Psychopathic predators? Getting specific about the relation between psychopathy and violence.

Objective: The psychopathy checklist-revised (PCL-R; Hare, 1991, 2003) is often used to assess risk of violence, perhaps based on the assumption that it captures emotionally detached individuals who are driven to prey upon others. This study is designed to assess the relation between (a) core interpersonal and affective traits of psychopathy and impulsive antisociality on the one hand and (b) the risk of future violence and patterns of motivation for past violence on the other.

Method: A research team reliably assessed a sample of 158 male offenders for psychopathy, using both the interview-based PCL-R and the self-report psychopathic personality inventory (PPI: Lilienfeld & Andrews, 1996). Then, a second independent research team assessed offenders' lifetime patterns of violence and their motivation. After these baseline assessments, offenders were followed in prison or the community for up to 1 year to assess their involvement in 3 different forms of violence. Baseline and follow-up assessments included both interviews and reviews of official records.

Results: First, the PPI manifested incremental validity in predicting future violence over the PCL-R (but not vice versa)-and most of its predictive power derived solely from impulsive antisociality. Second, impulsive antisociality-not interpersonal and affective traits specific to psychopathy-were uniquely associated with instrumental lifetime patterns of past violence. The latter psychopathic traits are narrowly associated with deficits in motivation for violence (e.g., lack of fear or lack of provocation).

Conclusions: These findings and their consistency with some past research led us to advise against making broad generalizations about the relation between psychopathy and violence.