The effect of expert witness testimony and complainant cognitive statements on mock jurors’ perceptions of rape trial testimony

Abstract

This study explores the influence on juror decision-making of expert witness and rape complainant testimony that explains a complainant's counter-intuitive behaviour. A total of 280 participants read a vignette of a date rape scenario containing one of four combinations of conditions: expert witness testimony present or not present and complainant's explanatory statement present or not present. No significant effects were found between conditions for defendant guilt likelihood and complainant credibility or blameworthiness, but the participants judged the defendant as more blameworthy when both the complainant's explanatory statement and the expert witness testimony were present. The participants’ qualitative responses about their reasoning suggest that they were more likely to use evidence-based reasoning in their judgements when expert witness testimony and cognitive statements were present. This emphasises the importance of police and prosecutors finding ways to mitigate the potentially detrimental effects of rape myths when gathering evidence and constructing a case.