Digit ratio (2D:4D) is associated with traffic violations for male frequent car drivers

Digit ratio (2D:4D) is a putative marker of prenatal hormone exposure. A lower digit ratio has been suggested as an index of higher testosterone relative to estrogen exposure during prenatal development. Digit ratio has been associated with a variety of psychological sex-dimorphic variables, including spatial orientation, aggression, or risk-taking behavior. The present study aimed to relate digit ratio to traffic violations for a male sample (N = 77) of frequent car drivers. Digit ratio was assessed via printout scans of the hand, and traffic offense behavior was assessed via self-reported penalty points as registered by the Central Register of Traffic Offenders in Germany. In addition, social desirability and sensation seeking were recorded. Results showed that digit ratio was inversely related to penalty point entries, suggesting more traffic violations for individuals with higher prenatal testosterone exposure. Sensation seeking was positively associated with traffic violations, but there was no relationship between sensation seeking and digit ratio, proposing additive effects of both variables. The results suggest that prenatal androgen exposure might be related to traffic violations for frequent car drivers.