This study examined the effects that a defendant's pleading of the fifth amendment during a criminal trial had on simulated juror's decisions regarding verdict, likelihood of guilt, certainty of guilt, sentence severity, and perceptions of the defendant's character. One hundred fifty-five undergraduate psychology students read one of three versions of a transcript, based on a trial of a man charged with theft, in which the defendant did not plead the fifth (control), plead the fifth, or plead the fifth possibly for reasons other than hiding involvement in the crime (i.e. having an affair). Results showed that the two fifth amendment conditions found the defendant to be more likely guilty than the control condition. Also, a factor analysis suggested that an honest and a relaxed dimension best described the defendant's character. In addition, it was discovered that perceptions of the defendant's honesty mediated the effects of perceived likelihood of guilt. / Department of Psychological Science

This thesis describes research about potential jurors' beliefs about children as witnesses. Jurors' knowledge of memory, suggestibility and child sexual abuse was collected and analysed. The aim was to identify strengths or weaknesses in jurors' knowledge to further inform discussion on whether experts should provide evidence to jurors about children's memory, suggestibility and behaviour, in cases which involve child witnesses. This research showed that jurors from both Australia and America had correct beliefs about some characteristics of child witnesses, however they also had incorrect beliefs. The main areas where both Australian and American jurors' beliefs were incorrect was in the suggestibility and interrogation category, and the memory and ability to testify category; however both had some incorrect beliefs with respect to reactions to sexual abuse and disclosure about sexual abuse categories. These findings support the proposition that expert evidence would be beneficial in improving jurors' knowledge of child witnesses, particularly in the areas of children's suggestibility and responses to interrogation. Jurors' assessment of children's testimony is fundamental in some criminal cases, and therefore information obtained in this study has implications for any case where a child witness testifies.