Data from: Payoff-based learning explains the decline in cooperation in public goods games

Economic games such as the public goods game are increasingly being used to measure social behaviours in humans and non-human primates. The results of such games have been used to argue that people are pro-social, and that humans are uniquely altruistic, willingly sacrificing their own welfare in order to benefit others. However, an alternative explanation for the empirical observations is that individuals are mistaken, but learn, during the game, how to improve their personal payoff. We test between these competing hypotheses, by comparing the explanatory power of different behavioural rules, in public goods games, where individuals are given different amounts of information. We find: (i) that individual behaviour is best explained by a learning rule that is trying to maximize personal income; (ii) that conditional cooperation disappears when the consequences of cooperation are made clearer; and (iii) that social preferences, if they exist, are more anti-social than pro-social.

公共物品博弈（public goods game）等经济学博弈正日益被用于量化人类与非人类灵长类动物的社会行为。此类博弈的研究结果常被用于佐证人类具有亲社会倾向，且人类是独一无二的利他主义者——甘愿牺牲自身福利以惠及他人。然而，针对这些实证观测结果存在另一种解释：个体初始认知存在偏差，但会在博弈过程中学习如何提升自身收益。本研究通过在设置不同信息层级的公共物品博弈中对比不同行为规则的解释力，对这两种竞争性假说展开检验。研究得到如下结论：（1）个体行为的最优解释模型为以最大化个人收入为目标的学习规则；（2）当合作的后果被清晰阐明后，条件合作行为便会消失；（3）即便存在社会偏好，其也更多表现为反社会而非亲社会的倾向。