A taxometric analysis of the Psychopathy Checklist: Screening Version (PCL:SV): further evidence of dimensionality.

A taxometric analysis of the Psychopathy Checklist: Screening Version (PCL:SV; S. D. Hart, D. N. Cox, & R. D. Hare, 1995) was performed on a group of 2,250 male and female forensic/psychiatric patients and jail/prison inmates. The 4 PCL:SV facet scores (Interpersonal, Affective, Impulsive Lifestyle, Antisocial Behavior) served as indicators in this study, and the data were analyzed with 3 principal taxometric procedures--mean above minus below a cut, maximum eigenvalue, and latent mode factor analysis. The results show evidence of dimensional structure on the PCL:SV in the full sample as well as in all 8 subsamples (men, women, Whites, Blacks, hospital patients, jail/prison inmates, file review with an interview, file review without an interview). These findings corroborate recent taxometric research on the Psychopathy Checklist-Revised (R. D. Hare, 1991, 2003) in which results have been largely dimensional in nature. It is concluded that scores on the PCL:SV differ quantitatively as points on a dimension (high vs. low psychopathy) rather than partitioning into qualitatively distinct categories of behavior (psychopath vs. nonpsychopath).