title: Second to fourth digit length ratio (2D:4D) and adult sex hormone levels: new data and a meta-analytic review.
abstract: The relative length of the second (index) to the fourth (ring) finger (2D:4D) is a putative negative correlate of prenatal testosterone (T) exposure. Therefore, 2D:4D (and to a lesser extent D(r-l), the difference between 2D:4D in the right hand and in the left hand) has often been used to study effects of prenatal androgenization on human behavior and cognition. However, evidence suggests that 2D:4D may also be related to levels of circulating sex hormones in adults. This would question the validity of 2D:4D as a means of studying the effects of prenatal sex hormones. Here we present new data from two non-clinical samples (64 women and 102 men) regarding the relationships of 2D:4D and D(r-l) with circulating sex hormone levels. We then present a meta-analytic review of all the present evidence regarding this issue. The results suggest that, in the normal population, 2D:4D and D(r-l) are not associated with adult sex hormone levels. The findings from this current study add to the growing body of evidence demonstrating that 2D:4D is a suitable tool to study the effects of prenatal androgenization on human behavior and cognition.
authors.affiliation: Technische Universität Chemnitz, Institut für Psychologie, Wilhelm-Raabe Str. 43, D-09120 Chemnitz, Germany. johannes.hoenekopp@phil.tu-chemnitz.de
authors.forename: Johannes
authors.initials: J
authors.lastname: Hönekopp
authors.forename: Luise
authors.initials: L
authors.lastname: Bartholdt
authors.forename: Lothar
authors.initials: L
authors.lastname: Beier
authors.forename: Andreas
authors.initials: A
authors.lastname: Liebert
mesh_terms: D000328:Adult; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D012739:Gonadal Steroid Hormones / Q000032:analysis*; D006801:Humans; D008297:Male
chemical_list: D012739:Gonadal Steroid Hormones