Digit ratio (2D:4D) in homosexual and heterosexual men from Austria

Arch Sex Behav. 2005 Jun;34(3):335-40. doi: 10.1007/s10508-005-3122-x.

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.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Analysis of Variance
  • Anthropometry / methods
  • Austria
  • Body Constitution
  • Fingers / anatomy & histology*
  • Heterosexuality* / statistics & numerical data
  • Homosexuality, Male* / statistics & numerical data
  • Humans
  • Male
  • Organ Size
  • Reference Values
  • Sex Characteristics*
  • Testosterone / physiology

Substances

  • Testosterone