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The nature of human altruism


Some of the most fundamental questions concerning our evolutionary origins, our social relations, and the organization of society are centred around issues of altruism and selfishness. Experimental evidence indicates that human altruism is a powerful force and is unique in the animal world. However, there is much individual heterogeneity and the interaction between altruists and selfish individuals is vital to human cooperation. Depending on the environment, a minority of altruists can force a majority of selfish individuals to cooperate or, conversely, a few egoists can induce a large number of altruists to defect. Current gene-based evolutionary theories cannot explain important patterns of human altruism, pointing towards the importance of both theories of cultural evolution as well as gene–culture co-evolution.

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We gratefully acknowledge support by the Ludwig Boltzmann Institute for the Analysis of Economic Growth, by the Swiss National Science Foundation and by the MacArthur Foundation Network on Economic Environments and the Evolution of Individual Preferences and Social Norms. We thank G. Bornstein, S. Bowles, R. Boyd, M. Brewer, J. Carpenter, S. Gächter, H. Gintis, J. Henrich, K. Hill, M. Milinski, P. Richerson, A. Riedl, K. Sigmund, E. A. Smith, D. S. Wilson and T. Yamagichi for comments on the manuscript, and M. Naef, D. Reding and M. Jörg for their research assistance.

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The authors declare that they have no competing financial interests.

Correspondence to Ernst Fehr.

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Further reading

Figure 1: Altruistic punishment by third parties who are not directly affected by the violation of a fairness norm (based on ref. 27).
Figure 2: The decay of cooperation over time.
Figure 3: Responders' acceptance thresholds in the ultimatum game with and without reputation opportunities.
Figure 4: Simulations of the evolution of cooperation in multi-person prisoners' dilemmas with group conflicts and different degrees of altruistic punishment.


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