosexuality in Four Societies: Brazil, Guatemala, the Philippines, and the United States Praeger, New York.Google Scholar
  38. Zuger, B. (1976). Monozygotic twins discordant for homosexuality: Report on a pair and significance of the phenomenon.Comprehen. Psychiat. 17: 661–669.Google Scholar

Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • Frederick L. Whitam
    • 1
  • Milton Diamond
    • 2
  • James Martin
    • 1
  1. 1.Department of SociologyArizona State UniversityTempeUSA
  2. 2.Department of Anatomy and Reproductive Biology, John A. Burns School of MedicineUniversity of HawaiiHonoluluUSA

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