Behavioral Correlates of Statement Credibility: Theories, Paradigms, and Results

Abstract

A central goal of each trial process is the reconstruction of past events. The available information, whether it be factual evidence or verbal statements of the accused or of eyewitnesses, has to be evaluated in the light of this basic task. In the case of factual evidence, the evaluation task is basically a question of interpretation of facts while the facts themselves are only seldom in question. Things are quite different, however, if the evaluation has to be based on witness statements. Witness statements cannot be taken at face value. There are, in fact, numerous factors which might lead to discrepancies between the actual course of past events and details of a statement. The degree of congruence between a statement and the original stimuli will be referred to as the reliability of that statement. The various reasons for unreliable witness accounts can be classified into two basically different groups of factors: First, witnesses, although trying to give a correct and complete report of an event or a precise description of a person, may be subject to unconscious and unintended errors, caused for example by simple forgetting, suboptimal perception conditions, misleading postevent information, or biased instructions (see, e.g., Clifford & Bull, 1978; Davies, Ellis, & Shepherd, 1981; Lloyd-Bostock & Clifford, 1983; Loftus, 1979; Shepherd, Ellis, & Davies, 1982; Wegener, Köhnken, & Steller, in press; Wells & Loftus, 1984, for reviews of this line of research). These factors affect an aspect of the reliability of a statement which will be referred to as the accuracy.