Qualitative and quantitative characteristics of malingered and other invalid WAIS-R and clinical memory data.

To further the understanding of malingering and other compromises to data validity on standard neuropsychological tasks, the present study evaluated WAIS-R and clinical memory data produced by two groups from a mildly head-injured sample: Malingerers (MPs; n = 12) were identified via below chance forced-choice testing; "QVs" (n = 10) provided implausible neuropsychological performances but were not clearly malingering. A low level of performance characterized the data of the MPs and QVs: Full Scale IQ and Performance IQ were significantly lower for MPs and QVs than for matched controls, and obtained IQ for MPs and QVs averaged 18 points below estimated IQ. On the California Verbal Learning Test, total words recalled and recognition memory were significantly lower for MPs and QVs than for controls. In contrast, qualitative analyses, such as approximate answers, bizarre responses, "scatter" on the WAIS-R, inconsistency in performance across similar tasks, clustering, and intrusions on memory measures, generally yielded negative findings.