A multidimensional scaling analysis of the Hare PCL-R: Unfolding the structure of psychopathy

Recent studies examining the Psychopathy Checklist – Revised (PCL-R) have argued for a range of factorial solutions to describe and explain the dimensions of psychopathy. This study details an empirical analysis of North American PCL-R data for 4630 male offenders, using multidimensional scaling (MDS) as a non-linear alternative to factor analysis. The emergent structure of Hare's psychopathy psychometric can be interpreted in more than one way and at different levels of specificity. The multidimensional scalograms reveal a set of facets consistent with the two- and four-factor solutions that emerge from the same data. Equally the structure of the PCL-R can be interpreted through personality theory as a set of core traits and behavioural manifestations, consistent with an evolutionary basis for psychopathic tendencies. These analyses provide support for a multidimensional structure within the PCL-R, and suggest that psychopathy can be viewed as an extreme variant of multiple dimensions of personality.