We use a public good experiment to study how in-group cooperation is affected by payoff-irrelevant information about cooperation in other groups (i.e., descriptive out-group feedback). We find that positive out-group feedback, indicating above-average cooperation, deters low in-group contributors from increasing their contribution towards the in-group average. By contrast, negative out-group feedback, which informs participants about below-average cooperation, deters high in-group contributors from decreasing their contribution towards the in-group average. These two effects work together to dampen contribution patterns associated with conditional cooperation. Further, we show that the effects are stronger for individual-level feedback (comparing individual contributions with the out-group average) than for group-level feedback (comparing total contributions by in-group members with that of other groups). Interestingly, when allowed to avoid out-group feedback information, the propensity to consult the feedback is similar for high and low in-group contributors, suggesting that information acquisition is not always self-serving.

我们使用一项公益实验，研究与其他小组中的合作无关的收益相关信息（即描述性小组外反馈）如何影响小组内部合作。我们发现，积极的群体外反馈（表明合作程度高于平均水平）阻止了群体内低贡献者增加其对群体内平均值的贡献。相比之下，负面的小组外反馈会告知参与者低于平均水平的合作，这会阻止小组内高贡献者降低对小组平均水平的贡献。这两个作用共同作用以抑制与条件合作相关的贡献模式。更多，我们显示，个人水平反馈（将个人贡献与组外平均值进行比较）的效果要比组水平反馈（将组内成员的总贡献与其他组的总贡献进行比较）的效果更强。有趣的是，当被允许避免群体外反馈信息时，对于群体内高贡献者和低群体内贡献者，查阅反馈的倾向是相似的，这表明信息获取并不总是自我服务的。