Group discussion often becomes one-sided and confirmatory, with poor decisions as the unfortunate outcome. Here we examine whether intergroup competition amplifies or mitigates effects of individual versus team reward on information sharing biases and group decision quality. Individuals (N = 309) in 103 interacting groups were given private information on four decision alternatives and discussed a joint decision. Private information was distributed such that groups faced a “hidden profile” in which pushing for initial preferences and commonly held information prohibits the group from finding the best alternative. Group members were rewarded for team or individual performance, and groups faced intergroup competition or not. Whereas intergroup competition did not influence common-information bias, we find that when intergroup competition is absent, groups under individual (versus team) reward have stronger preference-consistency bias and make poorer decisions. When intergroup competition is present, however, groups under individual reward perform as good as groups under team reward. Results resonate with the possibility that intergroup competition overshadows within-group rivalry, and can promote even-handed discussions within small groups of decision-makers.

小组讨论通常是单方面的和确认性的，糟糕的决定是不幸的结果。在这里，我们研究了群体间竞争是否放大或减轻了个人与团队奖励对信息共享偏见和群体决策质量的影响。个人（N （= 309）在103个交互的组中获得了有关四个决策方案的私人信息，并讨论了联合决策。散布私人信息，使团体面临“隐藏的特征”，在这种情况下，追求初始偏好和普遍持有的信息会阻止团体寻找最佳选择。小组成员因团队或个人表现而获得奖励，而小组是否面临小组间竞争。尽管群体间竞争不影响公共信息偏见，但我们发现，当群体间竞争不存在时，个人（对团队）奖励下的群体具有更强的偏好一致性偏见，并且做出较差的决策。但是，当存在小组间竞争时，个人奖励下的小组表现与团队奖励下的小组一样好。