THE PSYCHOLOGIST AND PSYCHIATRIST IN COURT: PERCEIVED EXPERTNESS AND INFLUENCE.

Abstract

An analog study was devised to examine perceived differences between psychiatrists and psychologists in providing expert testimony on the insanity defense. The effects of issue involvement and initial attitude were also assessed. Subjects who had been exposed to the differences in training between the professionals were used. In a pilot investigation, subjects were exposed to identical testimony from a defense expert identified either as a psychiatrist or psychologist. Medical bias, as measured by the tendency to concur with the expert recommendations and endorse attitudes consistent with the M.D., was confirmed. This finding was especially strong among pro insanity defense subjects with low issue involvement. The failure to find a similar pattern among anti-insanity defense subjects with low issue involvement was thought to be an artifact of the absence of opposing testimony. The overall failure of highly involved anti insanity defense subjects to reach verdicts consistent with their initial attitudes, was also thought to result from the lack of opposing testimony. The primary study was designed to clarify the findings of the pilot investigation and to approximate a more authentic court situation by including an opposing expert. Witness credentials were manipulated while testimony remained constant. Some subjects were exposed to the Ph.D. for the defense and M.D. for prosecution and others to the M.D. for the defense and Ph.D. for the prosecution. Medical bias was evident in this study, again measured by the tendency to follow the recommendations of the M.D. and endorse attitudes consistent with those recommendations. Additionally, subjects tended to evaluate the psychiatrist more favorably than the psychologist. Subjects with low issue involvement were more susceptible to the influence of the medical expert. Highly issue involved subjects maintained their initial attitudes. Attitudes, issue involvement and credentials seemed to affect memory for facts of the case. In some instances, initial attitudes became stronger when mock jurors were exposed to the opposing view (polarization). Implications and limits of these findings were explored.