DETECTION OF UNDERREPORTING OF PSYCHOPATHOLOGY ON THE MMPI - A METAANALYSIS

We reviewed the empirical literature on detection of underreporting of psychopathology on the MMPI. Meta-analytic techniques were applied to 25 studies in which subjects responding honestly were compared to subjects underreporting psychopathology. Several indices of underreporting were examined, including the L and K scales, F - K, L + K, social desirability scales, subtle/obvious scales, and the Positive Malingering scale. An overall mean effect size of 1.05 was obtained, suggesting that subjects underreporting psychopathology differ from subjects responding honestly by approximately 1 standard deviation, on the average, on these scales. The Positive Malingering scale and one of the social desirability scales showed promising effect sizes of approximately 1. 5 standard deviations. For the L and K scales, effect sizes of just under 1 standard deviation were noted. Cutting scores for detection of underreporting on these scales also were examined. A wide variety of cutting scores were employed in different studies, suggesting that consistently effective criteria have yet to be established. Applications of these findings to the recently published MMPI-2 are discussed.