Journal of Genetics

, Volume 83, Issue 3, pp 251–255 | Cite as

Excess of counterclockwise scalp hair-whorl rotation in homosexual men

  • Amar J. S. Klar
Research Article

Abstract

While most men prefer women as their sexual partners, some are bisexual and others are homosexuals. It has been debated for a long time whether a person’s sexual preference is innate, learned, or due to a combination of both causes. It was recently discovered that the human right-versus-left-hand use preference and the direction of scalp hair-whorl rotation develop from a common genetic mechanism. Such a mechanism controls functional specialization of brain hemispheres. Whether the same mechanism specifying mental makeup influences sexual preference was determined here by comparing hair-whorl rotation in groups enriched with homosexual men with that in males at large. Only a minority of 8.2% (n = 207) unselected ‘control’ group of males had counterclockwise rotation. In contrast, all three samples enriched with homosexual men exhibited highly significant (P< 0.0001), 3.6-fold excess (29.8%,n = 272) counterclockwise rotation. These results suggest that sexual preference may be influenced in a significant proportion of homosexual men by a biological/genetic factor that also controls direction of hair-whorl rotation.

Keywords

sexual orientation homosexuality human behaviour hair-whorl orientation behaviour biology 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bailey J. M. 1989 A test of the maternal stress hypothesis for male homosexuality.Behav. Genet. 19, 744.Google Scholar
  2. Bailey J. M. and Pillard R. C. 1991 A genetic study of male sexual orientation.Arch. Gen. Psychiatry 48, 1089–1096.PubMedGoogle Scholar
  3. Bailey J. M., Pillard R. C., Neale M. C. and Agyei Y. 1993 Heritable factors influence sexual orientation in women.Arch. Gen. Psychiatry 50 217–223.PubMedGoogle Scholar
  4. Bailey J. M., Pillard R. C., Dawood K., Miller M. B., Farrer L. A., Trivedi S. and Murphy R. L. 1999 A family history study of male sexual orientation using three independent samples.Behav. Genet. 29, 79–86.PubMedCrossRefGoogle Scholar
  5. Banks A. and Gartrell N. K. 1995 Hormones and sexual orientation: a questionable link.J. Homosex. 28, 247–268.PubMedCrossRefGoogle Scholar
  6. Bocklandt S. and Hamer D. H. 2003 Beyond hormones: a novel hypothesis for the biological basis of male sexual orientation.J. Endocrinol Invest. 26, 8–12.PubMedGoogle Scholar
  7. Bogaert A. F. and Blanchard R. 1996 Handedness in homosexual and heterosexual men in the Kinsey interview data.Arch. Sex. Behav. 25, 373–378.PubMedCrossRefGoogle Scholar
  8. Geschwind D. H., Miller B. L., DeCarli C. and Carmelli D. 2002 Heritability of lobar brain volumes in twins supports genetic models of cerebral laterality and handedness.Proc. Natl. Acad. Sci. USA 99, 3176–3181.PubMedCrossRefGoogle Scholar
  9. Gotestam K. O., Coates T. J. and Ekstrand M. 1992 Handedness, dyslexia and twinning in homosexual men.Int. J. Neurosci. 63, 179–186.PubMedGoogle Scholar
  10. Hall J. C. 2002 Courtship lite: a personal history of reproductive behavioral neurogenetics in Drosophila.J. Neurogenet. 16, 135–163.PubMedCrossRefGoogle Scholar
  11. Halpern D. F. and Cass M. 1994 Laterality, sexual orientation, and immune system functioning: is there a relationship?Int. J. Neurosci. 77, 167–180.PubMedCrossRefGoogle Scholar
  12. Hamer D. H., Hu S., Magnuson V. L., Hu N. and Pattatucci A. M. 1993 A linkage between DNA markers on the X chromosome and male sexual orientation.Science 261, 321–327.PubMedCrossRefGoogle Scholar
  13. Holtzen D. W. 1994 Handedness and sexual orientation.J. Clin. Exp. Neuropsychol. 16, 702–712.PubMedGoogle Scholar
  14. Hu S., Pattatucci A. M., Patterson C., Li L., Fulker D. W., Cherny S. S., Kruglyak L. and Hamer D. H. 1995 Linkage between sexual orientation and chromosome Xq28 in males but not in females.Nat. Genet. 11, 248–256.PubMedCrossRefGoogle Scholar
  15. Klar A. J. 2003 Human handedness and scalp hair-whorl direction develop from a common genetic mechanism.Genetics 165, 269–276.PubMedGoogle Scholar
  16. Lalumiere M. L., Blanchard R. and Zucker K. J. 2000 Sexual orientation and handedness in men and women: a metaanalysis.Psychol. Bull. 126, 575–592.PubMedCrossRefGoogle Scholar
  17. Lippa R. A. 2003 Handedness, sexual orientation, and genderrelated personality traits in men and women.Arch. Sex. Behav. 32, 103–114.PubMedCrossRefGoogle Scholar
  18. McCormick C. M., Witelson S. F. and Kingstone E. 1990 Lefthandedness in homosexual men and women: neuroendocrine implications.Psychoneuroendocrinology 15, 69–76.PubMedCrossRefGoogle Scholar
  19. Mustanski B. S., Chivers M. L. and Bailey J. M. 2002a A critical review of recent biological research on human sexual orientation.Annu. Rev. Sex Res. 13, 89–140.PubMedGoogle Scholar
  20. Mustanski B. S., Bailey J. M. and Kaspar S. 2002 Dermatoglyphics, handedness, sex, and sexual orientation.Arch. Sex. Behav. 31, 113–122.PubMedCrossRefGoogle Scholar
  21. Pillard R. C. and Weinrich J. D. 1986 Evidence of familial nature of male homosexuality.Arch. Gen. Psychiatry 43, 808–812.PubMedGoogle Scholar
  22. Pollard I. 1996 Preconceptual programming and sexual orientation: a hypothesis.J. Theor. Biol. 179, 269–273.PubMedCrossRefGoogle Scholar
  23. Rice G., Anderson C., Risch N. and Ebers G. 1999 Male homosexuality: absence of linkage to microsatellite markers at Xq28.Science 284, 665–667.PubMedCrossRefGoogle Scholar
  24. Satz P., Miller E. N., Selnes O., Van Gorp W., D’Elia L. F. and Visscher B. 1991 Hand preference in homosexual men.Cortex 27, 295–306.PubMedGoogle Scholar

Copyright information

© Indian Academy of Sciences 2004

Authors and Affiliations

  • Amar J. S. Klar
    • 1
  1. 1.IjamsvilleMDUSA

Personalised recommendations