Roles of third parties for achievement of sustainable mutual cooperation in large-scale groups

通过一系列的行为实验和脑成像方法，我们研究了第三方如何在大规模群体中实现可持续的相互合作。这些实验的结果表明：1)人们使用心理理论来评估他人的合作性，并做出是否与他人互动的决定；2)此外，人们自身的合作性和/或社交焦虑也会影响这一决定。我们还发现，从第三方的角度来看，人们普遍对帮助实现相互合作的惩罚者有负面的人际印象。

Using a series of behavioral experiments and brain-imaging method, we investigated how third parties contribute to achieve sustainable mutual cooperation in large-scale groups. The results of these experiments suggest that 1) people estimate others' cooperativeness using "theory of mind" and make decision whether or not to interact with others, 2) in addition, people's own cooperativeness and/or social anxiety also affects the decision. We also found that people from the third party point of view, has generally negative interpersonal impressions to punishers who contributed to achieve mutual cooperation.