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Related Experiment Video

Updated: Jul 31, 2025

The Collective Trust Game: An Online Group Adaptation of the Trust Game Based on the HoneyComb Paradigm

The Collective Trust Game: An Online Group Adaptation of the Trust Game Based on the HoneyComb Paradigm

Published on: October 20, 2022

Mutation enhances cooperation in direct reciprocity.

Josef Tkadlec¹, Christian Hilbe², Martin A Nowak^1,3

¹Department of Mathematics, Harvard University, Cambridge, MA 02138.

Proceedings of the National Academy of Sciences of the United States of America

|May 8, 2023

Summary

This summary is machine-generated.

Intermediate mutation rates surprisingly promote cooperation in direct reciprocity. Diversity, not uniformity, enhances cooperative evolution, even with low benefit-to-cost ratios.

Keywords:

direct reciprocity donation game evolution of cooperation mutation rate

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Area of Science:

Evolutionary biology
Game theory
Behavioral ecology

Background:

Direct reciprocity explains cooperation through repeated interactions.
High cooperation requires a benefit-to-cost ratio threshold dependent on memory length.
For one-round memory, this threshold is typically two.

Purpose of the Study:

To investigate the effect of mutation rates on the evolution of cooperation.
To determine if cooperation can evolve with benefit-to-cost ratios below the traditional threshold.
To explore the role of diversity in promoting cooperation.

Main Methods:

Simulations of evolutionary game theory models.
Analysis of direct reciprocity dynamics under varying mutation rates.
Examination of cooperation thresholds with limited memory.

Main Results:

Intermediate mutation rates facilitate high levels of cooperation.
Cooperation emerges even when benefit-to-cost ratios are just above one.
Mutation-induced diversity stabilizes cooperators and destabilizes defectors.

Conclusions:

Diversity, rather than uniformity, is key to the evolution of cooperation.
Mutation can enable cooperation in scenarios with low benefit-to-cost ratios.
Findings are relevant for understanding cooperation in real-world contexts with limited gains.