Examining the Reliability and Validity of an Abbreviated Psychopathic Personality Inventory-Revised (PPI-R) in Four Samples

A recently developed 40-item short-form of the Psychopathic Personality Inventory-Revised (PPI-R; Lilienfeld & Widows, 2005) has shown considerable promise as an alternative to the long-form of the instrument (Eisenbarth, Lilienfeld, & Yarkoni, 2015). Beyond the initial construction of the short-form, however, Eisenbarth et al. only evaluated a small number of external correlates in a German college student sample. In this study, we evaluate the internal consistency of the short-form scales in 4 samples previously administered the full PPI-R (3 U.S. college student samples and 1 U.S. forensic psychiatric inpatient sample) and examine a wide range of external correlates to compare the nomological nets of the short- and long-forms. Across all 4 samples, correlations between each short-form scale and its corresponding long-form scale were uniformly high (all rs > .75). In terms of external correlates, the pattern of associations was exceedingly similar, for the short-form and long-form composites with a largely trivial reduction in effect size. Collectively, our findings offer considerable support for the utility of this new short-form as a substitute for the full PPI-R.