Data from: A simple behavioral model predicts the emergence of complex animal hierarchies

Social dominance hierarchies are widespread, but little is known about the mechanisms that produce non-linear structures. In addition to despotic hierarchies, where a single individual dominates, shared hierarchies exist where multiple individuals occupy a single rank. In vertebrates, these complex dominance relationships are thought to develop from interactions that require higher cognition, but similar cases of shared dominance have been found in social insects. Combining empirical observations with a modeling approach, we show that all three hierarchy structures-linear, despotic, and shared-can emerge from different combinations of simple interactions present in social insects. Our model shows that a linear hierarchy emerges when a typical winner-loser interaction (dominance biting) is present. A despotic hierarchy emerges when a policing interaction is added that results in the complete loss of dominance status for an attacked individual (physical policing). Finally, a shared hierarchy emerges with the addition of a "winner-winner" interaction that results in a positive outcome for both interactors (antennal dueling). Antennal dueling is an enigmatic ant behavior that has previously lacked a functional explanation. These results show how complex social traits can emerge from simple behaviors without requiring advanced cognition.

社会优势等级（Social Dominance Hierarchies）广泛存在，但其非线性结构的形成机制仍有待深入阐明。除了由单个个体占据统治地位的专制型等级（despotic hierarchies）之外，还存在共享型等级（shared hierarchies）——即多个个体共享同一等级位次。在脊椎动物中，这类复杂的优势关系以往被认为源于需要较高认知能力的互动行为，但在社会性昆虫中也发现了类似的共享优势等级现象。本研究结合实证观测与建模方法，证明三种等级结构——线性等级、专制型等级与共享型等级——均可通过社会性昆虫中存在的不同简单互动组合自发涌现。模型显示，当存在典型的胜-负互动（winner-loser interaction，优势啃咬（dominance biting））时，会形成线性等级结构；若新增惩罚性互动（physical policing，物理惩罚），即攻击者可完全剥夺被攻击者的优势地位，则会形成专制型等级结构；最后，若新增“胜-胜”互动模式，即互动双方均获得正向收益的触角决斗（antennal dueling），则会形成共享型等级结构。触角决斗是一种长期以来缺乏合理解释的神秘蚂蚁行为。本研究结果揭示了复杂的社会性状如何通过简单行为自发涌现，而无需依赖高级认知能力。