Paul Seabright is the first to clearly identify a major puzzle about human social evolution: the expansion of cooperation in the more complex societies of the Holocene. Identifying that problem is a major achievement, but in this paper I give a somewhat different account of the nature of the problem and a somewhat different account of the social world of Pleistocene foragers. So, we agree that there is a problem, but not on its nature or solution.

The revised edition of Paul Seabright’s The Company of Strangers is critically reviewed. Seabright aims to help non-economists participating in the cross-disciplinary study of the evolution of human sociality appreciate the potential value that can be added by economists. Though the book includes nicely constructed and vivid essays on a range of economic topics, in its main ambition it largely falls short. The most serious problem is endorsement of the so-called strong reciprocity hypothesis that has been promoted by several prominent (...) economists, but does not pass muster with biologists. (shrink)

Strong Reciprocity theorists claim that cooperation in social dilemma games can be sustained by costly punishment mechanisms that eliminate incentives to free ride, even in one-shot and finitely repeated games. There is little doubt that costly punishment raises cooperation in laboratory conditions. Its efficacy in the field however is controversial. I distinguish two interpretations of experimental results, and show that the wide interpretation endorsed by Strong Reciprocity theorists is unsupported by ethnographic evidence on decentralised punishment and by historical evidence on (...) common pool institutions. The institutions that spontaneously evolve to solve dilemmas of cooperation typically exploit low-cost mechanisms, turning finite games into indefinitely repeated ones and eliminating the cost of sanctioning. (shrink)

The disagreement between Binmore and the “behaviouralists” concerns mainly the kind of reciprocity mechanisms that sustain cooperation in and out of the experimental laboratory. Although Binmore’s scepticism concerning Strong Reciprocity is justified, his case for Weak Reciprocity and the long-run convergence to Nash equilibria is unsupported by laboratory evidence. Part of the reason is that laboratory evidence alone cannot solve the reciprocity controversy, and researchers should pay more attention to field data. As an example, I briefly illustrate a historical case (...) suggesting that the institutions that foster cooperation in the real world rely on Weak Reciprocity mechanisms such as those that feature prominently in Binmore’s story. (shrink)

The standard theories of cooperation in humans, which depend on repeated interaction and reputation effects among self-regarding agents, are inadequate. Strong reciprocity, a predisposition to participate in costly cooperation and the punishment, fosters cooperation where self-regarding behaviors fail. The effectiveness of socially coordinated punishment depends on individual motivations to participate, which are based on strong reciprocity motives. The relative infrequency of high-cost punishment is a result of the ubiquity of strong reciprocity, not its absence.

It is central to standard economic theory that people act on their interests. People are interested in a variety of things, so a range of values should influence market behavior. When engaged in commerce, however, people generally act for personal gain; the influence of other values usually just disappears in the marketplace. What is missing from the standard account is that people often act on proper subsets of their interests. Economics can, however, be extended to capture this insight. Key Words: (...) economic theory • attention • self-interest • social responsibility • discrimination. (shrink)

Experimental studies on punishment have sometimes been over-interpreted not only for the reasons Guala lists, but also because of a frequent conflation of proximate and ultimate explanatory levels that Guala's review perpetuates. Moreover, for future analyses we may need a clearer classification of different kinds of punishment.