Examination of the new MMPI-2 Response Bias Scale (Gervais): relationship with MMPI-2 validity scales

Validity scales were recently developed to improve assessment of symptom validity beyond original MMPI-2 validity scales. In an initial study, the Response Bias Scale (RBS; Gervais, 2005) was developed based upon non-head-injury claimant performances on a cognitive effort measure, the Word Memory Test (WMT). The present study examined relationships of the RBS with numerous MMPI-2 validity scales in a sample of 211 participants with secondary gain (SG) or no secondary gain (NSG). Of the validity scales observed, RBS yielded the largest effect size difference between groups (d = .65), followed closely by FBS (d = .60) and the L-scale (d = .51). Overall, RBS correlated most significantly (r = .74, p < .001) with FBS, but also showed significant correlations with most other validity scales for both groups. RBS further demonstrated significant correlations (p < .001) with all clinical scales except for Mf. Findings suggest that RBS and FBS may represent a similar construct of symptom validity, and may outperform other MMPI-2 validity scales in discriminating SG and NSG groups. Findings provide preliminary support for use of RBS within the forensic context.