Cluster analysis of a forensic population with antisocial personality disorder regarding PCL-R scores: differentiation of two patterns of criminal profiles.

Fifty six cases of a forensic population were submitted to a cluster analysis to observe the aglomerative behavior in relation to the total scores of the items comprising the PCL-R Psychopathy Checklist Revised [R.D. Hare, Manual for the Hare Psychopathy Checklist-Revised, Multi-Health System, Toronto, 1991]. The analysis indicated two independent types of antisocial personality disorders, not identified in the PCL-R in its standardized form, one of them being strongly associated with criminal conduct and the other with psychopathic personality. Such clusters were stable when the analysis was replicated with other hierarchical algorithms, and also, they were independently extracted via the k-means method without having previously fixed the value for k. One of the clusters concentrated the PCL-R highest scores, indicating that it is the prototypical psychopathic character determinant.