We hypothesized that the activation of a counterfactual mind-set minimizes group decision errors caused by the failure of groups to discuss unshared, uniquely held information. In two experiments, we manipulated the salience of counterfactual thoughts in a pre-task scenario and then had groups of three individuals discuss a murder mystery case. In both experiments, counterfactual mind-sets increased the discussion of unshared information and helped groups to identify the correct murder suspect. These results emerged regardless of whether the direction of the counterfactual thoughts was upward (Experiment 1) or downward (Experiment 2), suggesting that it is the process of thinking counterfactually, and not the content of the counterfactuals, that improves group decision making.
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