Examining the Necessity for and Utility of the Psychopathic Personality Inventory-Revised (PPI- R) Validity Scales

The present study aimed to investigate the need for and utility of the Psychopathic Personality Inventory-Revised (PPI-R) Deviant Responding (DR) and Virtuous Responding (VR) validity scales in identifying overreporting and underreporting, respectively. Since the PPI-R was published, there has not been an independent peer-reviewed examination of these scales. Participants were 384 undergraduate individuals asked to respond to the PPI-R under standard, underreporting, or overreporting instructions. A comparison group consisting of 200 forensic psychiatric patients was also used for the overreporting analyses. Effects of response bias on mean elevations on the PPI-R substantive scales were examined along with the effects on the PPI-R total, factor, and content scales' correlations with other relevant extratest measures of psychopathy. Mean elevations differed significantly, and correlations with extratest measures of psychopathy were significantly lower. Substantial decrement in psychometric validity of PPI-R scores was observed in the simulation conditions. In addition, the utility of the PPI-R validity scales in differentiating between groups was also determined. Both the VR and DR scales showed utility in differentiating between their respective dissimulation condition and the comparison groups, with acceptable rates of sensitivity and specificity.