The Impact of Coaching on Feigned Psychiatric and Medical Symptoms: A Meta-Analysis Using the MMPI-2

Coaching individuals on test-taking strategies presents legal and ethical concerns and threatens the validity of psychological test score interpretations, which could lead to inaccuracies in clinical settings and injustices within the legal system. This meta-analysis examined the impact of coaching on the detection of symptom exaggeration or feigning on the MMPI-2. A total of 99 feigning studies (N = 19,536) comparing validity subscale scores between genuine and nongenuine (coached or non-coached) responders were analyzed. Potential moderating effects of control group, type of symptoms, publication status, financial incentive, and non-content validity screening were also examined regarding their impact on the effectiveness of coaching. Findings suggested that detection-based coaching (i.e., coaching regarding the presence of validity scales and detection avoidance strategies within the MMPI-2) improved individuals' ability to elude detection by the MMPI-2 validity scales. Nonetheless, the MMPI-2 validity scales still generated moderate to very large effect sizes in detecting symptom exaggeration or feigning even in the context of coaching (range g =.89 to 1.95). The findings provide reassurance for detection efforts, indicating that while the effectiveness of the MMPI-2 is somewhat diminished, it remains useful in detecting non-genuine responders even in the context of coaching.