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 willingly sacrifice their own material payoffs in order to benefit others. However, an alternative explanation for the empirical observations is that individuals are learning, during the game, how to improve their personal pay-off. 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: (1) that individual behavior is best explained by a learning rule that is trying to maximise personal income; (2) that conditional cooperation disappears when the consequences of cooperation are made clearer; and (3) that social preferences, if they exist, are more anti-social than pro-social.

诸如公共物品博弈（public goods game）在内的经济学博弈实验，正愈发广泛地被用于量化人类与非人灵长类动物的社会行为。此类博弈的实验结果常被用以论证人类具备亲社会（pro-social）倾向，即自愿牺牲自身物质收益以惠及他人。但针对此类实证观测结果，另有一派解释认为：个体在博弈过程中会学习如何提升自身的个人收益。本研究通过在设置不同信息量级的公共物品博弈实验中，对比不同行为准则的解释力，对这两种竞争性假说展开检验。研究结果如下：（1）个体行为最能被以最大化个人收入为目标的学习准则所解释；（2）当合作的后果被明确阐释后，条件合作（conditional cooperation）行为便会消失；（3）若社会偏好（social preferences）确实存在，其更偏向反社会（anti-social）而非亲社会。