CAT-PD and MMPI-3 Validity Scales Detect Simulated Overreporting and Underreporting

Individuals can sway legal, medical, employment, or other decisions by dishonestly self-reporting on psychological tests. Accordingly, the Comprehensive Assessment of Traits relevant to Personality Disorder (CAT-PD) and the Minnesota Multiphasic Personality Inventory-3 (MMPI-3) include validity scales to detect overreporting and underreporting. Although many studies have empirically tested the validity scales of the MMPI-2 and the MMPI-2-RF, fewer have done so with the updated MMPI-3, and none with the CAT-PD. Therefore, in the present study, a simulation design was conducted to determine how successfully the CAT-PD and MMPI-3 validity scales would discriminate between credible responders and noncredible responders (i.e., overreporters and underreporters). Undergraduates and crowd-sourced adults (Total N = 484) were randomly assigned to respond honestly, overreport, or underreport while completing the MMPI-3 and the CAT-PD. Relative to honest responders, overreporters and underreporters significantly increased their respective validity scale scores (Cohen's d range = 1.04 - d = 4.87); they also significantly biased their substantive scale profiles. Moreover, CAT-PD validity scales demonstrated convergent and discriminant validity with MMPI-3 validity scales and similar classification accuracy estimates via receiver operating characteristic curves. These results suggest that, within a nonclinical simulation design, CAT-PD and MMPI-3 validity scales both effectively detect noncredible responding.