The effect of a warning regarding detection of stimulated cognitive and motor deficits on the Wechsler Memory Scale-Revised (WMS-R; Wechsler; 1987) and Grooved Pegboard (Klove, 1963; Matthews di Klove, 1964) was examined. Undergraduates (N = 87) were randomly assigned to one of three conditions: simulators without warning, simulators with warning, and controls. it was predicted that warning participants that simulation efforts will be detected would reduce malingering behavior and this hypothesis was generally supported. Analyses indicated simulators with warning frequently approximated control group performances and were significantly better than simulators without warning on same measures. Stepwise discrimination function analysis accurately classified 57% of all participants. Results provide support for effectiveness of warning in reducing malingering behavior on selected measures and are discussed in terms of the use of wanting as an adjunct to existing procedures, role of the neuropsychologist, and informed consent for assessment in personal injury litigation. (C) 1997 National Academy of Neuropsychology.