The Predictive Capacity of the MMPI-2 and PAI Validity Scales and Indexes to Detect Coached and Uncoached Feigning

Abstract

The objective of this study was to examine the relative effectiveness of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the Personality Assessment Inventory (PAI) validity scales and indexes to detect malingering. Research participants were either informed (coached) or not informed (uncoached) about the presence and operating characteristics of the validity scales and instructed to fake bad on both the MMPI-2 and PAI. The validity scale and index scores produced by these research participants were then compared to those scores from a bona fide sample of psychiatric patients (n = 75). Coaching had no effect on the ability of the research participants to feign more successfully than those participants who received no coaching. For the MMPI-2, the Psychopathology F scale, or F(p), proved to be the best at distinguishing psychiatric patients from research participants instructed to malinger, although the other F scales (i.e., F and Fb) were also effective. For the PAI, the Rogers Discriminant Function index (RDF) was clearly superior to the other PAI fake-bad validity indicators; neither the Negative Impression Management scale nor Malingering Index were effective at detecting malingered profiles in this study. Overall, RDF proved to be marginally superior to F and F(p) in distinguishing MMPI-2 and PAI protocols produced by research participants asked to malinger and psychiatric patients. Both the RDF and the F and F(p) scales, however, were able to increase the predictive capability of one another.