Mock jurors' judgments about opposing scientific experts: Do cross-examination, deliberation and need for cognition matter?

The purpose of this study was to determine how cross-examination affects jurors' judgments in a case with opposing experts who differ in quality and whether it might be especially helpful for jurors who are less motivated to process information thoroughly (i.e., low "need for cognition" or NFC). Fifty-five college students listened to a civil trial that included testimony from one high- and one low-quality expert. Half heard cross-examination of both experts, half heard no cross-examination. Participants completed verdicts and ratings of defendant culpability and expert quality before and after deliberating in juries. Culpability ratings were more in support of the high-quality expert after deliberation (compared to pre-deliberation), but this effect was significantly stronger for lower (versus higher) NFC jurors. Furthermore, this interaction was stronger when the jurors did not have the benefit of cross-examination. The cross-examination effect was mediated by quality ratings of the low-quality (but not the high-quality) expert. In practice, this means that cross-examination affects jurors' judgments, especially for jurors less motivated to process testimony thoroughly, by helping jurors recognize a flawed expert witness.