Prior Conviction Evidence: Harmful or Irrelevant? A Literature Review

Abstract

Experimental studies on the effect of prior conviction evidence (PCE) on judgments of guilt are conflicting, ranging from an increase of guilt to a decrease of guilt, depending on certain boundary conditions. The overall effect of PCE seems to be small and likely depends on moderators. Due to small samples or because of lack of experimental manipulations, these moderators could not yet be meta-analyzed. This literature review follows up on these moderators with the aim to provide a clearer understanding under which circumstances PCE could harm or benefit the defendant, or when prior convictions of the defendant are completely irrelevant. Existing literature on PCE was reviewed to identify potential moderators and to provide directions for future research. Identified moderators were categorized into PCE characteristics (similarity and seriousness of PCE, PCE quantity, admissibility, and limiting instructions), case characteristics (ambiguity, seriousness of current offense), and methodological moderators (salience, control condition and manipulation checks, sample, individual vs. group decisions, richness of stimulus materials). PCE effects seem to depend on various factors that greatly narrow the influence of PCE. Therefore, an integrative perspective is proposed for future studies that take legal decision-making theories and information processing theories into account.