Dirty tricks of cross-examination: The influence of conjectural evidence on the jury.

A mock jury study was conducted to test the hypothesis that perceptions of a witness can be biased by presumptuous cross-examination questions. A total of 105 subjects read a rape trial in which the cross-examiner asked a question that implied something negative about the reputation of either the victim or an expert. Within each condition, the question was met with either a denial, an admission, or an objection from the witness's attorney. Results indicated that although ratings of the victim's credibility were not affected by the presumptuous question, the expert's credibility was significantly diminished—even when the question had elicited a denial or a sustained objection. Conceptual and practical implications of these findings are discussed.