Reciprocity as the Foundational Substrate of Society: How Reciprocal Dynamics Scale into Social Systems

A major bottleneck in multi-agent AI is the lack of simulateable models for the bottom-up emergence of social structure under realistic behavioral constraints. Similarly, many foundational theories in economics and sociology including the concepts of "institutions" and "norms" tend to describe social structures post hoc, often relying on implicit assumptions of shared culture, morality, or symbolic agreement. These concepts are often treated as primitives rather than reconstructed from agent-level behavior, leaving both their origins and operational definitions under-specified. To address this, we propose a three-stage bottom-up framework: Reciprocal Dynamics, capturing individual-level reciprocal exchanges; Norm Stabilization, the consolidation of shared expectations; and Institutional Construction, the externalization of stable patterns into scalable structures. By grounding social emergence in agent-level reciprocity, our framework enables the systematic exploration of how moral, cultural, and institutional structures emerge from cognitively minimal interactions.