title: Are 2D:4D finger-length ratios related to sexual orientation? Yes for men, no for women.
abstract: The ratio of index and ring finger lengths (2D:4D) is thought to be a marker of prenatal androgen exposure. In a sample of over 2,000 participants, men had significantly lower 2D:4D ratios than women (d = .36 and .23 for right and left hands, respectively), and these results were consistent across ethnic groups. Heterosexual men had significantly lower (more male typical) 2D:4D ratios than gay men (d = .32 and .31 for right and left hands, respectively), and these results tended to be consistent across ethnic groups. Heterosexual and lesbian women showed no significant differences in 2D:4D ratios, after ethnicity was taken into account. The current findings add to evidence that prenatal hormonal factors may be linked to men's sexual orientation.
authors.affiliation: Department of Psychology, California State University, Fullerton 92834, USA. rlippa@fullerton.edu
authors.forename: Richard A
authors.initials: RA
authors.lastname: Lippa
mesh_terms: D000328:Adult; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D020010:Heterosexuality; D006716:Homosexuality; D006801:Humans; D008297:Male; D011582:Psychological Theory; D015203:Reproducibility of Results; D012737:Sex Factors; D012725:Sexual Behavior