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Finger-length ratios and sexual orientation

Measuring people's finger patterns may reveal some surprising information.


Animal models have indicated that androgenic steroids acting before birth might influence the sexual orientation of adult humans. Here we examine the androgen-sensitive pattern of finger lengths1, and find evidence that homosexual women are exposed to more prenatal androgen than heterosexual women are; also, men with more than one older brother, who are more likely than first-born males to be homosexual in adulthood2, are exposed to more prenatal androgen than eldest sons. Prenatal androgens may therefore influence adult human sexual orientation in both sexes, and a mother's body appears to ‘remember’ previously carried sons, altering the fetal development of subsequent sons and increasing the likelihood of homosexuality in adulthood.

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  1. 1

    Manning, J. T., Scutt, D., Wilson, J. & Lewis-Jones, D. I. Hum. Reprod. 13, 3000–3004 ( 1998).

  2. 2

    Blanchard, R. Annu. Rev. Sex Res. 8, 27–67 (1997).

  3. 3

    Breedlove, S. M., Cooke, B. M. & Jordan, C. L. Brain Behav. Evol. 54, 8– 14 (1999).

  4. 4

    Manning, J. T., Trivers, R .L., Singh, D. & Thornhill, R. Nature 399, 214–215 ( 1999).

  5. 5

    McFadden, D. & Pasanen, E. Proc. Natl Acad. Sci. USA 95, 2709–2713 (1998).

  6. 6

    James, W. H. Hum. Biol. 59, 721–752 ( 1987).

  7. 7

    Bogaert, A. F. Behav. Neurosci. 111, 1395–1397 (1997).

  8. 8

    Bailey, J. M. & Pillard, R. C. Arch. Gen. Psychiatry 48, 1089–1096 (1991).

  9. 9

    Hamer, D. D., Hu, S., Magnuson, V. L., Hu, N. & Pattatucci, A. M. L. Science 261, 321– 327 (1993).

  10. 10

    Gorman, M. R. Persp. Biol. Med. 38, 61–81 (1994).

  11. 11

    Brodie, H. K. H. et al. Am. J. Psychiatry 131, 82– 83 (1974).

  12. 12

    Mayer-Bahlburg, H. F. L. Progr. Brain Res. 61, 375–398 (1984).

  13. 13

    Bogaert, A. F. & Hershberger, S. Arch. Sexual Behav. 28, 213–221 ( 1999).

  14. 14

    McFadden, D. & Champlin, C. A. J. Ass. Res. Otolaryngol. (in the press).

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Correspondence to S. Marc Breedlove.

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Figure 1: Finger-length patterns vary with gender, sexual orientation and birth order.


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