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

Area of Science:

• Psychological assessment
• Psychometrics
• Forensic psychology

Background:

• Psychological tests are susceptible to response bias, influencing critical decisions.
• Validity scales are crucial for detecting dissimulation in assessments like the MMPI-3 and CAT-PD.
• Limited research exists on the validity scales of the MMPI-3 and CAT-PD compared to earlier versions.

Purpose of the Study:

• To evaluate the efficacy of CAT-PD and MMPI-3 validity scales in distinguishing credible from noncredible responders.
• To assess the ability of these scales to detect overreporting and underreporting in a simulated nonclinical environment.

Main Methods:

• A simulation design involving 484 participants (undergraduates and crowd-sourced adults).
• Participants were randomly assigned to respond honestly, overreport, or underreport on the MMPI-3 and CAT-PD.
• Receiver operating characteristic (ROC) curves were used to estimate classification accuracy.

Main Results:

• Overreporters and underreporters showed significantly higher validity scale scores compared to honest responders (Cohen's d range = 1.04–4.87).
• Noncredible responding significantly biased substantive scale profiles on both instruments.
• CAT-PD validity scales exhibited convergent and discriminant validity with MMPI-3 validity scales, with similar ROC accuracy.

Conclusions:

• The CAT-PD and MMPI-3 validity scales are effective in detecting noncredible responding in a simulated nonclinical setting.
• These findings support the utility of both instruments' validity scales for ensuring response integrity in psychological evaluations.