The effect of cross-examination style questions on adult eyewitness accuracy depends on question type and eyewitness confidence.

In adversarial legal systems across the world, witnesses in criminal trials are subjected to cross-examination. The questions that cross-examiners pose to witnesses are often complex and confusing; they might include negatives, double negatives, leading questions, closed questions, either/or questions, or complex syntax and vocabulary. Few psycholegal studies have explored the impact of such questions on the accuracy of adult witnesses' reports. In two experiments, we adapted the standard investigative interview procedure to examine the effect of five types of cross-examination style questions on witness accuracy and confidence. Participants watched a mock crime video and answered simple-style questions about the event. Following a delay, participants answered both cross-examination style questions and simple questions about the event. Negative and Double negative questions sometimes impaired the accuracy of witnesses' responses during cross-examination, whereas Leading and Leading-with-feedback questions did not impair - but sometimes enhanced - the accuracy of witnesses' responses. Participants who were better at discriminating between correct and incorrect responses on the initial memory test were more likely to improve the accuracy of their reports during cross-examination. Our findings suggest that the effect of cross-examination style questions on eyewitness accuracy depends on question type and witnesses' confidence in their responses.