ABSTRACT
There are different reasons why people form, join, or are assigned to groups, but an important one is to perform some task together. For example, students are assigned to groups to write an essay or research report together, teams in companies are formed to improve customer satisfaction, military teams perform operations on enemy territory, and groups of friends decide to organize a party together. Often, these groups are formed because their specific task cannot be accomplished by an individual working alone. At other times the task could in principle be done by individuals, but it is believed that performing it in a group is somehow more effective or efficient (or more fun). For groups of both kinds, the ultimate goal therefore is to perform well, and group performance is a topic that has been studied in social psychology since its beginnings (e.g., Ringelmann, 1913; Triplett, 1898).
