Effective coordination of group actions underlies the success of group-living organisms. Recent studies of animal personality have shown that groups composed of individuals with different behavioral propensities can outperform uniform groups in a range of different tasks, but we have only a rudimentary understanding of how differences in individual behavior influence the behavior of the group as a whole. In this study, we use natural variation in behavioral propensity among morphologically distinct worker castes of the small carpenter ant Camponotus yamaokai to shed new light on this. Iterative testing indicated that ants displayed consistent behavioral differences among individuals and between castes, with major workers exhibiting a lower exploratory tendency than minors. By constructing groups of different caste composition and quantifying their performance in the task of colony emigration, we show that group performance is an asymmetric humped function of caste ratio, with optimal performance achieved by groups with natural caste ratios. Using a simulation model based on our empirical data, we demonstrate that interindividual differences in social attraction and exploratory tendency are sufficient to explain the observed patterns. Our results provide new insights into how group performance in collective tasks can vary with group composition.

中文翻译：

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功能异质性促进工蚁有效的集体任务表现

群体行动的有效协调是群体生物成功的基础。最近对动物人格的研究表明，由具有不同行为倾向的个体组成的群体可以在一系列不同的任务中胜过统一的群体，但我们对个体行为的差异如何影响整个群体的行为只有初步的了解。在这项研究中，我们利用小木工蚁弓背蚁（Camponotus yamaokai）形态上不同的工蚁种姓之间行为倾向的自然变异，为这一问题提供了新的线索。迭代测试表明，蚂蚁在个体之间和种姓之间表现出一致的行为差异，大工蚁的探索倾向低于未成年工蚁。通过构建不同种姓构成的群体并量化他们在殖民地移民任务中的表现，我们表明群体表现是种姓比例的不对称驼峰函数，具有自然种姓比例的群体可以实现最佳表现。使用基于我们的经验数据的模拟模型，我们证明了社会吸引力和探索倾向的个体差异足以解释观察到的模式。我们的结果提供了新的见解，让我们了解集体任务中的团队绩效如何随团队组成的变化而变化。