🤖 AI Summary
This study investigates how individual differences drive the spontaneous emergence and sustained stability of hierarchical structures in multi-agent systems through local interactions. Employing an agent-based modeling (ABM) approach, the research simulates dynamic processes involving reproduction, competition, and cooperation, and quantifies hierarchical directionality using complex network analysis and the trophic incoherence (TI) metric. The findings reveal that the magnitude of intergenerational mutation is the dominant factor determining long-term hierarchical stability, substantially outweighing the influence of initial heterogeneity. Notably, even in initially homogeneous populations, minute differences can be amplified through simple interaction rules, leading to the self-organized formation of structural inequality. This work elucidates the mechanism by which hierarchical order can emerge from bottom-up interactions without any preordained design.
📝 Abstract
A central premise in evolutionary biology is that individual variation can generate information asymmetries that facilitate the emergence of hierarchical organisation. To examine this process, we develop an agent-based model (ABM) to identify the minimal conditions under which hierarchy arises in dynamic multi-agent systems, focusing on the roles of initial heterogeneity and mutation amplitude across generations. Hierarchical organisation is quantified using the Trophic Incoherence (TI) metric, which captures directional asymmetries in interaction networks. Our results show that even small individual differences can be amplified through repeated local interactions involving reproduction, competition, and cooperation, but that hierarchical order is markedly more sensitive to mutation amplitude than to initial heterogeneity. Across repeated trials, stable hierarchies reliably emerge only when mutation amplitude is sufficiently high, while initial heterogeneity primarily affects early formation rather than long-term persistence. Overall, these findings demonstrate how simple interaction rules can give rise to both the emergence and persistence of hierarchical organisation, providing a quantitative account of how structured inequality can develop from initially homogeneous populations.