Confidence judgments by actors and observers

We report three experiments comparing confidence judgments made by actors and by observers. In Experiment 1, actors generated qualitative answers (countries of the world) in a country-identification task; in Experiment 2, actors generated quantitative answers (years) in a historical event-dating task. Both actors and observers indicated their confidence in the actors' answers. Actors were significantly less confident in their answers than were observers in the first experiment. This effect was substantially reduced in the second experiment, whether confidence was measured by judged probability or by credible interval width. Experiment 3 used a control task in which actors attempted to bring an outcome variable into a desired range. In contrast to the first two experiments, actors in the control task were more confident than observers. Because subjects were generally overconfident in all three experiments, the present results demonstrate that the use of observers can reduce or exacerbate overconfidence depending on the kind of task and the nature of the event or possibility under evaluation. (C) 1997 by John Wiley & Sons, Ltd.