Are we nice(r) to nice(r) people?—An experimental analysis
通过实验研究人们在匿名决策环境中能否可靠地识别合作者，发现高捐赠者主要通过与其他高捐赠者合作获得高于平均的预期收益，而群体归属无关紧要。
Abstract We experimentally investigate whether individuals can reliably detect cooperators (the nice(r) people) in an anonymous decision environment involving “connected games.” Participants can condition their choices in an asymmetric prisoners’ dilemma and a trust game on past individual (their partner's donation share to a self-selected charity) and social (whether their partner belongs to a group with high or low average donations) information. Thus, the two measures of niceness are the individual donation share in the donation task, and the cooperativeness of one's choice in the two games. We find that high donors achieve a higher-than-average expected payoff by cooperating predominantly with other high donors. Group affiliation proved to be irrelevant.