A Comparison of Performance Validity Measures in Predicting MMPI-2 Lie Scale Results

Abstract Objective: This study examined the relationship between tests of performance validity (PVT) and symptom validity (SVT) among claimants undergoing independent neuropsychological evaluations. Previous research comparing PVTs with SVTs has examined symptom validity with respect to overreporting impairment, whereas the current study focused on how PVTs predict underreporting of psychological symptoms and minimization of negative personality characteristics. Method: The sample included 99 claimants presenting with psychological and cognitive complaints who were assessed in a private practice setting. Participants were administered several SVTs (MMPI-2 Lie Scale (L), Superlative Self Presentation Scale (S), Correction Scale (K)) and PVTs, including Reliable Digit Span (RDS), California Verbal Learning Test forced choice recognition, the Victoria Symptom Validity Test (VSVT), and the Test of Memory Malingering (TOMM). Results: Analyses revealed moderate yet significant (p<.001) negative correlations between the L Scale and PVTs with exception of the VSVT. These relationships were substantiated by moderate to large effect sizes (d = 0.56–0.81) when comparing L Scale scores in above and below PVT cutoff conditions. Significant relationships between PVTs and the K and S Scales were not observed. Exploratory analyses revealed that PVT/L Scale relationships were not significantly moderated by presenting concern. Conclusions: Claimants exhibiting invalid PVT performance were more likely to endorse virtuous personality characteristics on the L Scale, supporting the idea that PVT and SVT constructs are interrelated, particularly in the domain of underreporting moral flaws.