The influence of member heterogeneity on dyad judgment: Are two heads better than one?

An experiment is conducted to test the effect of the degree of heterogeneity in individual member judgments on the accuracy of judgments made by dyads. Predictions are made about how (1) homogeneity versus heterogeneity in judgments and (2) task instruction interact to affect a group's judgmental accuracy in average price-estimation tasks. Results indicate that dyads were not more accurate than the average dyad member or than the better member. However, increases in accuracy (relative to the accuracy of the better member of the dyad) occurred more often in dyads whose members were heterogeneous in their prior individual judgments than they did in dyads whose members were more homogeneous. When provided with instructions, heterogeneous dyads improved in accuracy to a greater degree than did homogeneous dyads.

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