Group‐beneficial behaviors have presented a long‐standing challenge for evolutionary theory because, although their benefits are available to all group members, their costs are borne by individuals. Consequently, an individual could benefit from “cheating” their group mates by not paying the costs while still reaping the benefits. There have been many proposed evolutionary mechanisms that could favor cooperation (and disfavor cheating) in particular circumstances. However, if cooperation is still favored in some circumstances, then we might expect evolution to favor strategic cooperation, where the level of contribution toward group‐beneficial behavior is varied in response to the social context. To uncover how and why individuals should contribute toward group‐beneficial behavior across social contexts, we model strategic cooperation as an evolutionary game where players can quantitatively adjust the amount they contribute toward group‐beneficial behavior. We find that the evolutionarily stable strategy (ESS) predicts, unsurprisingly, that players should contribute in relation to their relatedness to the group. However, we surprisingly find that players often contribute to cooperation in such a way that their fitness is inverse to their relatedness to the group such that those that contribute to cooperation end up with the same return from group‐beneficial behavior, essentially removing any potential advantage of higher relatedness. These results bring to light a paradox of group‐beneficial cooperation: groups do best when they contain highly related individuals, but those with the highest relatedness to the group will often have the lowest fitness within the group.

中文翻译：

---

战略合作的演变

有益于群体的行为对进化论提出了长期的挑战，因为尽管有益于所有群体的成员，但它们的成本却由个人承担。因此，个人可以通过“欺骗”他们的队友而受益，因为他们无需支付费用，而仍然可以从中受益。已经提出了许多提议的进化机制，这些进化机制可能在特定情况下有利于合作（和不利于作弊）。但是，如果在某些情况下仍偏爱合作，那么我们可能会期望进化会有利于战略合作，因为随着社会背景的变化，对集体受益行为的贡献水平会有所不同。为了揭示个人应如何以及为什么应在整个社会环境中为群体有益行为做出贡献，我们将战略合作建模为一种演化博弈，在此博弈中，玩家可以量化地调整他们对群体有益行为的贡献。我们发现，进化稳定策略（ESS）毫不奇怪地预测，玩家应该根据与团队的亲缘关系做出贡献。但是，我们惊讶地发现，参与者通常以某种方式对合作做出贡献，即他们的适应度与其与团队的亲密关系成反比，以至于那些为合作做出贡献的参与者最终会从群体受益行为中获得相同的回报，从而实质上消除了任何潜在的优势更高的相关性。这些结果揭示了团体与利益合作的悖论：当团体中包含高度相关的个人时，他们的表现最佳，