Utility of the MMPI-3 validity scales for detecting overreporting and underreporting and their effects on substantive...

The current study utilized an experimental design to investigate the utility of the Minnesota Multiphasic Personality Inventory (MMPI)-3 Validity Scales for detecting overreporting and underreporting and the impact of these response sets on substantive scale scores. College students completed a battery of criterion measures before assignment to a Standard Instructions (SIs) Group (n = 288), an Overreporting Group (n = 250), or an Underreporting Group (n = 215). t tests demonstrated that scores on MMPI-3 overreporting indicators and most substantive scales were higher among the Overreporting Group relative to the SI group with very large effect sizes, and scores on MMPI-3 underreporting indicators were higher and most substantive scales scores were lower among the Underreporting Group relative to the SI group, with moderate to large effects. Classification accuracy estimates documented the effectiveness of MMPI-3 Validity Scales in detecting overreporting and underreporting. Bivariate correlations between MMPI-3 substantive scale scores and criterion measures (which were completed under SIs for all three groups) were substantially attenuated for both simulation groups relative to the SI Group. Bivariate correlations were also attenuated for groups identified as overreporting or underreporting using MMPI-3 Validity Scale scores relative to individuals with valid MMPI-3 protocols, highlighting the need for and importance of appraising threats to protocol validity when assessing personality and psychopathology by self-report. (PsycInfo Database Record (c) 2021 APA, all rights reserved).