Participants viewed one of six video-recorded versions of a rape victim's testimony, role-played by a professional actress in one of six versions: Two versions of the testimony, representing a strong and a less strong rape scenario, were given in a free-recall manner with one of three kinds of emotions displayed, termed congruent, neutral and incongruent emotional expressions. Credibility judgements were strongly influenced by the emotions displayed, but not by the content of the story. When video watching was compared to reading a transcript of the testimony, results indicated that perceived credibility was reduced when the witness displayed neutral or incongruent emotions. Story content and displayed emotion contributed equally to estimates of the probability of a guilty verdict. We conclude that perception of credibility is strongly influenced by social stereotypes regarding appropriate emotional expression.

Previous studies have shown that the emotional behavior displayed during testimony may affect the perceived credibility of the witness. The present study compares credibility ratings by Norwegian court judges with those made by lay people. The participants viewed one of three video-recorded versions of a rape victim's statement, role played by a professional actress. The statement was given in a free-recall manner with one of three kinds of emotions displayed, termed congruent, neutral, and incongruent emotional expression. The results show that, in contrast to lay people, the credibility ratings of court judges and their votes for a guilty verdict were not influenced by the emotions displayed by the witness. Results are discussed in terms of professional expertise.

Mock juries of 5-7 jurors viewed one of three video-recorded versions of a rape victim's testimony, role-played by a professional actress. The statement was given in a free-recall manner with one of three kinds of emotions displayed, termed congruent, neutral and incongruent emotional expressions. The juries were requested to reach a decision on items in a short questionnaire, probing the perceived credibility of the witness and judgements of the probability of a guilty verdict. The jurors were then asked to complete the questionnaire a second time, individually and anonymously. A control group filled out the questionnaire individually without preceding jury deliberations. When participants judged credibility and guilt independently, without a preceding jury discussion, the displayed emotions strongly influenced the judgements. However, discussions in the context of the jury strongly attenuated the effect of displayed emotion, with judgements converging on the credibility of a neutral emotional expression as judged by independent participants, and the attenuating effect outlasted the jury-situation. The results are consistent with research within social psychology showing that social stereotypes and prejudices are often neutralised by group discussions.