Stranger danger: A meta-analysis of the dear enemy hypothesis

The dear enemy hypothesis predicts that territorial individuals will be less aggressive toward known neighbors than to strangers. This hypothesis has been well studied and there is a wealth of data demonstrating its prevelance among some taxa. However, a quantitative synthesis is needed to test the generality of the phenomenon, identify key mechanisms driving the behavior, and guide future research. Here we made a comprehensive collection of Dear Enemy data from 138 studies representing 105 species spread over eight taxonomic classes. The associated paper finds that Dear Enemy is a common phenomenon but drivers of this phenomenon are still understudied and current knowledge is unable to disentangle competing hypotheses of drivers of this behavior.亲爱的敌人假说（Dear Enemy Hypothesis）预测，领地个体对熟悉邻居的攻击性会低于对陌生个体的攻击性。该假说已得到广泛研究，现有大量数据证实其在部分生物类群中存在普遍性。然而，目前仍需开展定量综合分析，以检验该现象的普适性、明确驱动该行为的关键机制，并为后续研究提供方向。本研究全面收集了138项研究的相关数据，涵盖8个分类纲、105个物种，所有数据均围绕亲爱的敌人效应展开。相关研究论文显示，亲爱的敌人现象较为普遍，但该现象的驱动因素仍未得到充分探究，现有认知尚无法厘清该行为驱动因素的各类竞争性假说。