Archives of Sexual Behavior

, Volume 29, Issue 5, pp 463–478 | Cite as

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


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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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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