The People Who Evolved Our Genes for Us: Christopher Boehm on Moral Origins – Part 3 of A Crash Course in Multilevel Selection Theory

Start with Part 1.
In a 1969 account of her time in Labrador studying the culture of the Montagnais-Naskapi people, anthropologist Eleanor Leacock describes how a man named Thomas, who was serving as her guide and informant, responded to two men they encountered while far from home on a hunting trip. The men, whom Thomas recognized but didn’t know very well, were on the brink of starvation. Even though it meant ending the hunting trip early and hence bringing back fewer furs to trade, Thomas gave the hungry men all the flour and lard he was carrying. Leacock figured that Thomas must have felt at least somewhat resentful for having to cut short his trip and that he was perhaps anticipating some return favor from the men in the future. But Thomas didn’t seem the least bit reluctant to help or frustrated by the setback. Leacock kept pressing him for an explanation until he got annoyed with her probing. She writes,
Eleanor Leacock
This was one of the very rare times Thomas lost patience with me, and he said with deep, if suppressed anger, “suppose now, not to give them flour, lard—just dead inside.” More revealing than the incident itself were the finality of his tone and the inference of my utter inhumanity in raising questions about his action. (Quoted in Boehm 219)
The phrase “just dead inside” expresses how deeply internalized the ethic of sympathetic giving is for people like Thomas who live in cultures more similar to those our earliest human ancestors created at the time, around 45,000 years ago, when they began leaving evidence of engaging in all the unique behaviors that are the hallmarks of our species. The Montagnais-Naskapi don’t qualify as an example of what anthropologist Christopher Boehm labels Late Pleistocene Appropriate, or LPA, cultures because they had been involved in fur trading with people from industrialized communities going back long before their culture was first studied by ethnographers. But Boehm includes Leacock’s description in his book Moral Origins: The Evolution of Virtue, Altruism, and Shame because he believes Thomas’s behavior is in fact typical of nomadic foragers and because, infelicitously for his research, standard ethnographies seldom cover encounters like the one Thomas had with those hungry acquaintances of his.
            In our modern industrialized civilization, people donate blood, volunteer to fight in wars, sign over percentages of their income to churches, and pay to keep organizations like Doctors without Borders and Human Rights Watch in operation even though the people they help live in far-off countries most of us will never visit. One approach to explaining how this type of extra-familial generosity could have evolved is to suggest people who live in advanced societies like ours are, in an important sense, not in their natural habitat. Among evolutionary psychologists, it has long been assumed that in humans’ ancestral environments, most of the people individuals encountered would either be close kin who carried many genes in common, or at the very least members of a moderately stable group they could count on running into again, at which time they would be disposed to repay any favors. Once you take kin selection and reciprocal altruism into account, the consensus held, there was not much left to explain. Whatever small acts of kindness that weren’t directed toward kin or done with an expectation of repayment were, in such small groups, probably performed for the sake of impressing all the witnesses and thus improving the social status of the performer. As the biologist Michael Ghiselin once famously put it, “Scratch an altruist and watch a hypocrite bleed.” But this conception of what evolutionary psychologists call the Environment of Evolutionary Adaptedness, or EEA, never sat right with Boehm.
Christopher Boehm
            One problem with the standard selfish gene scenario that has just recently come to light is that modern hunter-gatherers, no matter where in the world they live, tend to form bands made up of high percentages of non-related or distantly related individuals. In an article published in Science in March of 2011, anthropologist Kim Hill and his colleagues report the findings of their analysis of thirty-two hunter-gatherer societies. The main conclusion of the study is that the members of most bands are not closely enough related for kin selection to sufficiently account for the high levels of cooperation ethnographers routinely observe. Assuming present-day forager societies are representative of the types of groups our Late Pleistocene ancestors lived in, we can rule out kin selection as a likely explanation for altruism of the sort displayed by Thomas or by modern philanthropists in complex civilizations. Boehm offers us a different scenario, one that relies on hypotheses derived from ethological studies of apes and archeological records of our human prehistory as much as on any abstract mathematical accounting of the supposed genetic payoffs of behaviors.
            In three cave paintings discovered in Spain that probably date to the dawn of the Holocene epoch around 12,000 years ago, groups of men are depicted with what appear to be bows lifted above their heads in celebration while another man lay dead nearby with one arrow from each of them sticking out of his body. We can only speculate about what these images might have meant to the people who created them, but Boehm points out that all extant nomadic foraging peoples, no matter what part of the world they live in, are periodically forced to reenact dramas that resonate uncannily well with these scenes portrayed in ancient cave art. “Given enough time,” he writes, “any band society is likely to experience a problem with a homicide-prone unbalanced individual. And predictably band members will have to solve the problem by means of execution” (253). One of the more gruesome accounts of such an incident he cites comes from Richard Lee’s ethnography of !Kung Bushmen. After a man named /Twi had killed two men, Lee writes, “A number of people decided that he must be killed.” According to Lee’s informant, a man named =Toma (the symbols before the names represent clicks), the first attempt to kill /Twi was botched, allowing him to return to his hut, where a few people tried to help him. But he ended up becoming so enraged that he grabbed a spear and stabbed a woman in the face with it. When the woman’s husband came to her aid, /Twi shot him with a poisoned arrow, killing him and bringing his total body count to four. =Toma continues the story,
Now everyone took cover, and others shot at /Twi, and no one came to his aid because all those people had decided he had to die. But he still chased after some, firing arrows, but he didn’t hit any more…Then they all fired on him with poisoned arrows till he looked like a porcupine. Then he lay flat. All approached him, men and women, and stabbed his body with spears even after he was dead. (261-2)
The two most important elements of this episode for Boehm are the fact that the death sentence was arrived at through a partial group consensus which ended up being unanimous, and that it was carried out with weapons that had originally been developed for hunting. But this particular case of collectively enacted capital punishment was odd not just in how clumsy it was. Boehm writes,
!Kung Hunters
In this one uniquely detailed description of what seems to begin as a delegated execution and eventually becomes a fully communal killing, things are so chaotic that it’s easy to understand why with hunter-gatherers the usual mode of execution is to efficiently delegate a kinsman to quickly kill the deviant by ambush. (261)
The prevailing wisdom among evolutionary psychologists has long been that any appearance of group-level adaptation, like the collective killing of a dangerous group member, must be an illusory outcome caused by selection at the level of individuals or families. As Steven Pinker explains, “If a person has innate traits that encourage him to contribute to the group’s welfare and as a result contribute to his own welfare, group selection is unnecessary; individual selection in the context of group living is adequate.” To demonstrate that some trait or behavior humans reliably engage in really is for the sake of the group as opposed to the individual engaging in it, there would have to be some conflict between the two motives—serving the group would have to entail incurring some kind of cost for the individual. Pinker explains,
It’s only when humans display traits that are disadvantageous to themselves while benefiting their group that group selection might have something to add. And this brings us to the familiar problem which led most evolutionary biologists to reject the idea of group selection in the 1960s. Except in the theoretically possible but empirically unlikely circumstance in which groups bud off new groups faster than their members have babies, any genetic tendency to risk life and limb that results in a net decrease in individual inclusive fitness will be relentlessly selected against. A new mutation with this effect would not come to predominate in the population, and even if it did, it would be driven out by any immigrant or mutant that favored itself at the expense of the group.
The ever-present potential for cooperative or altruistic group norms to be subverted by selfish individuals keen on exploitation is known in game theory as the free rider problem. To see how strong selfish individuals can lord over groups of their conspecifics we can look to the hierarchically organized bands great apes naturally form.
            In groups of chimpanzees, for instance, an alpha male gets to eat his fill of the most nutritious food, even going so far at times as seizing meat from the subordinates who hunted it down. The alpha chimp also works to secure, as best he can, sole access to reproductively receptive females. For a hierarchical species like this, status is a winner-take-all competition, and so genes for dominance and cutthroat aggression proliferate. Subordinates tolerate being bullied because they know the more powerful alpha will probably kill them if they try to stand up for themselves. If instead of mounting some ill-fated resistance, however, they simply bide their time, they may eventually grow strong enough to more effectively challenge for the top position. Meanwhile, they can also try to sneak off with females to couple behind the alpha’s back. Boehm suggests that two competing motives keep hierarchies like this in place: one is a strong desire for dominance and the other is a penchant for fear-based submission. What this means is that subordinates only ever submit ambivalently. They even have a recognizable vocalization, which Boehm transcribes as the “waa,” that they use to signal their discontent. In his 1999 book Hierarchy in the Forest: The Evolution of Egalitarian Behavior, Boehm explains,
When an alpha male begins to display and a subordinate goes screaming up a tree, we may interpret this as a submissive act of fear; but when that same subordinate begins to waa as the display continues, it is an open, hostile expression of insubordination. (167)
Since the distant ancestor humans shared in common with chimpanzees likely felt this same ambivalence toward alphas, Boehm theorizes that it served as a preadaptation for the type of treatment modern human bullies can count on in every society of nomadic foragers anthropologists have studied. “I believe,” he writes, “that a similar emotional and behavioral orientation underlies the human moral community’s labeling of domination behaviors as deviant” (167).
            Boehm has found accounts of subordinate chimpanzees, bonobos, and even gorillas banding together with one or more partner to take on an excessively domineering alpha—though there was only one case in which this happened with gorillas and the animals in question lived in captivity. But humans are much better at this type of coalition building. Two of the most crucial developments in our own lineage that lead to the differences in social organization between ourselves and the other apes were likely to have been an increased capacity for coordinated hunting and the invention of weapons designed to kill big game. As Boehm explains,
Weapons made possible not only killing at a distance, but far more effective threat behavior; brandishing a projectile could turn into an instant lethal attack with relatively little immediate risk to the attacker. (175)
Deadly weapons fundamentally altered the dynamic between lone would-be bullies and those they might try to dominate. As Boehm points out, “after weapons arrived, the camp bully became far more vulnerable” (177). With the advent of greater coalition-building skills and the invention of tools for efficient killing, the opportunities for an individual to achieve alpha status quickly vanished.

            It’s dangerous to assume that any one group of modern people provides the key to understanding our Pleistocene ancestors, but when every group living with similar types of technology and subsistence methods as those ancestors follows a similar pattern it’s much more suggestive. “A distinctively egalitarian political style,” Boehm writes, “is highly predictable wherever people live in small, locally autonomous social and economic groups” (35-6). This egalitarianism must be vigilantly guarded because “A potential bully always seems to be waiting in the wings” (68). Boehm explains what he believes is the underlying motivation,
Even though individuals may be attracted personally to a dominant role, they make a common pact which says that each main political actor will give up his modest chances of becoming alpha in order to be certain that no one will ever be alpha over him. (105)
The methods used to prevent powerful or influential individuals from acquiring too much control include such collective behaviors as gossiping, ostracism, banishment, and even, in extreme cases, execution. “In egalitarian hierarchies the pyramid of power is turned upside down,” Boehm explains, “with a politically united rank and file dominating the alpha-male types” (66).
            The implications for theories about our ancestors are profound. The groups humans were living in as they evolved the traits that made them what we recognize today as human were highly motivated and well-equipped to both prevent and when necessary punish the type of free-riding that evolutionary psychologists and other selfish gene theorists insist would undermine group cohesion. Boehm makes this point explicit, writing,
The overall hypothesis is straightforward: basically, the advent of egalitarianism shifted the balance of forces within natural selection so that within-group selection was substantially debilitated and between-group selection was amplified. At the same time, egalitarian moral communities found themselves uniquely positioned to suppress free-riding… at the level of phenotype. With respect to the natural selection of behavior genes, this mechanical formula clearly favors the retention of altruistic traits. (199)
This is the point where he picks up the argument again in Moral Origins. The story of the homicidal man named /Twi is an extreme example of the predictable results of overly aggressive behaviors. Any nomadic forager who intransigently tries to throw his weight around the way alpha male chimpanzees do will probably end up getting “porcupined” (158) like /Twi and the three men depicted in the Magdalenian cave art in Spain.
Bone from 200,000 years ago shows marks made by multiple
butchers. Soon after this period, butchering began to be
delegated to individuals. 
Murder is an extreme example of the types of free-riding behavior that nomadic foragers reliably sanction. Any politically overbearing treatment of group mates, particularly the issuing of direct commands, is considered a serious moral transgression. But alongside this disapproval of bossy or bullying behavior there exists an ethic of sharing and generosity, so people who are thought to be stingy are equally disliked. As Boehm writes in Hierarchy in the Forest, “Politically egalitarian foragers are also, to a significant degree, materially egalitarian” (70). The image many of us grew up with of the lone prehistoric male hunter going out to stalk his prey, bringing it back as a symbol of his prowess in hopes of impressing beautiful and fertile females, turns out to be completely off-base. In most hunter-gather groups, the males hunt in teams, and whatever they kill gets turned over to someone else who distributes the meat evenly among all the men so each of their families gets an equal portion. In some cultures, “the hunter who made the kill gets a somewhat larger share,” Boehm writes in Moral Origins, “perhaps as an incentive to keep him at his arduous task” (185). But every hunter knows that most of the meat he procures will go to other group members—and the sharing is done without any tracking of who owes whom a favor. Boehm writes,
The models tell us that the altruists who are helping nonkin more than they are receiving help must be “compensated” in some way, or else they—meaning their genes—will go out of business. What we can be sure of is that somehow natural selection has managed to work its way around these problems, for surely humans have been sharing meat and otherwise helping others in an unbalanced fashion for at least 45,000 years. (184)
Following biologist Richard Alexander, Boehm sees this type of group beneficial generosity as an example of “indirect reciprocity.” And he believes it functions as a type of insurance policy, or, as anthropologists call it, “variance reduction.” It’s often beneficial for an individual’s family to pay in, as it were, but much of the time people contribute knowing full well the returns will go to others.
            Less extreme cases than the psychopaths who end up porcupined involve what Boehm calls “meat-cheaters.” A prominent character in Moral Origins is an Mbuti Pygmy man named Cephu, whose story was recounted in rich detail by the anthropologist Colin Turnbull. One of the cooperative hunting strategies the Pygmies use has them stretching a long net through the forest while other group members create a ruckus to scare animals into it. Each net holder is entitled to whatever runs into his section of the net, which he promptly spears to death. What Cephu did was sneak farther ahead of the other men to improve his chances of having an animal run into his section of the net before the others. Unfortunately for him, everyone quickly realized what was happening. Returning to the camp after depositing his ill-gotten gains in his hut, Cephu hears someone call out that he is an animal. Beyond that, everyone was silent. Turnbull writes,
Cephu walked into the group, and still nobody spoke. He went to where a youth was sitting in a chair. Usually he would have been offered a seat without his having to ask, and now he did not dare to ask, and the youth continued to sit there in as nonchalant a manner as he could muster. Cephu went to another chair where Amabosu was sitting. He shook it violently when Amabosu ignored him, at which point he was told, “Animals lie on the ground.” (Quoted 39)
Thus began the accusations. Cephu burst into tears and tried to claim that his repositioning himself in the line was an accident. No one bought it. Next, he made the even bigger mistake of trying to suggest he was entitled to his preferential position. “After all,” Turnbull writes, “was he not an important man, a chief, in fact, of his own band?” At this point, Manyalibo, who was taking the lead in bringing Cephu to task, decided that the matter was settled. He said that
there was obviously no use prolonging the discussion. Cephu was a big chief, and Mbuti never have chiefs. And Cephu had his own band, of which he was chief, so let him go with it and hunt elsewhere and be a chief elsewhere. Manyalibo ended a very eloquent speech with “Pisa me taba” (“Pass me the tobacco”). Cephu knew he was defeated and humiliated. (40)
The guilty verdict Cephu had to accept to avoid being banished from the band came with the sentence that he had to relinquish all the meat he brought home that day. His attempt at free-riding therefore resulted not only in a loss of food but also in a much longer-lasting blow to his reputation.
            Boehm has built a large database from ethnographic studies like Lee’s and Turnbull’s, and it shows that in their handling of meat-cheaters and self-aggrandizers nomadic foragers all over the world use strategies similar to those of the Pygmies. First comes the gossip about your big ego, your dishonesty, or your cheating. Soon you’ll recognize a growing reluctance of other’s to hunt with you, or you’ll have a tough time wooing a mate. Next, you may be directly confronted by someone delegated by a quorum of group members. If you persist in your free-riding behavior, especially if it entails murder or serious attempts at domination, you’ll probably be ambushed and turned into a porcupine. Alexander put forth the idea of “reputational selection,” whereby individuals benefit in terms of survival and reproduction from being held in high esteem by their group mates. Boehm prefers the term “social selection,” however, because it encompasses the idea that people are capable of figuring out what’s best for their groups and codifying it in their culture. How well an individual internalizes a group’s norms has profound effects on his or her chances for survival and reproduction. Boehm’s theory is that our consciences are the mechanisms we’ve evolved for such internalization.
Though there remain quite a few chicken-or-egg conundrums to work out, Boehm has cobbled together archeological evidence from butchering cites, primatological evidence from observations of apes in the wild and in captivity, and quantitative analyses of ethnographic records to put forth a plausible history of how our consciences evolved and how we became so concerned for the well-being of people we may barely know. As humans began hunting larger game, demanding greater coordination and more effective long-distance killing tools, an already extant resentment of alphas expressed itself in collective suppression of bullying behavior. And as our developing capacity for language made it possible to keep track of each other’s behavior long-term it started to become important for everyone to maintain a reputation for generosity, cooperativeness, and even-temperedness. Boehm writes,
Ultimately, the social preferences of groups were able to affect gene pools profoundly, and once we began to blush with shame, this surely meant that the evolution of conscientious self-control was well under way. The final result was a full-blown, sophisticated modern conscience, which helps us to make subtle decisions that involve balancing selfish interests in food, power, sex, or whatever against the need to maintain a decent personal moral reputation in society and to feel socially valuable as a person. The cognitive beauty of having such a conscience is that it directly facilitates making useful social decisions and avoiding negative social consequences. Its emotional beauty comes from the fact that we in effect bond with the values and rules of our groups, which means we can internalize our group’s mores, judge ourselves as well as others, and, hopefully, end up with self-respect. (173)
Social selection is actually a force that acts on individuals, selecting for those who can most strategically suppress their own selfish impulses. But in establishing a mechanism that guards the group norm of cooperation against free riders, it increased the potential of competition between groups and quite likely paved the way for altruism of the sort Leacock’s informant Thomas displayed. Boehm writes,
Thomas surely knew that if he turned down the pair of hungry men, they might “bad-mouth” him to people he knew and thereby damage his reputation as a properly generous man. At the same time, his costly generosity might very well be mentioned when they arrived back in their camp, and through the exchange of favorable gossip he might gain in his public esteem in his own camp. But neither of these socially expedient personal considerations would account for the “dead” feeling he mentioned with such gravity. He obviously had absorbed his culture’s values about sharing and in fact had internalized them so deeply that being selfish was unthinkable. (221)
In response to Ghiselin’s cynical credo, “Scratch an altruist and watch a hypocrite bleed,” Boehm points out that the best way to garner the benefits of kindness and sympathy is to actually be kind and sympathetic. He points out further that if altruism is being selected for at the level of phenotypes (the end-products of genetic processes) we should expect it to have an impact at the level of genes. In a sense, we’ve bred altruism into ourselves. Boehm writes,
If such generosity could be readily faked, then selection by altruistic reputation simply wouldn’t work. However, in an intimate band of thirty that is constantly gossiping, it’s difficult to fake anything. Some people may try, but few are likely to succeed. (189)
The result of the social selection dynamic that began all those millennia ago is that today generosity is in our bones. There are of course circumstances that can keep our generous impulses from manifesting themselves, and those impulses have a sad tendency to be directed toward members of our own cultural groups and no one else. But Boehm offers a slightly more optimistic formula than Ghiselin’s:
I do acknowledge that our human genetic nature is primarily egoistic, secondarily nepotistic, and only rather modestly likely to support acts of altruism, but the credo I favor would be “Scratch an altruist, and watch a vigilant and successful suppressor of free riders bleed. But watch out, for if you scratch him too hard, he and his group may retaliate and even kill you. (205)

Read Part 1: The Groundwork Laid by Dawkins and Gould.
And Part 2: Steven Pinker Falls Prey to the Averaging Fallacy.
Also of interest: The Adaptive Appeal of Bad Boys