Trait Anxiety Moderates the Relationship Between Testosterone Responses to Competition and Aggressive Behavior

Testosterone (T) concentrations change rapidly in the context of human competition, and these changes in neuroendocrine function may serve to modulate future aggressive behavior. However, an increase in T during competition does not translate into aggressive behavior among all individuals. Here, we examined the extent to which individual differences in trait anxiety moderate the relationship between T responses to competition and aggressive behavior. Across two studies, we found that T responses to competition were positively correlated with subsequent aggression, but only among men scoring relatively low in trait anxiety. Trait anxiety did not moderate the relationship between T reactivity and aggression in women. These findings highlight the importance of considering individual difference in trait anxiety when examining the neuroendocrine correlates of human aggression.