Hypothetical constructs, hypothetical questions, and the expert witness

Professor John Henry Wigmore in 1940 described the hypothetical question as an intolerable obstruction of truth. Since that time, the nature and application of the hypothetical question in the courtroom, as well as responses to this line of questioning during expert testimony, have been sources of controversy. Governed by legal philosophical foundations, the hypothetical construct addresses what there is, in a general sense, and what can or ought to be. Alexy (2004) has described the nature of legal philosophy as the epistemological question of what we can know. This article begins by examining the philosophical underpinnings, legal parameters, and teaching purposes of posing hypothetical queries. A social–psychological backdrop for the use of hypothetical questions is then discussed followed by a broader discussion of the hypothetical question's role in court procedures. This paper identifies hypothetical questions used in court as devices to elicit information, or as predictions that potentially change underlying factual interpretations of evidence. In particular, on cross examination hypothetical questions seek to make opposing experts assume facts that are incongruent with their conclusions or opinions. Sometimes in these situations, experts are led to re-evaluate opinions based on alternative understandings of events and behaviors. Thus, this paper's final aim is to explore a foundational understanding of hypothetical questions asked of expert witnesses with special reference to mental health issues. Options for responding to hypothetical questions on the stand are considered along the dimensions of assertiveness–passivity, compliance–resistance, and possible redefinitions of the hypothetical issues.