American Scientist

The Altruism Equation: Seven Scientists Search for the Origins of Goodness. Lee Alan Dugatkin. xiv + 188 pp. Princeton University Press, 2006. $24.95.

Primates and Philosophers: How Morality Evolved. Frans de Waal. xx + 209 pp. Princeton University Press, 2006. $22.95.

The Evolution of Morality. Richard Joyce. xii + 271 pp. MIT Press, 2006. $32.

A dangerous idea is like any other peril: One's first impulse on confronting it is to fight or run away. This simple observation goes a long way toward explaining the turbulent history of evolutionary theory, with its threatening implications for cherished notions such as religion, morality and human potential. Some of that turbulent history, and a variety of views on the relation between evolution and morality, can be sampled in three recent books: In The Altruism Equation, biologist Lee Dugatkin gives biographical sketches of seven major historical figures who took an interest in the importance of blood kinship in shaping social behavior. In Primates and Philosophers, primatologist Frans de Waal and a group of philosophers and social theorists (Robert Wright, Christine M. Korsgaard, Philip Kitcher and Peter Singer) have a dialogue about the roots of morality in nonhuman species. And in The Evolution of Morality, philosopher Richard Joyce provides a rigorous, if preliminary, overview of what evolutionary theory means for moral philosophy.

It is not easy to reconcile morality and altruism with evolution. Natural selection appears to favor individuals who further themselves at the expense of others, whereas morality is inherently about helping others or benefiting society as a whole. Darwin wrestled with this problem and came up with two provisional explanations. The first grew out of the simple observation that family members tend to share the same traits. (This is what enables animal breeders to sacrifice some individuals but still retain their traits by allowing their relatives to breed.) So perhaps some individuals (honeybee workers, for example) evolve to sacrifice their own lives so that their relatives (in the case of honeybees, the queen) can breed. Darwin's second explanation was that groups of altruists will be better at rounding up food, fending off predators and so forth, giving them a decisive advantage over groups of more selfish individuals. Darwin invoked group selection to explain the evolution of moral behavior in humans, envisioning the groups as entire tribes.

Dugatkin traces the history of these ideas from Darwin to the present, culminating with a discussion of theories that express the conditions for the evolution of altruism in mathematical terms. Thomas Huxley, "Darwin's bulldog," regarded nature as primarily "red in tooth and claw." In 1888, Huxley wrote that "beyond the limited and temporary relations of the family, the Hobbesian war of each against all was the normal state of existence." He believed that human morality is not something that evolved—it requires rebelling against our animal nature. Huxley's contemporary Petr Kropotkin, the Russian prince and anarchist, objected; he thought that Darwin and Huxley vastly underestimated the importance of mutual aid in all kinds of groups.

From the 1920s through the 1940s, University of Chicago biologist W. C. Alee tried, as Kropotkin had, to elevate cooperation to a grand principle of nature. By the middle of the 20th century, evolutionary theory had been placed on a mathematical foundation by J. B. S. Haldane, Ronald Fisher and Sewall Wright, but these men only touched on the problem of altruism, perhaps because they were not field biologists and lacked direct observational experience.

According to Dugatkin, the "altruism equation" was not fully derived until the late William D. Hamilton and George R. Price developed their theories. Hamilton's rule, set forth in 1963, states that natural selection favors a gene that codes for altruism over one that does not whenever r (the coefficient of genetic relatedness between an altruist and a recipient of altruism) multiplied by b (the benefit that the recipient obtains) is greater than c (the cost paid by the altruist). So in this model the cost is balanced by benefits to close genealogical relatives of the altruist.

Dugatkin's biographical sketches of these men are entertaining and insightful. Historians of science will want more detail, but there is little doubt that efforts to explain altruism and morality in formal scientific terms are heavily influenced by the cultures and personal histories of their proponents. Scientific progress does get made, but it is a messy process, like the making of laws and sausages. The more we know about the social, cultural and individual contexts, the better.

Unfortunately, Dugatkin's account is marred by a bias of his own. He seems to be fixated on altruism among "blood relatives" to the exclusion of other kinds of mutual aid. This leads him to misrepresent both history and contemporary sociobiology. By my own estimation, altruism became narrowly associated with genealogical relatedness during a single historical period, starting in the 1960s with Hamilton's first papers and John Maynard Smith's interpretation. Price's work in the 1970s is important in part because it broadened the interpretation of r to include any positive genetic (or even phenotypic) correlation among members of a group—as Hamilton stressed in his 1975 reformulation of inclusive fitness theory in terms of the Price equation.

Moreover, the thrust of modern research has been to show that high degrees of cooperation can evolve with low values of r (even r=0), based on mechanisms such as mutual policing. The ultra-social behavior of social insects, for example, is no longer thought to require ultrahigh values of genealogical relatedness. Instead, the rb in Hamilton's equation can be interpreted as the measure of how much the personal reproduction of an average carrier of a gene for altruism is enhanced by help from others, whether they are relatives or not. In recent reviews of kin-selection theory, associating r with genealogical relatedness is often characterized as a fallacy, so it is puzzling that Dugatkin, who is undoubtedly familiar with the literature, would emphasize this original definition so strongly.

In the lead essay in Primates and Philosophers, Frans de Waal provides a historical sketch of his own (beginning with Thomas Hobbes and Thomas Huxley) and proceeds to show how elements of morality such as empathy, sympathy, community concern and a sense of fairness also exist in our closest primate relatives. De Waal describes his research as an attack on "veneer theory," which imagines human morality to be a thin veneer overlaying a selfish animal nature.

Robert Wright (who says he is one of those whom de Waal labels a veneer theorist) argues in his response that behavioral similarities between humans and other primates conceal important psychological differences. Ape behavior is more likely to be guided by emotions, he believes, whereas seemingly similar human behavior is more likely to be guided by conscious strategizing. Christine Korsgaard largely agrees with Wright. As she puts it,

an animal that can entertain his purposes before his mind, and perhaps even entertain thoughts about how to achieve those purposes, is exerting a greater degree of conscious control over his own movements than, say, the spider [going toward a moth caught in her web], and is therefore in a deeper sense an agent.

For Wright and Korsgaard, it is agency, rather than emotionally driven behavior, that defines human morality.

Philip Kitcher regards de Waal's "sledgehammer" approach to veneer theory as unhelpful, because it fails to distinguish among varieties of psychological altruism:

Until we have a clearer view of the specific kinds of psychological altruism chimpanzees (and other nonhuman primates) display, and until we know what kinds are relevant to morality, it's premature to claim that human morality is a "direct outgrowth" of tendencies these animals share.

Kitcher, like Wright and Korsgaard, wants to strike a balance between continuity and uniqueness:

I suspect that between us and our most recent common ancestor with the chimps there have been some very important evolutionary steps: the emergence of a capacity for normative guidance and self-control, the ability to speak and to discuss potential moral resources with one another, and about fifty thousand years (at least) of important cultural evolution.

Peter Singer points out that ape morality is invariably oriented toward benefiting one's own group, whereas human morality is at least sometimes impartial, treating all groups equally:

[T]he Chinese philosopher Mozi, appalled at the damage caused by war, asked: "What is the way of universal love and mutual benefit?" and answered his own question: "It is to regard other people's countries as one's own." Yet, as de Waal points out, the practice of this more impartial morality is "fragile." Doesn't this conception come very close to saying that the impartial element of morality is a veneer, laid over our evolved nature?

Primates and Philosophershas the spontaneity of a good conversation but also some of the redundancy and disorganization. The Evolution of Moralityis a more sustained effort to explore the implications of evolutionary theory for moral philosophy. Author Richard Joyce begins by reviewing the standard theories for the evolution of altruism, before making his main point—which is that altruism fails to capture the essence of human morality, no matter how it evolved:

We can easily imagine a community of people all of whom have the same desires: They all want to live in peace and harmony, and violence is unheard of. Everywhere you look there are friendly, loving people, oozing prosocial emotions. However, there is no reason to think that there is a moral judgment in sight. Those imaginary beings have inhibitions against killing, stealing, etc. They wouldn't dream of doing such things; they just don't want to do them. But we need not credit them with a conception of prohibition: the idea that one shouldn't kill or steal because to do so is wrong. And moral judgments require, among other things, the capacity to understand prohibitions.

In Joyce's view, the kind of altruism emphasized by Dugatkin is especially inadequate to explain human morality. After all, nepotism is just one step away from individual selfishness in a society that includes nonrelatives.

For Joyce, the evolutionary puzzle is to explain the human capacity to make, enforce and abide by moral judgments. Yet the answer he arrives at is much the same as for the evolution of altruism envisioned by Darwin so long ago: Groups of individuals who possess these capacities survive and reproduce better than groups that don't.

Joyce's sustained inquiry includes many interesting observations and asides. The Evolution of Morality is the most demanding of the three books discussed here but is also the most rewarding for those willing to make the effort.

One of the most important distinctions in evolutionary theory is between proximate and ultimate causation. The concepts are seldom mentioned by name in the three books but nevertheless can be used to summarize their contents. There is something about morality that is inherently behavioral and other-oriented. As Joyce puts it, "Morality seems to be designed to serve society." On the other hand, morality cannot be defined exclusively at the behavioral level. The proximate mechanism also matters, although agreement about the particular magic ingredient is notoriously difficult to achieve.

This is exactly what we should expect from an evolutionary perspective. Group-oriented behaviors have evolved in many species, from microbes on up. Even within our own species, the 50,000 years of cultural evolution emphasized by Kitcher could have produced very different ways of achieving cooperation in different cultures. A given element of morality (such as internalized guilt) might be crucial in some cultures and peripheral or even absent in others. This point might be especially difficult to grasp for those who base their ideas about morality on their own intuition. When a given phenotype can evolve by many different proximate mechanisms, it is typical for evolutionists to regard any particular mechanism as secondary in importance; if one is not available, another will take its place. The one-to-many relationship inherent in the ultimate/proximate distinction argues against basing definitions of morality on any particular proximate mechanism.