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Book Reviews 797 economics profession embraced morality as a In biology, the theory of evolution indeed creates worthy area of research? Are publications on sense where there was none before. morality and economic outcomes getting pub- To say the same about economics and evolu- lished in A-level journals? To answer these ques- tion would of course be too much. Many things tions, I conducted a couple of searches on the in economics make sense and will keep on making distinct words “morality,” “culture,” or “trust.” sense with or without evolution. But since eco- First, I undertook a narrow search using nomics is all about human behavior, and humans JSTOR. I searched the titles and abstracts of have become what they are through mutation and articles between 1970–2012 appearing in the selection, one could imagine that, if there should American Economic Review, Quarterly Journal be a fundamental source for hypotheses concern- of Economics, and Journal of Political Economy. ing how we behave, the only serious candidate is In all, I found 2 hits for “morality,” 17 for “cul- evolution. Of course there is also rationality, but ture,” and 26 for “trust.” My second, broader that is only an intermediate source for hypotheses search relied on all economics and finance jour- since a natural follow-up question would be how nals in ScienceDirect since 1970. The numbers and why evolution would have selected for ratio- were revealing. There were 59 captures on nality, or why it would have selected the (bounded) “morality,” 795 on “culture,” and 657 on “trust.” rationality that we have. It was therefore only a There is a decided structural break around 2008 matter of time that an interest in evolution would (presumably owing to the financial crisis) when arise among economists, just as it would—and the frequency of hits nearly doubles. The Moral has—in psychology, sociology, and anthropology. Foundation of Economic Behavior, I hope, will Samuel Bowles and Herbert Gintis were among help hasten this change in the profession. the first from economics, and their A Cooperative Species: Human Reciprocity and Its Evolution References reflects around ten years of work exploring evolu- Wilson, James Q. 1993. The Moral Sense. New York: tionary explanations of how we got to be the coop- Simon and Schuster, Free Press. erative, reciprocal animal that we are. Janice Boucher Breuer The quest for an evolutionary explanation of University of South Carolina human cooperation of course did not start at the turn of the century; it naturally came right along with Darwin’s great insight. It is only relatively D Microeconomics recently that economists became interested in evolution too. In the 1990s, there was a wave of A Cooperative Species: Human Reciprocity and research in evolutionary game theory, which was Its Evolution. By Samuel Bowles and Herbert mainly focused on disequilibrium dynamics and Gintis. Princeton and Oxford: Princeton how learning could make behavior converge to University Press, 2011. Pp. xii, 262. $35.00. equilibrium play. One of the nice spillovers of ISBN 978–0–691–15125–0. that first wave is that it introduced us to tools JEL 2011–1324 such as the replicator dynamics and to equi- librium refinements such as the evolutionarily Introduction stable strategy, which are also useful for evolu- tionary theory that is not limited to the within In 1973, geneticist and evolutionary biologist generations timescale one typically associates Theodosius Dobzhansky wrote an essay in which with learning models. Thereby it prepared us for he argued against what we now would call intel- a second wave of evolutionary explanations, this ligent design. To underscore his position about time not only of how we update our behavior, how theory and empirical evidence relate, he given what we want and what we value, but also gave the essay the famous title Nothing in Biology how we came to want and value those things in Makes Sense Except in the Light of Evolution. the first place. That of course makes for a fantastically power- The book by Bowles and Gintis reflects their con- ful quote and it has been used a million times. tributions to this second, more interdisciplinary 798 Journal of Economic Literature, Vol. L (September 2012) wave. It draws on journal articles of theirs, departures from random group formation. together and apart, with and without other coau- Because that implies that individuals within thors. These papers are reorganized, rewritten, groups are (somewhat) related, it is natural to and enriched with chapters that provide a back- wonder whether group selection and kin selec- ground. Although the seams and patches are still tion are one and the same thing, or if perhaps somewhat visible, it is very welcome as a guide to, one is subsumed under the other. The answer and overview of, their work. to that question is somewhat involved, but it is safe to say that group selection should come with Keen to Cooperate, Eager to Punish some degree of relatedness, and one of the inter- esting follow up questions is of course whether In the description of the behavior that is or not the conditions for normal, run-of-the-mill to be explained, Bowles and Gintis contrast group selection to explain our levels of coop- the empirical evidence with the tendency, eration are satisfied in humans. Therefore they observed in economists and Americans, to try introduce the reader to the FST , which is a mea- to explain all cooperative behavior as a result sure of relatedness. of self-interest, rightly understood. They con- They then go on to describe how reciproc- vincingly argue that such an explanation would ity features in the repeated games literature in not do justice to the keen eye for cooperation economics. The gist of their discussion is that that humans have, their tendency toward fair- we have been very creative in finding equilibria ness, and their taste for retribution. Of course, in repeated games, squeezing the shadow of the we have a keen eye for our own interests too, future dry in a variety of settings, but that the but sometimes we are simply genuinely happy existence of equilibria is not the same as them to help out and intrinsically eager to punish being likely to be established. The more players free-riders. The obvious next question is then: there are, and the less information players have why? Before going to their own contributions, about past actions, the harder it gets for us to find they first describe the existing, classical expla- equilibria, let alone equilibria that we can expect nations from sociobiology. There is kin selec- are also easily found by a process of mutation and tion theory, which implies that selfish genes can selection. They argue that there is a role to be make altruistic people because interactions may played for norms here. take place between related individuals. If indi- viduals are related, then genes that make their Relatedness and Warfare bearers confer a benefit to the other, at a cost to themselves, can be selected for because of the In the next chapter, they venture the farthest fact that these benefits are conferred, not just from their home ground. They give estimates to an average individual from the population, of measures of relatedness for a number of but to an individual that has an increased prob- hunter–gatherer populations, and conclude from ability of being a carrier of the very same gene. those that, in the absence of other ingredients, Of course, in order for this to work, the donor “ancestral conditions were not favorable for the and the recipient have to be sufficiently related, evolution of group-level cooperation by means given costs and benefits. of reciprocal altruism” (101). The link between A second classic is group selection. The short- estimated FST ’s and reciprocal altruism came a est summary of this process is from Wilson and bit as a surprise to me. For given costs and ben- Wilson (2007), who state that “Selfishness beats efits in a standard simple model, it is clear what altruism within groups. Altruistic groups beat a sufficiently high relatedness for unconditional selfish groups. Everything else is commentary” cooperation to evolve would have been; that is, (345). The balance between those two oppos- given by a famous criterion known as Hamilton’s ing forces—within group selection and between rule. Where the threshold for conditional coop- group selection—determines whether altruism eration lies is not clear. The authors claim that the or selfishness wins. The conditions for group FST ’s are not particularly large, and repetitions not selection to work in favor of altruism involve impressively frequent, but from the book it is not Book Reviews 799 clear at which estimates of F ST ’s and continuation group selection pressure against cooperators. probabilities the conclusion would have been that Norms are also assumed to be a group property, this is, in fact, sufficient for conditional coopera- which is retained if groups fission. Because of tion to readily evolve. But even though this point their effect on within group selection, correlation remains somewhat less sharp, it is only the upbeat between the level of cooperation and the level of to one of the main themes in the book, which the norm builds up over time, and because the loses none of its appeal. The key ingredient that more cooperative groups beat the less coopera- Bowles and Gintis suggest has played a major role tive ones, norms can spread. Norms and behav- in the evolution of human cooperation is, para- ior therefore are coevolving; they play leapfrog, doxically, intergroup warfare. Before they go on the norm making cooperation less costly, and to models of intergroup conflict, they provide us the increased cooperation being what makes the with archaeological and ethnographic evidence of norm spread by winning wars for the groups that mortality due to warfare.