REVERSIBILITY OF THE HINDSIGHT BIAS - MANIPULATION OF EXPERIMENTAL DEMANDS

A hindsight bias is found when ratings made after outcome feedback differ from ratings made before feedback. Cognitive processes, motivational factors, and demand characteristics have all been identified as possible mediators of the effect. In the first of two experiments, providing subjects with a forewarning with or without a passage that was predicted to have caused it to be ineffective in previous research failed to reduce the bias. Subsequent instructions to produce the bias inflated the effect, whereas instructions to not produce the bias did not alter ratings. In the second experiment, experimental demands were altered by forewarning subjects about a “never-knew-that“ effect. The results from Experiment 2 replicated the failure of the forewarning instructions. However, the hindsight bias was removed by instructions to produce a “never-knew-that” effect. The implications of these two experiments for research into the hindsight bias were discussed. © 1993 Academic Press, Inc.