title: Digit ratio (2D:4D) in homosexual and heterosexual men from Austria.
abstract: Neurohormonal theories of sexual orientation emphasize the organizational effects of testosterone on the developing brain. A recent suggestion, that the ratio of the length of the 2nd and 4th digits (2D:4D) is negatively correlated with prenatal testosterone, has led to a number of studies of 2D:4D in homosexual and heterosexual men and women. The results have been mixed. In comparison to heterosexual men, mean 2D:4D in gay men has been reported to be hypermasculinized (lower 2D:4D), hypomasculinized (higher 2D:4D), or to show no significant difference. Here, we report mean 2D:4D in Austrian homosexual and heterosexual men. We found no significant difference between means for homosexual and heterosexual 2D:4D, with values for both falling between 0.96 to 0.97. There are now 6 reports of 2D:4D in heterosexual and homosexual men. Considering Caucasian men, the studies from the United States show low heterosexual mean 2D:4D, and homosexual mean 2D:4D is higher or similar to that of heterosexuals. The European studies show high heterosexual mean 2D:4D, and comparisons with homosexuals reveal the latter to have lower or similar mean 2D:4D to that of heterosexuals. We discuss these results in relation to the suggestion that mean 2D:4D in heterosexual men differs across populations but mean 2D:4D in homosexuals shows less geographical variation (the "uniform mean hypothesis"). It is concluded that more data are required to clarify whether or not there is a 2D:4D effect for sexual orientation in men.
authors.affiliation: Department of Psychology, University of Vienna, Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Voracek
authors.forename: John T
authors.initials: JT
authors.lastname: Manning
authors.forename: Ivo
authors.initials: I
authors.lastname: Ponocny
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000886:Anthropometry / Q000379:methods; D001317:Austria; D001824:Body Constitution; D005385:Fingers / Q000033:anatomy & histology*; D020010:Heterosexuality / Q000706:statistics & numerical data; D018451:Homosexuality, Male / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D009929:Organ Size; D012016:Reference Values; D012727:Sex Characteristics; D013739:Testosterone / Q000502:physiology
chemical_list: D013739:Testosterone