Members of a social species need to make appropriate decisions about who, how, and when to interact with others in their group. However, it has been difficult for researchers to detect the inputs to these decisions and, in particular, how much information individuals actually have about their social context. We present a method that can serve as a social assay to quantify how patterns of aggression depend upon information about the ranks of individuals within social dominance hierarchies. Applied to existing data on aggression in 172 social groups across 85 species in 23 orders, it reveals three main patterns of rank-dependent social dominance: the downward heuristic (aggress uniformly against lower-ranked opponents), close competitors (aggress against opponents ranked slightly below self), and bullying (aggress against opponents ranked much lower than self). The majority of the groups (133 groups, 77%) follow a downward heuristic, but a significant minority (38 groups, 22%) show more complex social dominance patterns (close competitors or bullying) consistent with higher levels of social information use. These patterns are not phylogenetically constrained and different groups within the same species can use different patterns, suggesting that heuristic use may depend on context and the structuring of aggression by social information should not be considered a fixed characteristic of a species. Our approach provides opportunities to study the use of social information within and across species and the evolution of social complexity and cognition.

社会物种的成员需要就谁、如何以及何时与群体中的其他人互动做出适当的决定。然而，研究人员很难检测这些决策的输入，特别是个人实际上拥有多少关于其社会背景的信息。我们提出了一种方法，可以作为一种社会分析来量化攻击模式如何依赖于社会统治等级中个人的等级信息。应用到 23 个目的 85 个物种的 172 个社会群体的攻击行为的现有数据中，它揭示了排名依赖的社会支配地位的三种主要模式：向下启发式（统一攻击排名较低的对手）、接近竞争者（攻击排名稍低的对手）低于自己）和欺凌（攻击排名远低于自己的对手）。大多数群体（133 个群体，77%）遵循向下启发式，但少数群体（38 个群体，22%）表现出更复杂的社会主导模式（紧密的竞争者或欺凌），这与较高水平的社会信息使用相一致。这些模式不受系统发育的限制，同一物种内的不同群体可以使用不同的模式，这表明启发式的使用可能取决于背景，并且社会信息的攻击结构不应被视为物种的固定特征。我们的方法提供了研究物种内部和物种之间社会信息的使用以及社会复杂性和认知的演变的机会。