A psychometric study of stereotypes: assessment of malingering in a criminal forensic group.

This research investigates the validity of the stereotype of insanity defendants as malingerers by analyzing the proportions of insanity defendants who exaggerate psychopathology at the pre- and postacquittal stages of the legal process and by assessing the severity of psychopathology among preacquittal defendants. We administered the Minnesota Multiphasic Personality Inventory (MMPI) to 49 insanity defendants evaluated for fitness to stand trial and/or sanity at the time of the alleged crime and to 52 subjects previously found not guilty by reason of insanity. Results indicated: (a) Contrary to the stereotype, a minority (14% to 41%) of insanity defendants clearly malingered, whereas 22% to 39% showed evidence of minimizing psychopathology. (b) Eighty-one percent of these subjects had MMPI profiles suggestive of psychosis, but relatively few showed evidence of primarily antisocial behavior. Thus, the malingering stereotype may be application to only a minority of insanity defendants and is specifically inapplicable to a substantial proportion who minimized psychopathology or showed evidence of psychosis consistent with the claim of insanity.