Apr 20, 2008
Peace Among Primates (Part 3)
Anyone who says peace is not part of human nature knows too little about primates, including ourselves.
–By Robert M. Sapolsky
Natural born killers?
Are there any lessons to be learned here that can be applied to human-on-human violence apart, that is, from the possible desirability of giving fatal cases of tuberculosis to aggressive people? Can human behavior be as malleable and as peaceful as Forest Troops?
Any biological anthropologist opining about human behavior is required by long-established tradition to note that for 99 percent of human history, humans lived in small, stable bands of related hunter-gatherers. Game theorists have shown that a small, cohesive group is the perfect setting for the emergence of cooperation: The identities of the other participants are known, there are opportunities to play games together repeatedly (and thus the ability to punish cheaters), and there is open-book play (players can acquire reputations). And so, those hunter-gatherer bands were highly egalitarian. Empirical and experimental data have also shown the cooperative advantages of small groups at the opposite human extreme, namely in the corporate world.
But the lack of violence within small groups can come at a heavy price. Small homogenous groups with shared values can be a nightmare of conformity. They can also be dangerous for outsiders. Unconsciously emulating the murderous border patrols of closely related male chimps, militaries throughout history have sought to form small, stable units; inculcate them with rituals of pseudokinship; and thereby produce efficient, cooperative killing machines.
Is it possible to achieve the cooperative advantages of a small group without having the group reflexively view outsiders as the Other? One often encounters pessimism in response to this question, based on the notion that humans, as primates, are hard-wired for xenophobia. Some brain-imaging studies have appeared to support this view in a particularly discouraging way. There is a structure deep inside the brain called the amygdala, which plays a key role in fear and aggression, and experiments have shown that when subjects are presented with a face of someone from a different race, the amygdala gets metabolically active aroused, alert, ready for action. This happens even when the face is presented subliminally, which is to say, so rapidly that the subject does not consciously see it.
More recent studies, however, should mitigate this pessimism. Test a person who has a lot of experience with people of different races, and the amygdala does not activate. Or, as in a wonderful experiment by Susan Fiske, of Princeton University, subtly bias the subject beforehand to think of people as individuals rather than as members of a group, and the amygdala does not budge. Humans may be hard-wired to get edgy around the Other, but our views on who falls into that category are decidedly malleable.
In the early 1960s, a rising star of primatology, Irven DeVore of Harvard University, published the first general overview of the subject. Discussing his own specialty, savanna baboons, he wrote that they “have acquired an aggressive temperament as a defense against predators, and aggressiveness cannot be turned on and off like a faucet. It is an integral part of the monkeys personalities, so deeply rooted that it makes them potential aggressors in every situation. Thus the savanna baboon became, literally, a textbook example of life in an aggressive, highly stratified, male-dominated society. Yet in my observation of Forest Troop, I saw members of that same species demonstrate enough behavioral plasticity to transform their society into a baboon utopia.
The first half of the twentieth century was drenched in the blood spilled by German and Japanese aggression, yet only a few decades later it is hard to think of two countries more pacific. Sweden spent the 17th century rampaging through Europe, yet it is now an icon of nurturing tranquility. Humans have invented the small nomadic band and the continental megastate, and have demonstrated a flexibility whereby uprooted descendants of the former can function effectively in the latter. We lack the type of physiology or anatomy that in other mammals determine their mating system, and have come up with societies based on monogamy, polygyny, and polyandry. And we have fashioned some religions in which violent acts are the entrance to paradise and other religions in which the same acts consign one to hell. Is a world of peacefully coexisting human Forest Troops possible? Anyone who says, “No, it is beyond our nature, knows too little about primates, including ourselves.
— Robert M. Sapolsky, Ph.D., is the John A. and Cynthia Fry Gunn Professor of Biological Sciences and a professor of neurology and neurological sciences at Stanford University. He wrote the classic Why Zebras Don’t Get Ulcers: An Updated Guide to Stress, Stress Related Diseases and Coping. His most recent book is Monkeyluv: And Other Essays on Our Lives as Animals. A longer version of this essay appeared in Foreign Affairs. We bring you this post thanks to our collaboration with Greater Good Magazine, a UC-Berkeley-based quarterly magazine that highlights ground breaking scientific research into the roots of compassion and altruism.