Identifying subtypes of criminal psychopaths: A replication and extension.

Psychopathy is an important construct in offender classification. Although several studies have suggested that there are two distinct subtypes of psychopaths, these studies have considerable limitations, including reliance on self-report measures, a failure to adequately address heterogeneity within the construct of psychopathy, and predictor-criterion contamination. A recent taxonomic study identified four subgroups of offenders, including primary and secondary psychopaths. We used cluster analysis to replicate and extend those findings to: 1) an independent sample; and 2) a PCL-R factor model that reduces predictor-criterion contamination. Additionally, we validated initial results using a novel clustering method. Results show that psychopathy subtypes are replicable across methods. Moreover, comparisons on other variables provide external validation of the subtypes consistent with prior theoretical conceptualizations.