Sensitivity of MMPI-2 validity scales to underreporting of symptoms.

Standard and supplementary scales designed to detect underreporting of symptoms on the Minnesota Multiphasic Personality Inventory (S. R. Hathaway & J. C. McKinley, 1983) and Minnesota Multiphasic Personality inventory-2 (MMPI-2 ; J. N. Butcher, W. G. Dahlstrom, J. R. Graham, A. Tellegen, & B. Kaemmer, 1989) were investigated in two groups of participants. Fifty individuals who completed the MMPI-2 under a fake-good instruction set were compared to 50 matched individuals who completed it under the standard instructions. Fake-good participants scored significantly higher than standard participants on all underreporting scales. Effect sizes showed that fake-good participants differed from standard participants by nearly 2 SD on the average. Hierarchical regression and discriminant function analyses suggested that two supplementary underreporting scales, J. S. Wiggins's (1959) Social Desirability Scale and the Superlative Scale (J. N. Butcher & K. Han, 1993), have significant incremental validity over the traditional L and K scales in discriminating standard from underreported profiles.