Although dominance hierarchies occur in most societies, our understanding of how these power structures influence individual investment in cooperative and competitive behaviours remains elusive. Both conflict and cooperation in animal societies are often environmentally regulated, yet how individuals alter their cooperative and competitive investments as environmental quality changes remain unclear. Using game theoretic modelling, we predict that individuals of all ranks will invest more in cooperation and less in social conflict in harsh environments than individuals of the same ranks in benign environments. Counterintuitively, low-ranking subordinates should increase their investment in cooperation proportionally more than high-ranking dominants, suggesting that subordinates contribute relatively more when facing environmental challenges. We then test and confirm these predictions experimentally using the Asian burying beetle Nicrophorus nepalensis. Ultimately, we demonstrate how social rank modulates the relationships between environmental quality and cooperative and competitive behaviours, a topic crucial for understanding the evolution of complex societies.

中文翻译：

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社会等级调节环境质量如何影响动物社会内部的合作和冲突

尽管大多数社会都存在支配等级，但我们对这些权力结构如何影响个人对合作和竞争行为的投资的理解仍然难以捉摸。动物社会中的冲突和合作通常都受环境监管，但随着环境质量的变化，个人如何改变他们的合作和竞争投资仍不清楚。使用博弈论模型，我们预测在恶劣环境中，所有级别的个人将比在良性环境中的相同级别的个人更多地投资于合作，更少地投入到社会冲突中。与直觉相反，下级下属应该比上级主导者按比例增加合作投资，这表明下属在面临环境挑战时做出的贡献相对更大。然后，我们使用亚洲埋葬甲虫 Nicrophorus nepalensis 通过实验测试和确认这些预测。最终，我们展示了社会等级如何调节环境质量与合作和竞争行为之间的关系，这是理解复杂社会演变的关键主题。