The utility of psychopathy measures in predicting violence is largely explained by their assessment of social deviance (e.g., antisocial behavior; disinhibition). A key question is whether social deviance "interacts" with the core interpersonal-affective traits of psychopathy to predict violence. Do core psychopathic traits multiply the (already high) risk of violence among disinhibited individuals with a dense history of misbehavior? This meta-analysis of 32 effect sizes (N = 10,555) tested whether an interaction between the Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 2003) Interpersonal-Affective and Social Deviance scales predicted violence beyond the simple additive effects of each scale. Results indicate that Social Deviance is more uniquely predictive of violence (d = 0.40) than Interpersonal-Affective traits (d = 0.11), and these two scales do not interact (d = 0.00) to increase power in predicting violence. In fact, Social Deviance alone would predict better than the Interpersonal-Affective scale and any interaction in 81% and 96% of studies, respectively. These findings have fundamental practical implications for risk assessment and theoretical implications for some conceptualizations of psychopathy. (Contains 1 figure and 2 tables.)