The Critical Role of Opinion Synchronization in Cooperation Through Reputation - A Generalized Theory of Indirect Reciprocity -

An international research team led by Yosuke Murase of the Discrete Event Simulation Research Team at the RIKEN Center for Computational Science has published a general theoretical framework that unifies various existing models of reputation-based cooperative behavior in society.

This research is expected to contribute to understanding the origins of human social emotions and to the design of mechanisms for achieving large-scale cooperation in society.

The team presented a generalized theory of "indirect reciprocity," a mechanism by which cooperative behavior is maintained through reputations in human societies. While several mathematical models of indirect reciprocity have been proposed, they were studied individually and sometimes reached differing conclusions. This study introduces a mathematical model that generalizes previous theoretical research by focusing on the correlation of opinions held by individuals. It revealed that "sufficient synchronization of opinions" is fundamentally essential for maintaining cooperation in society. This finding may also provide insights into the evolutionary origins of human conformity.

The results of this study were published in the online edition of the scientific journal Proceedings of the National Academy of Sciences (PNAS) on November 21.
DOI: 10.1073/pnas.2418364121