Indirect reciprocity under opinion synchronization.

Area of Science:

• Evolutionary game theory
• Social psychology
• Behavioral economics

Background:

• Human cooperation is extensive, often explained by indirect reciprocity.
• Social norms and reputation management are key drivers of cooperation.
• Existing models (public vs. private assessment) yield differing conclusions on cooperation stability.

Purpose of the Study:

• To unify differing results from public and private assessment models of cooperation.
• To identify the core factor determining the stability of cooperation under social norms.
• To investigate the role of opinion correlation in the evolution of cooperation.

Main Methods:

• Development of a unified theoretical framework for cooperation models.
• Mathematical modeling of social norms, reputation, and opinion dynamics.
• Analysis of evolutionary stability conditions for cooperative norms.

Main Results:

• Cooperation stability is determined by the correlation of individual opinions.
• Cooperative norms are not evolutionarily stable when individual opinions are statistically independent.
• Group norms and social interaction structures influence opinion correlation.

Conclusions:

• A unified model reconciles public and private assessment findings.
• Opinion correlation is crucial for maintaining cooperation.
• Implications for understanding conformity, polarization, and the evolution of social behavior.