Abstract

The present study aims to test whether the coherence of a juror’s mental model of a case is a function of the decisional phase (pre- or post-decision) in which inconsistent evidence is presented. Based on psychological and neurological theories of decision-making, it was hypothesized that inconsistent information could cause a shift in juror's verdict preference more often when the information is presented after the decision is almost shaped than when it is presented while the decision is still shaping. With an actual criminal case in which the evidence was generally skewed toward the guilty verdict, three hundred collage students established an initial verdict preference and rated the likelihood of guilt of the defendant after reading a description of the facts and the first two pieces of strongly incriminating evidence. Participants then read the rest of the evidence, and decided on a final verdict and re-rated the likelihood of guilt. One of the two types of inconsistent evidence, one weakening the prosecution's case and the other supporting the defense's case, was presented either soon after the initial verdict preference was made or just before the final verdict was made. The initial guilty preference shifted in the final verdict more often, and the rated likelihood of guilt decreased more with the late presentation than with the early presentation of the inconsistent evidence. Implications for juror's decision-making in court are discussed.