An Investigation of the Validity of the MMPI-2 Response Bias Scale Using an Analog Simulation Design

Abstract

This study evaluated a measure of feigned cognitive symptoms, the MMPI-2 Response Bias Scale (RBS), using an analog simulation design. A total of 81 participants were randomly allocated to one of two conditions: simulation (n = 40) or control (n = 41). Simulators were instructed to feign memory impairment. All participants completed an abbreviated form of the MMPI-2, Warrington's Word Recognition Memory test, and the Test of Memory Malingering. MMPI-2 data were used to calculate the RBS, F, K. FBS scores were prorated. Significant group differences were found on all measures. The effect size of group differences was largest for the RBS (d = 2.52) compared to the prorated FBS (d = 2.11), F (d = 1.31), and K (d = 0.85). Despite strong significant correlations between MMPI-2 scores, the RBS added incrementally to the other validity indicators in the prediction of group membership. The results from this RBS simulation study are consistent with several previous known-groups evaluations, which suggest that this scale is a useful indicator of negative response bias associated with exaggerated memory impairment.

Keywords:

• Neuropsychological assessment
• Response Bias Scale
• Minnesota Multiphasic Personality Inventory-2
• MMPI-2
• Negative response bias
• Feigned cognitive impairment

Notes

¹For more information about the development of the RBS readers are referred to a recent paper by Wygant and colleagues that includes a detailed summary of early RBS scale development studies (Wygant et al., 2010).

²The eigenvalues and percentage of variance of the regression coefficient for each of the predictors was as follow: F = 1% (eigenvalue 1), 9% (eigenvalue 2), 54% (eigenvalue 3), 23% (eigenvalue 4), 13% (eigenvalue 5); the prorated FBS = 0% (eigenvalue 1), 0% (eigenvalue 2), 17% (eigenvalue 3), 17% (eigenvalue 4) and 65% (eigenvalue 5); K = 0% (eigenvalue 1), 7% (eigenvalue 2), 2% (eigenvalue 3), 62% (eigenvalue 4), 28% (eigenvalue 5); and RBS = 0% (eigenvalue 1), 1% (eigenvalue 2), 3% (eigenvalue 3), 7% (eigenvalue 4) and 89% (eigenvalue 5).

³VIF and tolerance statistics (tol) were as follows: F VIF = 2.87, F tol = .35; prorated FBS VIF = 4.11, prorated FBS tol = .244; RBS VIF = 7.11, RBS tol = .14; K VIF = 1.52, K tol = .656.