Calibration Trumps Confidence as a Basis for Witness Credibility

Abstract

In the courtroom and in laboratory studies, confident witnesses are viewed as more credible, and thus have more influence on judgments and verdicts, than unconfident witnesses. In two experiments (with college student subjects) we demonstrate that erroneous testimony may damage the credibility of a high-confidence witness more than a low-confidence one. We show that listeners rely on a source's calibration - whether the source's confidence is appropriate to the level of knowledge - rather than confidence when evaluating testimony.

Keywords: evidence, juries

JEL Classification: K4, K41