Opening up a can of worms: how do decision-makers decide when witnesses are telling the truth?

Correctly determining witness credibility is integral to a fair trial. Assessments of credibility made by the triers of fact are made, amongst other things, by reference to behavioural stereotypes that are commonly thought to be associated with lying and truth-telling. These stereotypes are worthless but pervasive. In this study, potential jurors were given information such as would be given by way of judicial direction and/or expert testimony on those behavioural indicia that are useful in detecting deception. Major changes in perceptions of what does and does not work were found. This has significant implications for the conduct of criminal trials. Recommendations are presented which, it is argued, can be of real, practical, assistance in enabling decision-makers to assess the credibility of witnesses. © 2013 The Australian and New Zealand Association of Psychiatry, Psychology and Law