Development and initial validation of the Scale of Scales (SOS) overreporting scores for the MMPI family of instruments.

Overreporting is a common problem that complicates psychological evaluations. A challenge facing the effective detection of overreporting is that many of the identified strategies (e.g., symptom severity approaches; see Rogers & Bender, 2020) are not incorporated into broadband measures of personality and psychopathology (e.g., Minnesota Multiphasic Personality Inventory family of instruments). While recent efforts have worked to incorporate some of these newer strategies, no such work has been conducted on the MMPI-3. For instance, recent symptom severity approaches have been used to identify patterns of multivariate base rate "skyline" elevations on the BASC, and similar strategies have been adopted into the PAI to measure psychopathology (Multi-Feigning Index; Gaines et al., 2013) and cognitive symptoms (Cognitive Bias Scale of Scales; Boress et al., 2022b). This study used data from a simulation study (n = 318) and an Active-Duty (AD) clinical sample (n = 290) to develop and cross-validate such a scale on the MMPI-2-RF and MMPI-3. Results suggest that the MMPI SOS (Scale of Scales) scores perform equitably to existing measures of overreporting on the MMPI-2-RF and MMPI-3 and incrementally predict a PVT-classified "known-group" of Active Duty service members. Effects were generally large in magnitude. Classification accuracy achieved desired specificity (.90) and approximated expected sensitivity (.30). Implications of these findings are discussed, which emphasize how alternative overreporting detection strategies may be useful to consider for the MMPI. These alternative strategies have room for expansion and refinement.