Inter-role reciprocity in evolutionary trust game on square lattices

2025-08-08

AI Summary

Natural role differentiation between trustors and trustees is difficult to achieve within a single population, hindering the study of spatial reciprocity in trust games. Method: We propose a dual-role alternating assignment framework on a square lattice, strictly separating trustors and trustees topologically to decouple intra-role learning from inter-role interaction. Contribution/Results: We first demonstrate that, at intermediate return ratios, trustors and trustees self-organize into inter-role spatial clusters, sustaining trust through local reciprocity; however, excessively high or low return ratios disrupt role coexistence and impede trust evolution. This paradigm not only clarifies the critical role of spatial structure in trust emergence but also establishes a novel spatial analytical methodology applicable to general bipartite games. By enabling scalable, topology-aware modeling, our approach provides a foundational framework for evolutionary trust research.

Technology Category

• Game Theory and Economic Paradigms: Cooperative Game Theory
• Multiagent Systems: Mechanism Design
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust

Application Category

• Economics, Online Markets and Human Computation: Trust and reliance of crowd workers and data experts on GenAI
• Web Mining and Content Analysis: Models for Web evolution
• Responsible Web: Machine-in-the-loop, human agency and autonomy

Abstract

Simulating bipartite games, such as the trust game, is not straightforward due to the lack of a natural way to distinguish roles in a single population. The square lattice topology can provide a simple yet elegant solution by alternating trustors and trustees. For even lattice sizes, it creates two disjoint diagonal sub-lattices for strategy learning, while game interactions can take place on the original lattice. This setup ensures a minimal spatial structure that allows interactions across roles and learning within roles. By simulations on this setup, we detect an inter-role spatial reciprocity mechanism, through which trust can emerge. In particular, a moderate return ratio allows investing trustors and trustworthy trustees to form inter-role clusters and thus save trust. If the return is too high, it harms the survival of trustees; if too low, it harms trustors. The proposed simulation framework is also applicable to any bipartite game to uncover potential inter-role spatial mechanisms across various scenarios.

Problem

• Simulating bipartite games lacks natural role distinction in single populations
• Square lattice topology enables role alternation for trust game simulation
• Moderate return ratio fosters trust via inter-role spatial reciprocity

Innovation

• Square lattice topology for role distinction
• Diagonal sub-lattices enable strategy learning
• Simulation framework for bipartite games