Wired for Culture: Origins of the Human Social Mind (13 page)

At the same time, if we accept the view of our cultures as survival vehicles, the nature of our altruism can also help us to understand some jarring facts about our social behavior. It is a melancholy feature of our species that there are two situations in our everyday lives in which humans can act with such explosive violence toward others as to make us question if it is ever safe to trust another of our kind, and both of these are linked to protecting our societies. One is when trust unravels between two tribal or ethnic groups, and uncontrolled slaughter breaks out. In a period of one hundred days in 1994, Hutu tribesmen in Rwanda massacred somewhere around 800,000 Tutsi tribal people in a terrible spasm of violence. There were no weapons of mass destruction and few modern tools of warfare. Most of the killers were armed with clubs and machetes. People who had lived near to each other for generations descended into a maelstrom of genocide, chasing down, cornering, and then hacking and chopping each other to death.

The other situation arises when we turn on each other within our own group or society over what is taken to be a defection by one person against the social norms that glue society together. When this happens, humans are capable of abandoning the restraints that normally govern their actions toward members of their own group. Some of the people the Hutu killed were other Hutu, their crime being to be committed to peace with the Tutsis. In 2008, a woman in a South London grocery shop summoned her boyfriend to confront a man she claimed had jumped the line in front of her. The boyfriend smashed the other man in the face, knocking him down and killing him. Life can be cheap in human societies: the dead man hadn’t in fact jumped the line, and it was a line to buy a packet of cigarettes. Two young boys were beaten to death with wooden bats in Pakistan in late 2010 for carrying a cricket bag. The bag resembled one some thieves had stolen earlier that day. But the boys were simply on their way to play cricket.

These are not isolated incidents. If the anthropological accounts of our history are correct, there are good reasons to believe that natural selection has not only favored in us a willingness to kill other members of our own species, it has equipped us with a set of dispositions that make it alarmingly easy for us to do so. Just consider that the action our societies reserve their greatest moral sanctions against—murder—can earn someone that society’s highest honor, if directed at the right kind of person in war. In the absence of evidence to the contrary, it would seem that humans are capable of throwing a switch in their minds that allows them, even with little or no provocation, to treat members of other societies—and even in some circumstances their own—as something considerably less than human in moral terms. The supreme and unhappy irony of our species is that these behaviors are connected. Both arise out of the fragility of our “special” and “limited” form of altruism toward people who are not related to us.

The first—our tendency toward
parochialism
, or a disposition to be hostile toward people outside of our groups—has a simple, if disturbing, explanation. As our societies occupied the world after leaving Africa beginning around 60,000 years ago, they would not just have replaced the premodern populations of
Homo erectus
and the Neanderthals in their paths, they would have increasingly encountered other modern human populations like themselves, looking to occupy the same territories. To survive, our cultures, like the vehicles of any other organism, would have had to evolve the means to compete against other cultures. Other human cultures would be our most natural competitors, and so we can expect that our history has been characterized by a to-and-fro arms race of societies meeting each other’s improvements at warfare with countermeasures of their own. If holding a parochial or hostile view toward outsiders makes it easier for you to kill them in battle, parochial dispositions might have spread as good ways to end any particular arms race. But if so, dispositions to commit oneself in battle—even including a disposition to give your own life—might have been necessary in return.

The second—our ability to turn on members of our own society when we think they threaten its integrity—is sometimes called
moralistic aggression
, and is more subtle. When we rebuke people for deviating from norms, shout at or honk our horns at people who jump lines, or worse kill them, these are ways of punishing someone who has shown from their actions that they do not share the altruistic dispositions on which our shaky but valuable form of cooperation rests. They lose the special and limited sense in which they are honorary relatives by demonstrating that they are not related to us at the
altruism locus
that underpins our joint cooperation. This might tell us that our societies are worth protecting, but doesn’t explain the ease with which we can so violently turn on someone from within our own group. But, of course, moralistic aggression is as easy to evolve in our societies as parochialism is toward those outside—in both cases, our aggression is directed at someone not related to us. Once someone has shown by their actions that they do not share your disposition at your altruism locus, it doesn’t matter whether they are in your tribe or not—their relatedness has fallen to zero. This is why it was easy for Hutu to kill other Hutu who had sided with Tutsi.

A quote often attributed to the Roman orator and lawyer Cicero tells us that moralistic aggression is conceivably an even stronger and harsher emotion than parochialism:

A nation can survive its fools, and even the ambitious. But it cannot survive treason from within. An enemy at the gates is less formidable, for he is known and he carries his banners openly. But the traitor moves among those within the gate freely, his sly whispers rustling through all the alleys, heard in the very hall of government itself. For the traitor appears not a traitor—he speaks in the accents familiar to his victims, and wears their face and their garment, and he appeals to the baseness that lies deep in the hearts of all men. He rots the soul of a nation—he works secretly and unknown in the night to undermine the pillars of a city—he infects the body politic so that it can no longer resist. A murderer is less to be feared… .

The physicist Steven Weinberg has said, “With or without religion, good people can behave well and bad people can do evil; but for good people to do evil—that takes religion.” Weinberg’s remark is something of a rallying war cry among those who decry the evils of religion, but it is sophomoric and naive. As the previous examples show, it hardly takes religion for good people to do evil things, unless Weinberg thinks Hutus are all innately evil, or that Hutu is a religion. The causes of the massacre are still debated, but there is no suggestion that this was a religious war. Instead, Hutus are agriculturalists or farmers and Tutsis are pastoralists who herd cows. Both need land, and where pastoralists and agriculturalists overlap, there is often conflict over who gets it. All it takes, then, is for something to spark violence into action and our culturally defined parochial tendencies can take over.

Another physicist, Stephen Hawking, seems to get closer to the truth. Hawking warns that we should expect the very human tendency to exploit new lands and the people and animals that inhabit them to be true of any aliens who might visit us, noting: “If aliens visit us, the outcome would be much as when Columbus landed in America, which didn’t turn out well for the Native Americans… . We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet.” It is easy to be amused at Hawking’s alarm, but we may have been something we would not want to meet for at least the last 60,000 years, maybe much longer. In
War Before Civilization,
Lawrence Keeley documents how battles, raids, and massacres have occurred in our past at far higher rates that in modern nation-states, and mortality rates were far higher than in modern combat, sometimes exceeding 10 percent of the local population in a single massacre. That would be like a country the size of the United States losing 30 million people in one battle. Rates of homicide among the San Bushmen—long fabled as a peaceful society and sometimes called “the harmless people”—exceed those of industrialized democracies. Keeley’s conclusions are remarkably similar to those reported by Steven LeBlanc and K. E. Register in their book
Constant Battles
, whose title is intended as a description of our hunter-gatherer history.

Humans have routinely throughout our history treated members of other racial or ethnic groups with hostility and wanton violence, torture, massacres, and disfigurement. Keeley recounts how in Tahiti, a victorious warrior would pound his dead foe’s corpse flat using a heavy war club, then slit open the flattened body and wear it as a trophy. Some think this level of aggression is an anomaly caused by malign Western influence; or that it is only true of modern agriculturalists, whose possession of crops means they have something to defend and something worth stealing; or that it is limited to a few psychopaths. But such views are simply incompatible with what we know of our species. The evidence is now undeniable that conflict has been a routine and debilitating feature of our history, with high levels of violence documented for many hunter-gatherer societies. One often quoted survey from 1978 by the anthropologist Carol Ember, entitled “Myths About Hunter-Gatherers,” revealed that somewhere around two thirds of them waged some form of war at least every two years. The study is technically flawed, but even accounting for those flaws, war has never been very far from our doorstep.

We should not be surprised. We were the species that discovered the division of labor and the cooperative dispositions that allowed it to work. Together, these developments allowed us to assemble and deploy what was by anyone’s reckoning a formidable fighting machine of specialized and cooperative warriors. But our tendency to aggression goes even deeper than this, right back to our breaking of what we called the “rule of two.” It is likely that wherever we have gone, we have filled up our environments to their carrying capacities. In earlier times as hunter-gatherers this might not have meant very many people per square mile of land, but they were still at their carrying capacity because hunting-and-gathering is an inefficient way to use land. So once we had spread around the word, there never would have been a time when great tracts of usable land lay unused. Neighboring groups, each at their respective carrying capacities, will therefore always wish to have the land next door, and killing off those neighbors would have been a good way to get it.

This might have been the fate of Ötzi, the Ice Man, the 5,300-year-old man whose body was discovered in 1991 sticking out of the end of a glacier on Tisenjoch Pass in the Alps spanning the Italian-Austrian border. Ötzi (the name given him by researchers who studied his remarkably well-preserved body) was fully clothed and carrying a bow and arrow. He was wearing shoes made of brown bearskin, with deerskin side panels that were drawn up tight around his feet using a bark-string net inside the shoe. Anthropologists speculated that he was a shepherd who might have fallen into a crevasse and frozen to death. But the more Ötzi was studied, the more this story seemed incomplete. Ötzi turned out to be armed to the teeth. In addition to his bow and arrow, he carried a dagger and a hafted ax. But it was only when the body was finally X-rayed that the cause of his death became clear. Ötzi had an arrow embedded deep in his chest. He probably froze to death fleeing his attackers.

Measured in terms of their cost to society, the Trident nuclear submarines of their day might have been the Maori war canoes. They could be 100 feet long and hewn from a single tree felled in the forests of New Zealand (or Aotearoa, as it is known to Maori), then hollowed out to produce the hull. The hull would have been filled with seats, riggings for oars, and space for up to fifty-five paddlers and seventy warriors. New Zealand’s Auckland Museum contains the last one of these to be built, known as
Te Toki a Tapiri
, carved in the middle of the nineteenth century from a single totara tree (
Podocarpus totara
). It is 82 feet long, painted, ornamented, and decorated, and would have required hundreds of hours of work from scores of laborers. And yet this canoe would not have contributed food or shelter or help to rear young or look after the elderly, or treat disease. It would have consumed a considerable portion of a tribe’s “gross domestic product,” but it was built exclusively to mount raids on other tribes, and to defend the tribe against others wishing to do the same to them.

The practice of slavery is not simply a moral stain on the fabric of seventeenth- to nineteenth-century British and American soci-eties. Nearly every human group that has ever been studied has at one time or another kept people against their will and used them in a slave capacity. Arab slave traders bought people from East Africa perhaps as early as from the eighth century onward, and in fact one can still see the slave auction blocks in the modern tourist destination of Zanzibar, just off the Tanzanian coast. Pacific Northwest Coast Native American tribes captured slaves from each other. In Oceania, some Samoan and Maori groups practiced slavery, as was true of western regions of New Guinea. Ancient Greece and Rome imported slaves from Africa, and some African slaves were sold as far away as China. Slavery was common in India, and modern-day Pygmy communities often live in an economically subservient capacity to nearby farmers. What we regard in modern society as morally reprehensible acts are all too predictable from the nature of our societies and the nature of our cooperation. Slaves are not members of our groups, and as such lose that precious degree of cultural relatedness that only barely knits our own societies together. As we have seen, once that fleeting bit of relatedness is removed, humans seem to have the capacity to lose their normal moral restraints, using others in whatever ways serve their interests.

Aggression toward members of our own societies is not even limited to people whom we think have violated the cooperative pacts they rest on. For the same reason that moralistic aggression is easily evolved, so too is it easy for our societies simply to rid themselves of people who can no longer contribute, even though this is now something we regard as obscene in modern societies. The Aché (ah-CHAY) are a tribe of hunter-gatherers living deep inside a remote part of the Amazonian rain forest. They did not make contact with the outside world until late into the twentieth century, and were living what most of us would think of as a Stone Age existence. The anthropologists Kim Hill and Magdalena Hurtado lived among the Aché for years. They report that killing of members of their own group is common, especially children whose parents have died, and adults who are injured or potentially fatally diseased.