The Elements of Persuasion in Expert Testimony

Abstract

Much has been written about mental health expert testimony, particularly regarding the scientific bases of testimony and the ethical questions which arise in the context of giving testimony. While the mental health expert may be perceived as helping the courts find the “truth” in the adversary process, the expert witness's impact may depend more on elements of persuasion than on the truthfulness of his or her formulations regarding the particular case. This article focuses on the elements of persuasion in mental health expert testimony, drawing on the social sciences literature, legal wisdom, and the authors' anecdotal experiences as forensic psychologists. Suggestions for increasing persuasiveness in testimony are given.