Pan Paniscus Apes, more commonly known as bonobos, live peacefully, in part because of the abundant resources in their Congo habitat.
Sapolsky is hardly a starry-eyed optimist. He doubts whether acts of large-scale violence will ever completely vanish. Yes, the threat of war between major powers has declined, he notes, but the ability of small groups or even individuals to wreak enormous havoc—with nuclear, chemical, or biological weapons, not to mention jumbo jets—has grown. “So at a certain level the danger has risen, if not the sheer incidence,” he says. Nonetheless, Sapolsky believes that “there is a great potential for dramatically decreasing the frequency of war and getting a lot better at intervention, termination, and reconciliation.”
De Waal, who met me at the Yerkes center after attending a disarmament workshop in Geneva, agrees that aggression is part of our nature. So too, he adds, are cooperation, conflict resolution, and reconciliation. For decades he has carefully documented how apes and monkeys avoid fights or quickly make up after them by sharing food, grooming each other, or even hugging and kissing.
These traits are especially pronounced in the ape species Pan paniscus. More commonly known as bonobos, they are darker-skinned and more slender than common chimpanzees and have markedly different lifestyles. “No deadly warfare,” de Waal says, “little hunting, no male dominance, and enormous amounts of sex.” Their promiscuity, he speculates, reduces violence both within and between bonobo troops, just as intermarriage does between human tribes. What may start out as a confrontation between two bonobo communities can turn into socializing, with sex between members, grooming, and play.
De Waal suspects that environmental factors contribute to the bonobos’ benign character; food is more abundant in their dense forest habitat than in the semi-open woodlands where chimpanzees live. Indeed, his experiments on captive primates have established the power of environmental factors. In one experiment, rhesus monkeys, which are ordinarily incorrigibly aggressive, grew up to be kinder and gentler when raised with mild-mannered stump-tailed monkeys.
De Waal has also reduced conflict among monkeys by increasing their interdependence and ensuring equal access to food. Applying these lessons to humans, de Waal sees promise in alliances, such as the European Union, that promote trade and travel and hence interdependence. “Foster economic ties,” he says, “and the reason for warfare, which is usually resources, will probably dissipate.”
The question that divides primate researchers—whether war is innate in us and in our hairier kin—has also challenged anthropologist Douglas Fry, whose interest goes back to his teenage years, when the Vietnam War was still raging. He recalls wondering, “Is this something we always have to live with, war after war after war?” His research, says Fry, who left the United States in 1995 to accept a position at Åbo Akademi University in Finland, has led him to reject this conclusion. “Warfare is not inevitable,” he insists in his book Beyond War, because humans “have a substantial capacity for dealing with conflicts nonviolently.”
Fry notes that the earliest widely accepted evidence of possible warfare is a mass grave of skeletons with smashed skulls and hack marks found near the Nile River; the grave dates back some 12,000 to 14,000 years. Such evidence accumulates from later periods as humans around the world abandoned a nomadic existence for a more settled one, leading eventually to the creation of agriculture and states. This evidence consists not only of mass graves but also of weapons clearly designed for fighting, fortified settlements, and rock art depicting battles.
