Data from: Interacting with the enemy: indirect effects of personality on conspecific aggression in crickets

In animal contests, individuals respond plastically to the phenotypes of the opponents that they confront. These “opponent”—or “indirect”—effects are often repeatable, for example, certain opponents consistently elicit more or less aggressiveness in others. “Personality” (repeatable among-individual variation in behavior) has been proposed as an important source of indirect effects. Here, we repeatedly assayed aggressiveness of wild-caught adult male field crickets Gryllus campestris in staged dyadic fights, measuring aggressiveness of both contestants. Measurements of their personality in nonsocial contexts (activity and exploration behavior) enabled us to ask whether personality caused indirect effects on aggressiveness. Activity, exploration, and aggressiveness were positively associated into a behavioral syndrome eliciting aggressiveness in conspecifics, providing direct evidence for the role of personality in causing indirect effects. Our findings imply that a multivariate view of phenotypes that includes indirect effects greatly improves our ability to understand the ecology and evolution of behavior.

在动物争斗行为中，个体可对其所遭遇对手的表型产生可塑性响应。这类“对手效应”（或称“间接效应”）通常具有可重复性——例如，特定的对手总能在其他个体身上诱发程度不一的攻击行为。“个性”（行为的个体间可重复性变异）被认为是间接效应的重要来源之一。本研究通过设置标准化成对争斗实验，对野外捕获的成年雄性田野蟋蟀（*Gryllus campestris*）的攻击行为进行反复测定，并同步记录两名争斗者的攻击强度。通过测定它们在非社会情境下的个性特征（活动能力与探索行为），我们得以探究个性是否会对攻击行为产生间接效应。活动能力、探索行为与攻击行为呈正相关，共同构成行为综合征（behavioral syndrome），能够在同种个体中诱发攻击行为，这为个性在介导间接效应中的作用提供了直接证据。本研究结果表明，纳入间接效应的多变量表型视角，可极大提升我们理解行为生态学与行为演化的能力。