Explanations of Individual-Group Performance Differences

Abstract

The issues of whetherornotgroups outperform individuals on multiple-item problem-solving tasks and the size of the performance difference were discussed. The level of analysis was found to be an important consideration-groups outperformed their best member at the aggregate level of analysis (i.e., total score), but often failed to perform at the level of the best member on individual items. It was argued that groups outperform individuals at the aggregate level because group members often have complementary bases of knowledge that can compensate for each other's weaknesses and because of "synergistic " effects in groups. Implications for using groups as decision-making units in applied contexts were discussed.