title: 2d:4d, sex steroid hormones and human psychological sex differences.
abstract: Studies on 2d:4d, the ratio between the second and the fourth digit, as a possible indicator of prenatal androgen exposure, have failed to produce consistent results. This paper analyzes the relation between 2d:4d, sex steroids and well-documented sex differences in characteristics such as depression, dominance, and aggressive (ART) and non-aggressive adolescent risk-taking (NART) in a comparatively large sample of adolescent boys (N=301, mean age: 14.4 years) and girls (N=298, mean age: 14.3 years). Boys had on average a lower 2d:4d than girls (F=42.15; p<0.001). With respect to boys, controlling for age and pubertal development (PD), a small but marginally significant positive association was found between 2d:4d and total testosterone (TT) (r=0.11; p<0.05). In girls a significant association was found between 2d:4d and SHBG (r=0.18; p<0.01). However, relationships between 2d:4d and hormones depended on the phase of the menstrual cycle, with 2d:4d being negatively associated with FT (B=-0.013; p<0.05) once a positive association between 2d:4d and FT for girls in the mid-cycle group (B=0.019; p<0.01) is taken into account. With respect to sex differences in characteristics, we found evidence of a relationship between 2d:4d and depression in boys (r=-0.14; p<0.05) but not between 2d:4d and dominance, ART or NART. No relationships were found between 2d:4d and any of these variables in girls.
authors.affiliation: Department of Sociology, University of Ghent, Korte Meer 5, Ghent 9000, Belgium. hans.vermeersch@ugent.be
authors.forename: Hans
authors.initials: H
authors.lastname: Vermeersch
authors.forename: Guy
authors.initials: G
authors.lastname: T'Sjoen
authors.forename: J M
authors.initials: JM
authors.lastname: Kaufman
authors.forename: J
authors.initials: J
authors.lastname: Vincke
mesh_terms: D000293:Adolescent; D003863:Depression / Q000503:physiopathology; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D005783:Gender Identity; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000097:blood; D012727:Sex Characteristics; D012930:Social Dominance
chemical_list: D012739:Gonadal Steroid Hormones