Group Cooperation without Group Selection: Modest Punishment Can Recruit Much Cooperation

• Max M. Krasnow ,

  Contributed equally to this work with: Max M. Krasnow, Andrew W. Delton

  * E-mail: krasnow@fas.harvard.edu

  Affiliation Department of Psychology, Harvard University, Cambridge, Massachusetts, United States of America

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• Andrew W. Delton ,

  Contributed equally to this work with: Max M. Krasnow, Andrew W. Delton

  Affiliation Department of Political Science, College of Business, Center for Behavioral Political Economy, Stony Brook University, Stony Brook, New York, United States of America

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• Leda Cosmides,

  Affiliations Center for Evolutionary Psychology, University of California Santa Barbara, Santa Barbara, California, United States of America, Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, California, United States of America

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• John Tooby

  Affiliations Center for Evolutionary Psychology, University of California Santa Barbara, Santa Barbara, California, United States of America, Department of Anthropology, University of California Santa Barbara, Santa Barbara, California, United States of America

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