Data from: Conditional cooperation and confusion in public-goods experiments

Economic experiments are often used to study if humans altruistically value the welfare of others. A canonical result from public-good games is that humans vary in how they value the welfare of others, dividing into fair-minded conditional cooperators, who match the cooperation of others, and selfish noncooperators. However, an alternative explanation for the data are that individuals vary in their understanding of how to maximize income, with misunderstanding leading to the appearance of cooperation. We show that (i) individuals divide into the same behavioral types when playing with computers, whom they cannot be concerned with the welfare of; (ii) behavior across games with computers and humans is correlated and can be explained by variation in understanding of how to maximize income; (iii) misunderstanding correlates with higher levels of cooperation; and (iv) standard control questions do not guarantee understanding. These results cast doubt on certain experimental methods and demonstrate that a common assumption in behavioral economics experiments, that choices reveal motivations, will not necessarily hold.

经济学实验常被用于探究人类是否会出于利他主义（altruism）考量他人的福祉。公共品博弈（public-good game）领域的一项经典结论显示，人类在重视他人福祉的程度上存在异质性，可划分为两类：一类是秉持公平理念的条件合作者（conditional cooperator），其合作行为会匹配他人的合作水平；另一类是自利型非合作者（selfish noncooperator）。然而，针对该实验数据存在另一种解释：个体在理解如何实现收益最大化的能力上存在差异，对博弈规则的误解会催生合作的表象。本研究证实：(i) 当与计算机进行博弈时，人类仍会划分出相同的行为类型——毕竟人类本不可能在意计算机的福祉；(ii) 人类与计算机博弈、与人类博弈时的行为存在相关性，且这种相关性可通过个体在收益最大化理解能力上的差异来解释；(iii) 对博弈规则的误解与更高水平的合作行为呈正相关；(iv) 常规的理解性控制问题无法确保受试者真正掌握博弈规则。上述结论对部分实验方法提出了质疑，同时证明了行为经济学实验中的一项常见假设——即个体的选择可直接反映其动机——未必成立。