Thomas Kyle A, De Freitas Julian, DeScioli Peter, Pinker Steven
Department of Psychology, Harvard University.
Department of Political Science, Stony Brook University.
J Exp Psychol Gen. 2016 May;145(5):621-629. doi: 10.1037/xge0000153. Epub 2016 Feb 25.
The more potential helpers there are, the less likely any individual is to help. A traditional explanation for this bystander effect is that responsibility diffuses across the multiple bystanders, diluting the responsibility of each. We investigate an alternative, which combines the volunteer's dilemma (each bystander is best off if another responds) with recursive theory of mind (each infers what the others know about what he knows) to predict that actors will strategically shirk when they think others feel compelled to help. In 3 experiments, participants responded to a (fictional) person who needed help from at least 1 volunteer. Participants were in groups of 2 or 5 and had varying information about whether other group members knew that help was needed. As predicted, people's decision to help zigzagged with the depth of their asymmetric, recursive knowledge (e.g., "John knows that Michael knows that John knows help is needed"), and replicated the classic bystander effect when they had common knowledge (everyone knowing what everyone knows). The results demonstrate that the bystander effect may result not from a mere diffusion of responsibility but specifically from actors' strategic computations.
潜在的帮助者越多，任何一个个体提供帮助的可能性就越小。对于这种旁观者效应的传统解释是，责任分散到多个旁观者身上，从而稀释了每个人的责任。我们研究了另一种解释，它将志愿者困境（如果另一个人做出回应，每个旁观者的情况最佳）与递归心理理论（每个人推断其他人对自己所知信息的了解情况）相结合，以预测当行动者认为其他人会被迫提供帮助时，他们会策略性地逃避。在3个实验中，参与者对一个（虚构的）需要至少一名志愿者帮助的人做出回应。参与者被分成2人或5人的小组，并对其他小组成员是否知道需要帮助有不同的信息。正如预测的那样，人们提供帮助的决定随着他们不对称的递归知识深度而波动（例如，“约翰知道迈克尔知道约翰知道需要帮助”），并且当他们有共同知识（每个人都知道其他人知道的事情）时，重复了经典的旁观者效应。结果表明，旁观者效应可能不是仅仅由责任分散导致的，而是具体由行动者的策略性计算导致的。
