The association between the 2D:4D ratio and psychopathic characteristics.

Prior research has identified relations between prenatal testosterone exposure and various antisocial and criminal behaviors. However, less is known about the association between prenatal testosterone exposure and personality traits, such as psychopathy. This study used self-report and biometric data from a sample of undergraduates ( = 491) at a large southwestern university to examine the association between prenatal testosterone exposure (measured by the 2D:4D ratio) and three dimensions of psychopathy (i.e., callousness, egocentricity, and antisocial behavior). Analyses were stratified by sex to explore sex-specific biological underpinnings of psychopathy in young adulthood. Results showed that males scored significantly higher in psychopathic traits and reported significantly lower 2D:4D ratios, compared to females. Additionally, 2D:4D ratios were negatively associated with egocentricity in males, but not females. These findings contribute to a growing literature on the organizational effects that prenatal testosterone exposure may have on the development of different dimensions of psychopathy.