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


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.


sexual orientation homosexuality human behaviour hair-whorl orientation behaviour biology 


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Copyright information

© Indian Academy of Sciences 2004

Authors and Affiliations

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

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