Handedness, sexual orientation, and somatic markers for prenatal androgens: Are southpaws really that gay?

ABSTRACT

Background: Some evidence suggests that prenatal androgens influence both handedness and sexual orientation. This study sought to clarify how androgens, handedness, and sexual orientation are interrelated. Methods: Data were obtained from large samples of students enrolled at universities in Malaysia and the US, including self-reported information on handedness, sexual orientation, and five somatic markers of prenatal androgen exposure (2D:4D, height, strength, muscularity, and athletic ability). Factor analysis of these somatic markers yielded two factors: a muscular coordination and a bone growth factor. Results: In women, but not in men, ambidextrousness was more prevalent among those with homosexual tendencies. Modest and often complex associations were found between the androgen factors and handedness. Clear links between the androgen factors and sexual orientation were found, especially for muscular coordination. For males and females, intermediate sex-typical androgen exposure was associated with heterosexual preferences. Conclusions: Ambidextrousness appears to be somewhat more common among females with homosexual tendencies, but left-handedness is nearly as strongly associated with heterosexual preferences, particularly in males, as is right-handedness. Factors indicative of prenatal androgen exposure are associated with sexual orientation in theoretically predictable ways, especially for muscular coordination, but associations between prenatal androgens and handedness are complex.

KEYWORDS:

• Handedness
• sexual orientation
• 2D:4D
• adult height
• muscularity
• androgen exposure

Acknowledgements

The following individuals assisted in recruiting research participants for this study: Drew H. Bailey, David Geary, Richard D. Hartley, Richard Lippa, Emi Prihatin, Anthony Walsh, and Alan Widmayer. Michael Ashton provided help with the statistical analyses.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Funding for the collection of data utilized in this study was provided in part by a research grant from the University of Malaya to its Department of Anthropology and Sociology (number RG143-10HNE) while the first author was a visiting professor in the department.