The Unique and Cumulative Predictive Capacity of Validity Measures to Detect Feigned Psychological, Cognitive, and Medical Conditions: An Analogue Investigation

Contemporary psychological assessments regularly inform high-stakes decisions (e.g., access to treatment, disability status, personnel selection, psychological capacity, work accommodations); the appropriateness of these decisions is not only dependent on accurate test data but also on a clinician’s skill in interpreting response validity. One strength of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) is its array of validity scales designed to detect symptom over-reporting, with certain scales designed to target specific (feigned) symptom clusters (e.g., psychotic, emotional, somatic, cognitive symptoms). Empirical evidence consistently demonstrates that the MMPI-2-RF over-reporting validity scales can systematically differentiate between veridical and non-veridical response styles in both clinical and non-clinical samples. However, recent research suggests that the MMPI-2-RF five over-reporting validity scales, which ostensibly target different sets of feigned symptoms, may lack specificity in differentiating between different types of known-feigning groups. The primary goal of this study was to examine the unique contribution of each of these five MMPI-2-RF over-reporting scales to detect differentially the feigning of psychotic, emotional, cognitive, or somatic disorders/conditions using analogue samples. The secondary goal of this study aimed to explore whether commonly used performance-based validity measures (PVT) offer incremental validity to the MMPI-2-RF over-reporting validity scales in detecting these feigned disorders/conditions. To achieve these goals, 185 undergraduate students participated in a part mixed-model analogue design and were randomly assigned to one of six experimental groups. Participants completed the MMPI-2-RF on two occasions; once with the standard test instructions and then again with different sets of instructions, in which they were coached to feign one of several disorders/conditions; on this occasion the participants also completed a battery of PVTs. Results from this study are broadly consistent with past research indicating that the MMPI-2-RF over-reporting scales can effectively differentiate between veridical and feigned response styles. However, the results from this study offer evidence of incongruence between the conceptual underpinnings and reputed function of some of the over-reporting scales to differentially predict some of the feigned disorders/conditions. Results for the PVTs used in this study highlight the potential benefit of using a multi-method measurement approach in the assessment of non-credible responding.Ph.D