title: Human cooperation based on punishment reputation.
abstract: The threat of punishment usually promotes cooperation. However, punishing itself is costly, rare in nonhuman animals, and humans who punish often finish with low payoffs in economic experiments. The evolution of punishment has therefore been unclear. Recent theoretical developments suggest that punishment has evolved in the context of reputation games. We tested this idea in a simple helping game with observers and with punishment and punishment reputation (experimentally controlling for other possible reputational effects). We show that punishers fully compensate their costs as they receive help more often. The more likely defection is punished within a group, the higher the level of within-group cooperation. These beneficial effects perish if the punishment reputation is removed. We conclude that reputation is key to the evolution of punishment.
authors.affiliation: Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland.
authors.forename: Miguel
authors.initials: M
authors.lastname: dos Santos
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Rankin
authors.forename: Claus
authors.initials: C
authors.lastname: Wedekind
mesh_terms: D005075:Biological Evolution; D003299:Cooperative Behavior; D005717:Games, Experimental; D006801:Humans; D008960:Models, Psychological; D011678:Punishment
keywords: Experimental game theory; indirect reciprocity; punishment