Prenatal testosterone and personality: Increasing the specificity of trait assessment to detect consistent associations with digit ratio (2D:4D)

Prenatal testosterone exposure has been suggested to influence various personality traits including assertiveness/social dominance, aggressiveness, and impulsive sensation seeking (ImpSS). However, correlational work using 2D:4D digit ratio as an indicator for prenatal testosterone only converged on extremely small effects. Here we show that measuring traits with a high degree of specificity by combining extensive personality assessment, factor analysis with oblique rotation and subsequent partialling reveals an association between ImpSS and low 2D:4D (i.e. presumably high prenatal testosterone) in young healthy males. These findings suggest that prenatal testosterone exposure predicts ImpSS in men, that 2D:4D-personality associations are more specific than generally appreciated and that such associations can be more reliably detected using the approach to trait assessment described here.

► Factor analysis of 53 personality scales results in six correlated factors.
► Only the impulsive sensation seeking factor is associated with digit ratio (2D:4D).
► The association only survives appropriate correction for multiple testing after partialling the other factors.
► The link between personality and 2D:4D is highly specific.