There is substantial interest in research on psychopathic personality order within the fields of forensic psychology and mental health law. In large part, the basis of this interest is the well-replicated finding that there is a robust link between psychopathy and violent behavior. In brief, psychopathy is a clinical construct used to describe an interrelated constellation of deficits in affect (e.g., callousness, low empathy), interpersonal relations (e.g., manipulativeness, grandiosity), and behavior (e.g., impulsiveness, risk-taking behavior).

“Although our findings supported the important role that psychopathy can play in risk assessment for general types of misconduct, we found that the relation is not as robust under certain circumstances.”

Hare’s (1991/2003) Psychopathy Checklist–Revised (PCL-R) is the most frequently used measure to assess psychopathy. In this paper, we analyzed all available research on the relation between the PCL-R and violence committed in various types of institutions. Although our findings supported the important role that psychopathy can play in risk assessment for general types of misconduct, we found that the relation is not as robust under certain circumstances.

Specifically, we found that the association was weakest for physical violence—especially in studies conducted in U.S. prisons—which holds significant implications for violence risk assessment in capital murder trials. From an applied risk assessment perspective, our results highlight the importance of using empirically validated risk factors that have been demonstrated to be valid for the context-specific outcome being forecasted.

Although our paper was not the first quantitative synthesis on this topic, we were the first to investigate a hierarchy of increasingly specific types of violent outcomes. We also examined, for the first time, several important variables that might moderate the association between violence and psychopathic personality disorder.

In the present paper, we used a statistical procedure (meta-analysis) to aggregate published and unpublished research findings on the association between PCL-R-defined psychopathy and violence committed in institutional settings (such as hospitals and prisons). The PCL-R is considered to be the most valid and reliable instrument for measuring the construct of psychopathy in correctional and forensic psychiatric populations. We found that, overall, PCL-R scores are related to institutional violence. However, they were weakest for physical violence.

Importantly, we also learned that the context in which an assessment is made appears to be a significant factor in understanding the association between psychopathy and institutional misconduct. In particular, we found that the PCL-R does not function as effectively at identifying high-risk offenders in U.S. institutions—particularly U.S. prisons—as they do in non-U.S. samples.

I became involved in this research while I was a graduate student working with Dr. John Edens (now at Texas A&M University). Among other topics, Dr. Edens has published papers regarding predictions of future dangerousness in capital murder trials in general, as well as the role (and misuses) of the PCL-R in this and other legal decision-making contexts.

I will continue to conduct research on violence risk assessment, including investigations pertaining to the role of specific risk factors for violence (e.g., psychopathy, psychosis) as well as the impact of using different violence risk assessment technologies and decision-making approaches.

The use of the PCL-R within an institutional setting can have a dramatic impact on a person’s life and liberty—test results can affect security level classification within institutions as well as decisions about release and, in the United States, influence whether the death sentence is meted out.

Our results clearly call into question the use of the PCL-R in the context of capital murder trials in the United States, where it would seem that the low magnitude of correlations that we found—e.g., 11 for physical violence and 10 for general aggression for U.S. prison studies—will be even more attenuated given the lower base rate of prison violence among death row and life-sentenced inmates relative to general population offenders.