Review of Christopher Boehm, Moral Origins: The Evolution of Virtue, Altruism, and Shame (Basic Books, 2012)
Humanism asserts that human beings are naturally capable of caring about others and taking action to help others, even those who are not like themselves. One only has to notice the worldwide response after Typhoon Haiyan hit the Philippines to be convinced of the truth of that assertion. But despite humanists’ celebration of Charles Darwin for discovering the natural, rather than supernatural, origin of humans and all other species of living things, the exponents of Darwin’s theory of natural selection have had a hard time explaining why human beings are so humane.
Evolutionary theory explains both the biological and cultural characteristics of humans as contributing to their “fitness,” a technical term derived from Herbert Spencer’s concise statement of the theory of natural selection as “survival of the fittest.” Of course one’s own survival is not enough. Reproduction is also essential. Fitness is mathematically defined as the number of surviving offspring an individual has. The children of the fittest parents will be more numerous in the next generation than those of the least fit. If offspring share the biological and cultural characteristics of their parents, the characteristics that contribute to fitness will be increasingly represented in the population, and those that detract from fitness will eventually die out.
On this basis, the theory predicts that humans should have evolved to care only about their own biological offspring and to act only to help them. Of course this is largely true, but it is not the whole story, and evolutionists have been struggling to explain the rest of the story for the past half century. The most popular explanation during that period has been a genetic one, based on the notion of “inclusive fitness.” Genetic fitness can be defined as the multiplication of the individual’s genes in the population. Each parent contributes half of the genes of each of their offspring. But on average, each individual, parent or not, also shares one-half of their genes with each of their siblings and one-fourth of their genes with each nephew or niece. Therefore, a person can increase her inclusive fitness or multiply her genes by aiding the survival not only of her own children but also that of her brothers and sisters and of their children—thus practicing what evolutionists call nepotism or “kin selection.”
This provides a clear explanation of the evolution of the human family as a biological, cultural and social institution. Humans who were genetically capable of loving their family members were more likely than unloving humans to multiply their genes by aiding each other’s survival. In addition, human groups whose cultural and social beliefs and practices reinforced cooperation and loyalty within their family units quickly out-populated groups that did not.
But how can evolutionary theory explain the fact that humans always live in groups larger than the family? Part of the reason for people to form a group is to defend a shared territory, or more precisely, a set of resources that they depend on for survival. Humans have inherited this trait from their common ancestor with chimpanzees and bonobos, who have frequently been observed fighting with neighboring groups over territory. But members of a human group do not only subsist side by side sharing the same natural resources, as do the members of each group of chimps and bonobos. Humans also share food within the group in a systematic, institutionalized way. Even the arch-capitalist nation of the United States does this, to the chagrin of the Tea Party, in the form of our SNAP program, or food stamps.
One recent evolutionary explanation for human sharing within groups is called multilevel selection theory. At one level the families who most effectively promote the survival and reproduction of their own members out-populate the other families within the group by the process of “kin selection.” At the next level the groups who most effectively promote the survival and reproduction of all of the families within them out-populate other groups by the process of “group selection.”
While not endorsing group selection over competing evolutionary theories, in his book Moral Origins: The Evolution of Virtue, Altruism, and Shame, Christopher Boehm presents a new explanation for human morality, and more specifically for how and why human groups share food and other resources. His conclusions are grounded in a lifetime of observation of great apes and analysis of the ethnographies of human groups. The most innovative and daring aspect of his approach is his emphasis on the genetic effects of the social control of “free riders.”
In evolutionary theory, and in its sibling, economic theory, a free rider is an individual who receives food or other goods from the members of his group but does not give anything to them in return. Typically these are thought of as simply unproductive beggars. But Boehm insists that the most important free riders are the thieves and bullies who don’t appeal to other people’s generosity, but instead use force, threats, and coercion to take what others have produced or gathered.
In his years of observing chimp and bonobo groups, Boehm focused on the alpha males, the dominant individuals, the bullies, who by their strength and aggressiveness took food, and perhaps more importantly, sexual opportunities, from their fellows. And he was impressed by the occasional incidents in which the other males in a chimpanzee group ganged up on a particularly oppressive dominant male and threw him out of the group, at least temporarily, or even killed him. (Among the bonobos the females were more likely to do this against a dominant female!) Boehm sees this as the beginning of social control, of the enforcement of constraints by the majority on the free riders within the group.
Killing or exiling the oppressive dominant individual eliminates his or her future chances of reproduction and decisively reduces his or her fitness. But humans have evolved the capacity to restrain their aggressive impulses in order to avoid such punishment from within the group. How this happened, Boehm can only speculate, but his logic is that the individuals whose genes enabled them to behave according to the moral rules of the group, or to have enough compassion for their fellows not to mistreat them, or both, had their fitness increased when social control was strong enough to eliminate the worst thieves and bullies, who did not have those genes for self-control. The capacity for morality spread within the group with each generation, although bullies and psychopaths did not disappear.
The moral code of sharing within the group, which is found in every religion, and of course in humanism as well, goes beyond the suppression of bullies to require everyone to contribute to the good of others, to the best of their ability. Boehm hypothesizes that it emerged when early humans began hunting large animals as a major part of their subsistence strategy. (Our pre-human ancestors seem to have been largely scavengers.) Traditional human nomadic hunting groups surviving into modern times all had strict rules for dividing the meat from large animals they killed more or less equally among all the members of the group. The rules came into play when a human hunter succeeded in killing an animal larger than what his own family could eat before it spoiled. The sustainable solution was to share all the meat from large animals with everyone else in the group, even if some hunters were more often successful than others. Doing this required the hunters to have the capacity for self-restraint and sympathy with the less fortunate members of the group, as well as the capacity to learn and to follow the particular rules of the group. No group of humans whose members lacked these moral capacities could have survived in the harsh and changeable climate of the Pleistocene era when humans evolved. This was group selection at its most extreme.
The question that began this review remains unanswered. Why do humans take pity on others who are not members of their group, much less of their family? Boehm’s suggested explanation for this is what he calls a “slippage model,” in which the feelings of compassion that first evolved in the family context to promote kin selection and inclusive fitness were strong enough to extend not only to companions in the group, but also to persons encountered outside the group who were in real need. Moral ideologies can appeal to kinship feelings, he notes, by using terms of kinship beyond the real kin group, such as “brotherhood” and “sisterhood.” I would add that one of the strongest foundations for my own humanism is the understanding that all humans are indeed kin, and perhaps even descended from the same mother.
(A shortened version of this post has been submitted to The Humanist magazine.