What do you expect?: The influence of people's prior knowledge of crime categories on fact-finding.

Jurors have accumulated prior knowledge of crime categories that influences their verdict choices (V. L. Smith, 1991, 1993). The present research investigates whether this prior knowledge also influences the fact-finding process by operating as an expectancy for information processing. Consistent with the expectancy hypothesis, Study 1 demonstrated that people are more susceptible to misleading information that is perceived to be typical of the crime in question than misleading information that is atypical. Studies 2 and 3 revealed that people's intrusion errors also contain more typical than atypical information. These results indicate that people's prior knowledge of crime categories does indeed serve as an expectancy for fact-finding. Thus, prior knowledge plays a broader role than previously appreciated. The implications of this breadth are discussed.