Juror Need for Cognition and Sensitivity to Methodological Flaws in Expert Evidence1

This study examined whether need for cognition (NC) moderated jurors' sensitivity to methodological flaws in expert evidence. Jurors read a sexual harassment trial summary in which the plaintiff's expert presented a study that varied in ecological validity, general acceptance, and internal validity. High NC jurors found the defendant liable more often and evaluated expert evidence quality more favorably when the expert's study was internally valid vs. missing a control group; low NC jurors did not. Ecological validity and general acceptance did not affect jurors' judgments. Ratings of expert and plaintiff credibility, plaintiff trustworthiness, and expert evidence quality were positively correlated with verdict. Theoretical implications for the scientific reasoning literature and practical implications for trials containing psychological science are discussed.