title: Group discussion improves lie detection.
abstract: Groups of individuals can sometimes make more accurate judgments than the average individual could make alone. We tested whether this group advantage extends to lie detection, an exceptionally challenging judgment with accuracy rates rarely exceeding chance. In four experiments, we find that groups are consistently more accurate than individuals in distinguishing truths from lies, an effect that comes primarily from an increased ability to correctly identify when a person is lying. These experiments demonstrate that the group advantage in lie detection comes through the process of group discussion, and is not a product of aggregating individual opinions (a "wisdom-of-crowds" effect) or of altering response biases (such as reducing the "truth bias"). Interventions to improve lie detection typically focus on improving individual judgment, a costly and generally ineffective endeavor. Our findings suggest a cheap and simple synergistic approach of enabling group discussion before rendering a judgment.
authors.affiliation: Booth School of Business, University of Chicago, Chicago, IL 60637 nklein@chicagobooth.edu epley@chicagobooth.edu.
authors.forename: Nadav
authors.initials: N
authors.lastname: Klein
authors.affiliation: Booth School of Business, University of Chicago, Chicago, IL 60637 nklein@chicagobooth.edu epley@chicagobooth.edu.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Epley
mesh_terms: D003198:Computer Simulation; D008192:Deception; D005260:Female; D006126:Group Processes; D006801:Humans; D007600:Judgment; D008014:Lie Detection / Q000523:psychology*; D008297:Male; D008960:Models, Psychological
keywords: group decision-making; lie detection; mind reading; social cognition; wisdom of crowds