Objective
People have the intuition that hunger undermines social cooperation, but experimental tests of this have often produced null results. One possible explanation is that the experimental tasks used are not rich enough to capture the diverse pathways by which social cooperation can be sustained or break down in real life. We studied the effects of hunger on cooperation in two tasks of differential interaction richness.

Methods
We manipulated hunger by asking participants to eat, or refrain from eating, breakfast. Participants in experiment 1 ( n  = 106) played a one-shot Ultimatum Game. Participants in experiment 2 ( n  = 264) played twenty rounds of a Public Goods Game in the same groups of four, ten rounds with the possibility of punishing other group members, and ten without.

Results
In experiment 1, skipping breakfast had no significant effects on either amounts proposed or minimum acceptable offers. In experiment 2, there were multiple different significant effects of the manipulation. No-breakfast participants were more generous in the first round of the game without punishment, and in subsequent rounds, were more influenced by what other group members had done the round before. In the punishment game, no-breakfast participants were also less likely to punish their group-mates than breakfast participants. Consequently, the possibility of punishment was less effective in increasing group cooperation levels in no-breakfast groups.

Conclusion
Replicating earlier findings, we found a null effect of hunger on cooperation in a one-shot Ultimatum Game. However, in our richer Public Goods Game, the dynamics of cooperation differed with hunger, in subtle ways not simply classifiable as hungry participants being ‘more’ or ‘less’ cooperative overall.



中文翻译：

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饥饿会影响多种公共物品游戏中的社会决策，但不会影响最后通Ul游戏

目的
人们有一种直觉，即饥饿破坏了社会合作，但是对此进行的实验检验通常没有结果。一种可能的解释是，所使用的实验任务不够丰富，无法捕捉到可以在现实生活中维持或破坏社会合作的各种途径。我们研究了饥饿对合作的影响，其中包括差异互动丰富性的两个任务。

方法
我们通过要求参与者吃或不吃早餐来操纵饥饿。实验1（ n  = 106）的参与者参加 了一次单打最后通Game游戏。实验2（ n  = 264）在四人一组的同一小组中进行了20场公共物品游戏，十轮有可能惩罚其他小组成员，十轮没有进行。

结果
在实验1中，不吃早餐对建议的金额或可接受的最低出价没有明显影响。在实验2中，该操作有多个不同的显着效果。没有早餐的参与者在比赛的第一轮更加慷慨大方，没有受到惩罚，在随后的几轮中，他们更受其他小组成员之前进行的那轮比赛的影响。在惩罚游戏中，与早餐参与者相比，没有早餐的参与者惩罚队友的可能性也较小。因此，惩罚的可能性在提高无早餐团体的团体合作水平方面不太有效。

结论
重复先前的发现，我们发现饥饿对单发最后通Game游戏中的合作没有影响。但是，在我们更丰富的公共物品博弈中，合作的动力因饥饿而有所不同，其微妙的方式不能简单地归类为饥饿的参与者总体上“更多”或“更少”的合作。