Indirect reciprocity provides a narrow margin of efficiency for costly punishment

Department of Value and Decision Science, Tokyo Institute of Technology, Tokyo 152-8552, Japan.
Nature (Impact Factor: 42.35). 02/2009; 457(7225):79-82. DOI: 10.1038/nature07601
Source: PubMed

ABSTRACT Indirect reciprocity is a key mechanism for the evolution of human cooperation. Our behaviour towards other people depends not only on what they have done to us but also on what they have done to others. Indirect reciprocity works through reputation. The standard model of indirect reciprocity offers a binary choice: people can either cooperate or defect. Cooperation implies a cost for the donor and a benefit for the recipient. Defection has no cost and yields no benefit. Currently there is considerable interest in studying the effect of costly (or altruistic) punishment on human behaviour. Punishment implies a cost for the punished person. Costly punishment means that the punisher also pays a cost. It has been suggested that costly punishment between individuals can promote cooperation. Here we study the role of costly punishment in an explicit model of indirect reciprocity. We analyse all social norms, which depend on the action of the donor and the reputation of the recipient. We allow errors in assigning reputation and study gossip as a mechanism for establishing coherence. We characterize all strategies that allow the evolutionary stability of cooperation. Some of those strategies use costly punishment; others do not. We find that punishment strategies typically reduce the average payoff of the population. Consequently, there is only a small parameter region where costly punishment leads to an efficient equilibrium. In most cases the population does better by not using costly punishment. The efficient strategy for indirect reciprocity is to withhold help for defectors rather than punishing them.

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Available from: Yoh Iwasa, Jul 08, 2015
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    • "One point of contention is how punishment compares to rewards and other forms of positive reinforcement. Punishment may not be efficient from the group's perspective (Ohtsuki et al., 2009). Because costly punishment lowers the payoff of both the punisher and punished, in some experiments it yields lower average payoffs for the group (Dreber et al., 2008). "
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    ABSTRACT: Human cooperation is a novel evolutionary puzzle because we cooperate with genetically unrelated individuals in groups that comprise millions of people. Direct reciprocity, especially when considering errors in behavior, has shed light on pairwise cooperation among well-known but genetically unrelated people. Three mechanisms have been identified to explain large-scale cooperation in humans. Cooperation can evolve by indirect reciprocity in groups as long as people can observe each other’s behavior, or can garner honest information via gossip on who cooperates and defects in their interactions. Humans also have a disposition to cooperate and to punish those who do not, even at a cost to oneself, and such costly punishment can sustain cooperation in even larger groups of people who do not know much about each other. Cultural group selection explains the scale of human cooperation, why it is variable, and why norms enforced by sanctions are group-beneficial. Support for these theories has come from laboratory experiments using a variety of behavioral economic games, and from field studies in small-scale societies. Key open questions include understanding what characterizes goodness in indirect reciprocity, why gossip is sufficiently accurate, and why people are motivated to engage in costly punishment.
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    • "In this paper, we adopt the reputation updating rule of indirect reciprocity in [38], i.e., the reputation of relay is updated according to the following rule: "
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    11/2014; DOI:10.1109/TCYB.2014.2366971
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    • "All rights reserved. 2003, 2004; Brandt and Sigmund, 2004, 2005, 2006; Ohtsuki and Iwasa, 2004, 2006, 2007; Takahashi and Mashima, 2006; Suzuki and Akiyama, 2007a,b; Roberts, 2008; Ohtsuki et al., 2009; Sigmund, 2010, 2012; Uchida, 2010; Uchida and Sigmund, 2010; Berger, 2011; Nakamura and Masuda, 2011 "
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    ABSTRACT: Indirect reciprocity is a mechanism for the evolution of cooperation that is relevant for prosocial behavior among humans. Indirect reciprocity means that my behavior towards you also depends on what you have done to others. Indirect reciprocity is associated with the evolution of social intelligence and human language. Most approaches to indirect reciprocity assume obligatory interactions, but here we explore optional interactions. In any one round a game between two players is offered. A cooperator accepts a game unless the reputation of the other player indicates a defector. For a game to take place, both players must accept. In a game between a cooperator and a defector, the reputation of the defector is revealed to all players with probability Q. After a sufficiently large number of rounds the identity of all defectors is known and cooperators are no longer exploited. The crucial condition for evolution of cooperation can be written as hQB>1, where h is the average number of rounds per person and B=(b/c)-1 specifies the benefit-to-cost ratio. We analyze both stochastic and deterministic evolutionary game dynamics. We study two extensions that deal with uncertainty: hesitation and malicious gossip.
    Journal of Theoretical Biology 10/2014; 365. DOI:10.1016/j.jtbi.2014.09.036 · 2.30 Impact Factor