Performance-verbal discrepancies and facets of psychopathy: assessing the relationship between WAIS–R/III summary IQs/index scores and PCL–R facet scores

The purpose of this paper is to explore the relationship between differences in performance and verbal intelligence quotients (PIQ and VIQ) and the four facet scores from the Psychopathy Checklist–Revised (PCL–R) (Hare, 2003).

Wechsler Adult Intelligence Scale (WAIS) and PCL–R facet scores provided by 181 male federal inmates as part of a forensic evaluation were analyzed with multiple regression, paired t-tests, and receiver operating characteristic (ROC) curves.

Of the four PCL–R facet scores, only elevations on Facet 4 (antisocial) produced a significant WAIS-Revised (Wechsler, 1981) PIQ over VIQ (PIQ>VIQ) effect. In addition, only Facet 4 achieved significant ROC accuracy and correlated with the PIQ>VIQ discrepancy after other potentially important variables were controlled. In a follow-up study of 46 male inmates, Facet 4 correlated negatively with the Verbal Comprehension and Working Memory indices of the WAIS–Third Edition (Wechsler, 1997) and accurately classified a significant portion of Perceptual Organization Index (POI)>WMI cases but not a significant portion of POI>VCI cases.

Verbal comprehension and executive function deficits are examined as possible explanations for the relationships observed in this study.

These results have potentially important implications for forensic assessment in that they suggest that only certain specific features of the psychopathy construct are related to the well-known PIQ>VIQ discrepancy.