For cooperation to evolve, some mechanism must limit the rate at which cooperators are exposed to defectors. Only then can the advantages of mutual cooperation outweigh the costs of being exploited. Although researchers widely agree on this, they disagree intensely about which evolutionary mechanisms can explain the extraordinary cooperation exhibited by humans. Much of the controversy follows from disagreements about the informational regularity that allows cooperators to avoid defectors. Reliable information can allow cooperative individuals to avoid exploitation, but which mechanisms can sustain such a situation is a matter of considerable dispute. We conducted a behavioral experiment to see if cooperators could avoid defectors when provided with limited amounts of explicit information. We gave each participant the simple option to move away from her current neighborhood at any time. Participants were not identifiable as individuals, and they could not track each other's tendency to behave more or less cooperatively. More broadly, a participant had no information about the behavior she was likely to encounter if she moved, and so information about the risk of exploitation was extremely limited. Nonetheless, our results show that simply providing the option to move allowed cooperation to persist for a long period of time. Our results further show that movement, even though it involved considerable uncertainty, allowed would-be cooperators to assort positively and eliminate on average any individual payoff disadvantage associated with cooperation. This suggests that choosing to move, even under limited information, can completely reorganize the mix of selective forces relevant for the evolution of cooperation.

中文翻译：

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通过避免不良行为来维持合作。

为了使合作发展，某种机制必须限制合作者暴露于叛逃者的比率。只有这样，相互合作的优势才能超过被开发的成本。尽管研究人员对此普遍认同，但他们对哪种进化机制可以解释人类所表现出的非凡合作表现出强烈的分歧。许多争议源于对信息规律性的分歧，信息规律性使合作者可以避免叛逃者。可靠的信息可以使合作者避免剥削，但是哪种机制可以维持这种状况则是一个颇有争议的问题。我们进行了一项行为实验，以了解在提供有限数量的明确信息时，合作者是否可以避免叛逃者。我们为每个参与者提供了一个简单的选择，可以随时离开她当前所在的社区。参与者不能被识别为个人，他们无法追踪彼此或多或少合作的倾向。更广泛地讲，参与者没有关于她移动时可能会遇到的行为的信息，因此有关遭受剥削风险的信息极为有限。但是，我们的结果表明，仅提供转移的选择就可以使合作长期持续下去。我们的结果进一步表明，即使涉及很大的不确定性，运动也使潜在的合作者能够积极地进行分类，并且平均消除与合作相关的任何个人收益劣势。这表明即使在信息有限的情况下，也选择移动，