Effects of amount of information on judgment accuracy and confidence

When a person evaluates his or her confidence in a judgment, what is the effect of receiving more judgment-relevant information? We report three studies that show when judges receive more information, their confidence increases more than their accuracy, producing substantial confidence-accuracy discrepancies. Our results suggest that judges do not adjust for the cognitive limitations that reduce their ability to use additional information effectively. We place these findings in a more general framework of understanding the cues to confidence that judges use and how those cues relate to accuracy and calibration. (C) 2008 Elsevier Inc. All rights reserved.