Archives of Sexual Behavior

, Volume 29, Issue 5, pp 463–478

Fraternal Birth Order and Sexual Orientation in Pedophiles

  • Ray Blanchard
  • Howard E. Barbaree
  • Anthony F. Bogaert
  • Robert Dickey
  • Philip Klassen
  • Michael E. Kuban
  • Kenneth J. Zucker
Article

Abstract

Whether homosexual pedophiles have more older brothers (a higher fraternal birth order) than do heterosexual pedophiles was investigated. Subjects were 260 sex offenders (against children age 14 or younger) and 260 matched volunteer controls. The subject's relative attraction to male and female children was assessed by phallometric testing in one analysis, and by his offense history in another. Both methods showed that fraternal birth order correlates with homosexuality in pedophiles, just as it does in men attracted to physically mature partners. Results suggest that fraternal birth order (or the underlying variable it represents) may prove the first identified universal factor in homosexual development. Results also argue against a previous explanation of the high prevalence of homosexuality in pedophiles (25% in this study), namely, that the factors that determine sexual preference in pedophiles are different from those that determine sexual preference in men attracted to adults. An alternative explanation in terms of canalization of development is suggested.

birth order canalization homosexuality pedophilia phallometry sexual orientation sibling sex ratio 

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REFERENCES

  1. ACSF Investigators. (1992). AIDS and sexual behaviour in France. Nature 360: 407–409.Google Scholar
  2. Bailey, J. M., and Zucker, K. J. (1995). Childhood sex-typed behavior and sexual orientation: A conceptual analysis and quantitative review. Dev.Psychol. 31: 43–55.Google Scholar
  3. Bem, D. J. (1996). Exotic becomes erotic: A developmental theory of sexual orientation. Psych.Rev. 103: 320–335.Google Scholar
  4. Billy, J. O. G., Tanfer, K., Grady, W. R., and Klepinger, D. H. (1993). The sexual behavior of men in the United States. Fam.Plann.Perspect. 25: 52–60.PubMedGoogle Scholar
  5. Blanchard, R. (1991). Clinical observations and systematic studies of autogynephilia. J.Sex Marital Ther. 17: 235–251.PubMedGoogle Scholar
  6. Blanchard, R. (1997). Birth order and sibling sex ratio in homosexual versus heterosexual males and females. Ann.Rev.Sex Res. 8: 27–67.Google Scholar
  7. Blanchard, R., and Bogaert, A. F. (1996a). Biodemographic comparisons of homosexual and heterosexual men in the Kinsey interview data. Arch.Sex.Behav. 25: 551–579.PubMedGoogle Scholar
  8. Blanchard, R., and Bogaert, A. F. (1996b). Homosexuality in men and number of older brothers. Am.J.Psychiat. 153: 27–31.PubMedGoogle Scholar
  9. 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.PubMedGoogle Scholar
  10. Blanchard, R., and Klassen, P. (1997). H-Y antigen and homosexuality in men. J.Theor.Biol. 185: 373–378.PubMedGoogle Scholar
  11. Blanchard, R., Watson, M. S., Choy, A., Dickey, R., Klassen, P., Kuban, M., and Ferren, D. J. (1999). Pedophiles: Mental retardation, maternal age, and sexual orientation. Arch.Sex.Behav. 28: 111–127.PubMedGoogle Scholar
  12. Blanchard, R., Zucker, K. J., Bradley, S. J., and Hume, C. S. (1995). Birth order and sibling sex ratio in homosexual male adolescents and probably prehomosexual feminine boys. Dev.Psychol. 31: 22–30.Google Scholar
  13. Blanchard, R., Zucker, K. J., 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.PubMedGoogle Scholar
  14. Bogle, A. C., Reed, T., and Rose, R. J. (1994). Replication of asymmetry of a-bridge count and behavioral discordance in monozygotic twins. Behav.Genet. 24: 65–72.PubMedGoogle Scholar
  15. Bogaert, A. F. (1998). Birth order and sibling sex ratio in homosexual and heterosexual non-white men. Arch.Sex.Behav. 27: 467–473.PubMedGoogle Scholar
  16. Bogaert, A. F., Bezeau, S., Kuban, M., and Blanchard, R. (1997). Pedophilia, sexual orientation, and birth order. J.Abnorm.Psychol. 106: 331–335.PubMedGoogle Scholar
  17. Chahnazarian, A. (1988). Determinants of the sex ratio at birth: Review of recent literature. Soc.Biol. 35: 214–235.PubMedGoogle Scholar
  18. Cronk, C. E., and Reed, R. B. (1981). Canalization of growth in Down syndrome children three months to six years. Hum.Biol. 53: 383–398.PubMedGoogle Scholar
  19. Fay, R. E., Turner, C. F., Klassen, A. D., and Gagnon, J. H. (1989). Prevalence and patterns of samegender sexual contact among men. Science 243: 338–348.PubMedGoogle Scholar
  20. Freund, K. (1967). Diagnosing homo-or heterosexuality and erotic age-preference by means of a psychophysiological test. Behav.Res.Ther. 5: 209–228.PubMedGoogle Scholar
  21. Freund, K., and Blanchard, R. (1987). Feminine gender identity and physical aggressiveness in heterosexual and homosexual pedophiles. J.Sex Mar.Ther. 13: 25–34.Google Scholar
  22. Freund, K., and Blanchard, R. (1989). Phallometric diagnosis of pedophilia. J.Consult.Clin.Psychol. 57: 100–105.PubMedGoogle Scholar
  23. Freund, K., Heasman, G., Racansky, I. G., and Glancy, G. (1984). Pedophilia and heterosexuality vs. homosexuality. J.Sex Mar.Ther. 10: 193–200.Google Scholar
  24. Freund, K., Scher, H., Chan, S., and Ben-Aron, M. (1982). Experimental analysis of pedophilia. Behav.Res.Ther. 20: 105–112.PubMedGoogle Scholar
  25. Freund, K., Scher, H., and Hucker, S. (1983). The courtship disorders. Arch.Sex.Behav. 12: 369–379.PubMedGoogle Scholar
  26. Friedman, R. C. (1988). Male Homosexuality: A Contemporary Psychoanalytic Perspective, Yale University Press, New Haven, CT.Google Scholar
  27. Gebhard, P. H., Gagnon, J. H., Pomeroy, W. B., and Christenson, C. V. (1965). Sex Offenders: An Analysis of Types, Harper & Row, New York.Google Scholar
  28. Hare, E. H., and Price, J. S. (1969). Birth order and family size: Bias caused by changes in birth rate. Br.J.Psychiat. 115: 647–657.Google Scholar
  29. Hare, E. H., and Price, J. S. (1974). Birth order and birth rate bias: Findings in a representative sample of the adult population of Great Britain. J.Biosoc.Sci. 6: 139–150.Google Scholar
  30. Harris, G. T., Rice, M. E., Quinsey, V. L., Chaplin, T. C., and Earls, C. (1992). Maximizing the discriminant validity of phallometric assessment data. Psych.Assess. 4: 502–511.Google Scholar
  31. James, W. H. (1987). The human sex ratio. Part 1: A review of the literature. Hum.Biol. 59: 721–752.PubMedGoogle Scholar
  32. James, W. H. (1998). The sex ratios of the sibs of children with psychiatric diagnoses. J.Child Psychol.Psychiat. 39: 595.PubMedGoogle Scholar
  33. Johnson, A. M., Wadsworth, J., Wellings, K., Bradshaw, S., and Field, J. (1992). Sexual lifestyles and HIV risk. Nature360: 410–412.PubMedGoogle Scholar
  34. Jones, M. B., and Blanchard, R. (1998). Birth order and male homosexuality: An extension of Slater's Index. Hum.Biol.70: 775–787.PubMedGoogle Scholar
  35. Langevin, R. (1985). Introduction. In Langevin, R. (ed.), Erotic Preference, Gender Identity, and Aggression in Men: New Research Studies, Lawrence Erlbaum Associates, Hillsdale, NJ, pp. 1–13.Google Scholar
  36. Mohr, J.W., Turner, R. E., and Jerry, M. B. (1964). Pedophilia and Exhibitionism, University of Toronto Press, Toronto, Ontario, Canada.Google Scholar
  37. Paitich, D., Langevin, R., Freeman, R., Mann, K., and Handy, L. (1977). The Clarke SHQ: A clinical sex history questionnaire for males. Arch.Sex.Behav.6: 421–436.PubMedGoogle Scholar
  38. Prader, A., Tanner, J. M., and von Harnack, G. A. (1963). Catch-up growth following illness or starvation: An example of developmental canalization in man. J.Pediatr.62: 646–659.PubMedGoogle Scholar
  39. Price, J. S., and Hare, E. H. (1969). Birth order studies: Some sources of bias. Br.J.Psychiat.115: 633–646.Google Scholar
  40. Purcell, D. W., Blanchard, R., and Zucker, K. J. (in press). Birth order in a contemporary sample of gay men. Arch.Sex.Behav.Google Scholar
  41. Raymond, N. C., Coleman, E., Ohlerking, F., Christenson, G. A., and Miner, M. (1999). Psychiatric comorbidity in pedophilic sex offenders. Am.J.Psychiat.156: 786–788.PubMedGoogle Scholar
  42. Rooth, G. (1973). Exhibitionism, sexual violence and paedophilia. Br.J.Psychiat.122: 705–710.Google Scholar
  43. Rose, R. J., Reed, T., and Bogle, A. (1987). Asymmetry of a-bridge count and behavioral discordance of monozygotic twins. Behav.Genet.17: 125–140.PubMedGoogle Scholar
  44. Shapiro, B. L. (1975). Amplified developmental instability in Down's syndrome. Ann.Hum.Genet.38: 429–437.PubMedGoogle Scholar
  45. Spitzer, R. L. (1981). The diagnostic status of homosexuality in DSM-III:Areformulation of the issues. Am.J.Psychiat.138: 210–215.PubMedGoogle Scholar
  46. Sulloway, F. J. (1996). Born to Rebel: Birth Order, Family Dynamics, and Creative Lives, Pantheon Books, New York.Google Scholar
  47. Waddington, C. H. (1962). New Patterns in Genetics and Development, Columbia University Press, New York.Google Scholar
  48. Wilkins, A. S. (1997). Canalization: A molecular genetic perspective. BioEssays19: 257–262.PubMedGoogle Scholar

Copyright information

© Plenum Publishing Corporation 2000

Authors and Affiliations

  • Ray Blanchard
    • 1
    • 2
  • Howard E. Barbaree
    • 1
  • Anthony F. Bogaert
    • 3
  • Robert Dickey
    • 1
  • Philip Klassen
    • 1
  • Michael E. Kuban
    • 4
  • Kenneth J. Zucker
    • 1
  1. 1.Centre for Addiction and Mental Health, Department of Psychiatry, Faculty of MedicineUniversity of TorontoTorontoCanada
  2. 2.CAMH—Clarke DivisionTorontoCanada
  3. 3.Health Studies ProgramBrock UniversityCanada
  4. 4.Centre for Addiction and Mental HealthTorontoCanada

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