Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Indirect reciprocity can stabilize cooperation without the second-order free rider problem


Models of large-scale human cooperation take two forms. ‘Indirect reciprocity’1 occurs when individuals help others in order to uphold a reputation and so be included in future cooperation. In ‘collective action’2, individuals engage in costly behaviour that benefits the group as a whole. Although the evolution of indirect reciprocity is theoretically plausible3,4,5,6, there is no consensus about how collective action evolves. Evidence suggests that punishing free riders can maintain cooperation7,8,9, but why individuals should engage in costly punishment is unclear. Solutions to this ‘second-order free rider problem’ include meta-punishment10, mutation11, conformism12, signalling13,14,15 and group-selection16,17,18. The threat of exclusion from indirect reciprocity can sustain collective action in the laboratory19. Here, we show that such exclusion is evolutionarily stable, providing an incentive to engage in costly cooperation, while avoiding the second-order free rider problem because punishers can withhold help from free riders without damaging their reputations. However, we also show that such a strategy cannot invade a population in which indirect reciprocity is not linked to collective action, thus leaving unexplained how collective action arises.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Evolutionary dynamics of the Shunner, Defector and Cooperator strategies, plotted in trilinear coordinates.
Figure 2: The threshold degree of assortment (r*, derived in the Supplementary Information) necessary for rare Shunners to invade as a function of the number of mutual aid periods, 1/(1 - w), for two different collective action benefit cost ratios, B/C.
Figure 3: The threshold frequency at which Shunners increase (p*) as a function of the number of mutual aid periods, 1/(1 - w), for different levels of assortment, r.


  1. Alexander, R. D. The Biology of Moral Systems (de Gruyter, New York, 1987)

    Google Scholar 

  2. Olson, M. The Logic of Collective Action: Goods and the Theory of Groups (Harvard Univ. Press, Cambridge, 1971)

    Google Scholar 

  3. Nowak, M. A. & Sigmund, K. The dynamics of indirect reciprocity. J. Theor. Biol. 194, 561–574 (1998)

    CAS  Article  Google Scholar 

  4. Sugden, R. The Economics of Rights, Cooperation and Welfare (Blackwell, Oxford, 1986)

    Google Scholar 

  5. Leimar, O. & Hammerstein, P. Evolution of cooperation through indirect reciprocity. Proc. R. Soc. Lond. B 268, 2495–2501 (2001)

    Article  Google Scholar 

  6. Panchanathan, K. & Boyd, R. A tale of two defectors: the importance of standing for the evolution of reciprocity. J. Theor. Biol. 224, 115–126 (2003)

    MathSciNet  Article  Google Scholar 

  7. Yamagishi, T. The provision of a sanctioning system as a public good. J. Pers. Soc. Psychol. 51, 110–116 (1986)

    Article  Google Scholar 

  8. Ostrom, E. J., Walker, J. & Gardner, R. Covenants with and without a sword: self-governance is possible. Am. Polit. Sci. Rev. 86, 404–417 (1992)

    Article  Google Scholar 

  9. Fehr, E. & Gachter, S. Altruistic punishment in humans. Nature 415, 137–140 (2002)

    ADS  CAS  Article  Google Scholar 

  10. Boyd, R. & Richerson, P. Punishment allows the evolution of cooperation (or anything else) in sizable groups. Ethol. Sociobiol. 13, 171–195 (1992)

    Article  Google Scholar 

  11. Sethi, R. & Somanathan, E. The evolution of social norms in common property resource use. Am. Econ. Rev. 86, 766–788 (1996)

    Google Scholar 

  12. Henrich, J. & Boyd, R. Why people punish defectors—Weak conformist transmission can stabilize costly enforcement of norms in cooperative dilemmas. J. Theor. Biol. 208, 79–89 (2001)

    CAS  Article  Google Scholar 

  13. Smith, E. A. & Bliege Bird, R. L. Turtle hunting and tombstone opening: public generosity as costly signaling. Evol. Hum. Behav. 21, 245–261 (2000)

    CAS  Article  Google Scholar 

  14. Gintis, H., Smith, E. A. & Bowles, S. Costly signaling and cooperation. J. Theor. Biol. 213, 103–119 (2001)

    MathSciNet  CAS  Article  Google Scholar 

  15. Roberts, G. Competitive altruism: from reciprocity to the handicap principle. Proc. R. Soc. Lond. B 265, 427–431 (1998)

    Article  Google Scholar 

  16. Gintis, H. Strong reciprocity and human sociality. J. Theor. Biol. 206, 169–179 (2000)

    CAS  Article  Google Scholar 

  17. Sober, E. & Wilson, D. S. Unto Others: The Evolution and Psychology of Unselfish Behavior (Harvard Univ. Press, Cambridge, 1999)

    Google Scholar 

  18. Boyd, R., Gintis, H., Bowles, S. & Richerson, P. The evolution of altruistic punishment. Proc. Natl Acad. Sci. USA 100, 3531–3535 (2003)

    ADS  CAS  Article  Google Scholar 

  19. Milinski, M., Semmann, D. & Krambeck, H. J. Reputation helps solve the ‘tragedy of the commons’. Nature 415, 424–426 (2002)

    ADS  Article  Google Scholar 

  20. Maynard Smith, J. Evolution and the Theory of Games (Cambridge Univ. Press, Cambridge, 1982)

    Book  Google Scholar 

  21. Axelrod, R. & Hamilton, W. D. The evolution of cooperation. Science 211, 1390–1396 (1981)

    ADS  MathSciNet  CAS  Article  Google Scholar 

  22. Hamilton, W. D. The genetical evolution of social behavior. Parts I, II. J. Theor. Biol. 7, 1–52 (1964)

    CAS  Article  Google Scholar 

  23. Kandori, M., Mailath, G. & Rob, R. Learning, mutation, and long-run equilibria in games. Econometrica 61, 29–56 (1993)

    MathSciNet  Article  Google Scholar 

  24. Young, P. H. The evolution of conventions. Econometrica 61, 57–84 (1993)

    MathSciNet  Article  Google Scholar 

  25. Ellison, G. Learning, local interaction, and coordination. Econometrica 61, 1047–1071 (1993)

    MathSciNet  Article  Google Scholar 

  26. Samuelson, L. Evolutionary Games and Equilibrium Selection (Economic Learning and Social Evolution) (MIT Press, Cambridge, 1997)

    MATH  Google Scholar 

  27. Bowles, S. Microeconomics: Behavior, Institutions, and Evolution (Princeton Univ. Press, Princeton, 2004)

    Google Scholar 

  28. Boyd, R. & Richerson, P. Group selection among alternative evolutionary stable strategies. J. Theor. Biol. 145, 331–342 (1990)

    CAS  Article  Google Scholar 

  29. Soltis, J., Boyd, R. & Richerson, P. Can group-functional behaviors evolve by cultural group selection—An empirical test. Curr. Anthropol. 36, 473–494 (1995)

    Article  Google Scholar 

  30. Boyd, R. & Richerson, P. Group beneficial norms spread rapidly in a structured population. J. Theor. Biol. 215, 287–296 (2002)

    MathSciNet  Article  Google Scholar 

Download references


We thank C. Barrett, S. Bowles, E. Fehr, H. Gintis, J. Henrich, R. Kurzban, S. Naficy, C. Navarrete, D. Penn, J. Silk and the Experimental Biological Anthropology Group for discussions. We especially thank K. Haley for developing the ideas presented in this paper. K.P. was funded by an NSF Graduate Research Fellowship.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Karthik Panchanathan.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Equations

This section provides complete, analytical derivations of the models presented in the main text. This section is broken down into three subsections, representing the three different strategy mixes analysed. (DOC 435 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Panchanathan, K., Boyd, R. Indirect reciprocity can stabilize cooperation without the second-order free rider problem. Nature 432, 499–502 (2004).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing