Confirmatory Information Processing in Legal Decision: Effect of Intimate Conviction

A large body of research has focused on legal decision-making in mixed courts of lay and professional judges. However, few studies have been conducted to test the impact on evidence processing of the intimate conviction instruction (ICI), a decision rule based on impression formation used in civil law systems. The influence of the two facets of the ICI (the decision rule and the motivation requirement) on confirmatory information processing (CIP) was studied in a harm-to-person case. Using a methodology combining the simulated juror and CIP paradigms, the decision rule (based on impression vs. rationality) and the motivation requirement (required vs. not required) were manipulated to observe their impact on assimilation and selective exposure biases. Results showed significant interactions of the two facets of the ICI but only on the assimilation bias. These results are discussed in the light of the evidence processes in the context of legal decision-making in criminal courts.