Personal values and the value of expert testimony

Abstract

Psychologists who routinely offer expert testimony to the courts about the problems of eyewitness testimony demonstrate an unwarranted degree of faith in experimental psychology. Although progress in the field ultimately depends on laboratory research, the extrapolation of laboratory research to the real world is fraught with difficulties. Among the difficulties are the following: Laboratory studies are typically not designed with ecological validity in mind, they involve “fixed effects” statistical designs, they do not tell us how individuals (as opposed to mean values) behave under various experimental conditions. Presentation of such studies as relevant to the specific conditions of a court case entails a significant misrepresentation of the results of the research.