Brain Science Institute, Tamagawa University, Machida 194-8610, Japan.
Graduate School of International Corporate Strategy, Hitotsubashi University, Tokyo 101-8439, Japan.
Sci Rep. 2016 Jun 14;6:27824. doi: 10.1038/srep27824.
Despite the repeatedly raised criticism that findings in economic games are specific to situations involving trivial incentives, most studies that have examined the stake-size effect have failed to find a strong effect. Using three prisoner's dilemma experiments, involving 479 non-student residents of suburban Tokyo and 162 students, we show here that stake size strongly affects a player's cooperation choices in prisoner's dilemma games when stake size is manipulated within each individual such that each player faces different stake sizes. Participants cooperated at a higher rate when stakes were lower than when they were higher, regardless of the absolute stake size. These findings suggest that participants were 'moral bargain hunters' who purchased moral righteousness at a low price when they were provided with a 'price list' of prosocial behaviours. In addition, the moral bargain hunters who cooperated at a lower stake but not at a higher stake did not cooperate in a single-stake one-shot game.
尽管人们一再批评经济博弈中的发现仅适用于涉及微不足道激励的情况，但大多数研究利益大小效应的研究都未能发现强烈的效应。通过三个涉及东京郊区的 479 名非学生居民和 162 名学生的囚徒困境实验，我们在这里表明，当在每个个体内部操纵利益大小以使每个参与者面临不同的利益大小时，利益大小会强烈影响参与者在囚徒困境博弈中的合作选择。当赌注较低时，参与者的合作率高于当赌注较高时，而与绝对赌注大小无关。这些发现表明，参与者是“道德讨价还价者”，当他们提供了一份亲社会行为的“价目表”时，他们以低价购买了道德正直。此外，在低赌注下合作但在高赌注下不合作的道德讨价还价者并没有在单一赌注的一次性游戏中合作。
