Second-to-fourth digit ratio (2D:4D) is unrelated to measures of somatic reproductive effort among young men from Cebu, the Philippines

Abstract Objectives A low second-to-fourth (2D:4D) digit ratio, a retrospective marker of high prenatal androgens, predicts increased investment in costly sexually dimorphic traits in men in some studies, although results are mixed. Here we test the hypothesis that the association of low 2D:4D ratios with increased muscularity and decreased adiposity depends on current testosterone (T) levels, such that digit ratio will be a particularly strong predictor of outcomes among men exhibiting a mating-effort-oriented endocrinological profile (high T). We also test the association between 2D:4D and somatic traits independently of T. Materials and methods We related 2D:4D digit ratios, and their interaction with T, to handgrip strength, lean mass, arm muscle area, and skinfold thickness in a sample of young, childess men (20?22 y) from Cebu, Philippines (N?=?623). Results Digit ratio did not significantly predict men's T-dependent somatic traits. Interactions between 2D:4D and morning T, similarly, did not predict male muscularity or adiposity. Although two of the interactions were significant or marginally significant (p?