Noncredible performance in individuals with external incentives: empirical derivation and cross-validation of the Psychosocial Distress Scale (PDS).

Using a known groups design, a new Minnesota Multiphasic Personality Inventory (MMPI-2) subscale, the 20-item Psychosocial Distress Scale (PDS), was empirically derived and cross-validated. The PDS demonstrated good classification accuracy between subjects under external incentive vs. no incentive conditions. In the initial calibration sample (N = 84) a cut score of ≥10 on the PDS was associated with good classification accuracy (85.7%), high specificity (90.0%), and adequate sensitivity (81.8%). Under cross-validation conditions (N = 83) a cut score of ≥10 on the PDS was also associated with nearly identical classification accuracy (86.5%), specificity (91.89%), and sensitivity (82.61%). A cut score of ≥12 was associated with 100% positive predictive power; that is, no false-positive errors in both the initial calibration sample and the subsequent cross-validation sample. The current study suggests that in addition to noncredible cognitive performance, civil litigants and disability claimants may overreport psychosocial complaints that can be identified and that the scale may generalize to other settings and patient groups.

Higher order factor structure of the WISC-IV in a clinical neuropsychological sample.

A confirmatory factor analysis was conducted examining the higher order factor structure of the WISC-IV scores for 344 children who participated in neuropsychological evaluations at a large children's hospital. The WISC-IV factor structure mirrored that of the standardization sample. The second order general intelligence factor (g) accounted for the largest proportion of variance in the first-order latent factors and in the individual subtests, especially for the working memory index. The first-order processing speed factor exhibited the most unique variance beyond the influence of g. The results suggest that clinicians should not ignore the contribution of g when interpreting the first-order factors.