American Scientist

Cheating Monkeys and Citizen Bees: The Nature of Cooperation in Animals and Humans. Lee Dugatkin. 208 pp. Free Press, 1999. $25.

What do humans have to learn from animals about morality? Not much, it would seem, if, like biologist Lee Dugatkin, one believes moral sensibility to be uniquely human. But in Cheating Monkeys and Citizen Bees, Dugatkin argues that the social behavior of even the lowest animals may teach us about fostering cooperation and moral behavior among humans.

The strength of Dugatkin's book lies in his plain-language explanations of sometimes difficult concepts from evolutionary biology. Moreover, his hope that studying animal behavior may ultimately serve to promote human cooperation imbues his most disquieting subject matter, such as selfish-gene theory, with humanistic relevance. Combined with his tempered use of anecdote and anthropomorphism, this may appeal to readers uneasy with applications of evolutionary thinking to human behavior.

Dugatkin discusses four mechanisms by which natural selection drives cooperation: family dynamics, reciprocal transactions, selfish teamwork and group altruism. In explaining altruism among genetic relatives, he lucidly summarizes kin selection theory and Hamilton's rule, according to which an animal's willingness to compromise its fitness to help another increases with its degree of genetic relatedness to the beneficiary. A clear example can be found in female workers of haplodiploid bee species that forego their reproduction in favor of the queen's; because of their unusual genetics, these workers are more closely related to the queen's daughters than to their own.

The chapter on reciprocal interaction opens with a whirlwind introduction to evolutionary psychology, specifically the theory that humans have evolved a specialized ability to detect cheaters in social exchange. Dugatkin illustrates the conundrum of reciprocity using the Prisoner's Dilemma, in which each of two captured conspirators can either cheat (squeal on their partners) or cooperate (keep silent). In this game, cheating leads to the better outcome from each suspect's standpoint, independent of the other's behavior. So when will cooperation arise? The short answer is when each partner anticipates having a large, unknown number of future interactions with the other. In such repeated interactions, the best strategy turns out to be tit for tat, which mimics the partner's choice in the previous round in eye-for-an-eye fashion but holds no grudges beyond one round.

With this theoretical foundation in place, Dugatkin provides examples of tit-for-tat–style cooperation among unrelated animals. For instance, impala perform reciprocal grooming, alternating turns frequently to discourage freeloading, whereas vampire bats share blood meals only with roostmates that have previously shared with them. Sometimes reciprocal altruism occurs on a time scale so short that the exchange is essentially instantaneous. Such by-product mutualism usually arises in challenging environments. For example, lions typically hunt cooperatively for large prey but alone for small fry.

These clear accounts of the logic behind animal interaction contrast with Dugatkin's sometimes exasperatingly aimless musings on human morality. For instance, his discussion of Pascal's wager about leading a Christian life and such nonquestions as the "reason for people like the late Mother Teresa" are among several points at which the book loses focus. Perhaps this is Dugatkin vying for popular appeal, but he is better off sticking to biology.

The fourth path to cooperation is group selection. Group selection theory attempts to explain animals' sometimes astonishing readiness to imperil themselves in ways that benefit their group. Dugatkin wisely avoids the contentious issues this theory raises and instead focuses on compelling examples, including one from his research on predator inspection. In Trinidadian guppies, a few brave souls perform the dangerous task of approaching predators to gather information about, for instance, how hungry they are. The inspectors then share the information with noninspectors. According to Dugatkin, such cooperation can only be explained at the group level: Groups with inspectors must fare better than those without, although individuals reduce their fitness by inspecting.

Dividing the book into four parts works rhetorically, despite the fact that the various types of cooperation are actually entwined. Only in this chapter does one notice tension between them. Specifically, Dugatkin claims here that cooperators will always lose out to cheaters within a group, and that cooperation pays only when competition is fiercer between groups than within them, without noting that this argument seems to undermine his earlier accounts of kin selection and reciprocal altruism.

In the book's weakest passages, Dugatkin attempts to reconcile his evolutionary analysis with human morality. He worries that popularizations of sociobiology engender the "mistaken impression that feelings like sympathy [and] guilt . . . are really just natural selection manifesting itself and should circumstances change, natural selection may simply favor the converse emotions" (author's emphasis), an "unacceptable" possibility for people (evidently including himself) who believe in "absolute right and wrong." Although this conclusion may indeed be unacceptable, even mistaken, the book provides no basis for rejecting it.

Dugatkin periodically suggests ways in which the four primeval paths to cooperation could be transformed into tools for social engineering. Although he emphasizes the preliminary nature of his proposals and hastens to identify their pitfalls, many of them (for instance, to encourage cooperative behavior in neighborhoods via kin selection by offering financial incentives for people to settle near family members) come off as clumsy and naive.

The types of cooperation we see in nature ultimately stem from competition, whether among genes, individuals, families or groups. Animals help some conspecifics as opposed to others, which paves the way for all kinds of socially undesirable competition. Acknowledging this nasty side effect in a passage on highly cooperative, insular human groups, Dugatkin wonders if it could be avoided by encouraging individuals to belong to multiple, overlapping groups, thus keeping them from identifying too much with any single one.

This seems a faint hope for a book that sets out to help us structure our social world for the better. It is an admittedly tall order, but the result is still disappointing given that this ambition most clearly distinguishes the book from those on similar topics recently published, such as Matt Ridley's literary Origins of Virtue and Elliott Sober and David Sloan Wilson's scholarly Unto Others.

Nevertheless, Cheating Monkeys and Citizen Bees provides a particularly accessible introduction to evolutionary biological thinking and animal social behavior and at least has the gumption to point out a largely untapped animal model for improving human life.