The effects of clinical and scientific expert testimony on juror decision making in capital sentencing.

Abstract

The Supreme Court and many state courts have assumed that jurors are capable of differentiating less accurate clinical opinion expert testimony from expert testimony based on more sound scientific footing and of appropriately weighing these two types of testimony in their decisions. Persuasion and jury decision-making research, however, both suggest that this assumption is dubious. The authors investigated whether mock jurors are more influenced by clinical opinion expert testimony or actuarial expert testimony. Results suggested that jurors are more influenced by clinical opinion expert testimony than by actuarial expert testimony and that this preference for clinical opinion expert testimony remains even after the presentation of adversary procedures. Limited empirical evidence was found for the notion that various types of adversary procedures will have a differential impact on the influence of expert testimony on juror decisions.