Natural Born Killers?

From Michael P. Ghiglieri's THE DARK SIDE OF MAN: Tracing the Origins of Male Violence

[p. 71] One trait chimps, bonobos, and humans share is the retention of males. Unlike nearly every other social species of mammal, these societies generally retain their males. Meanwhile, females marry into new groups. Anthropologist Carol Ember clarified this pattern by surveying 179 hunter-gatherer societies. She found that only 16 percent of these societies retained their young women more than their young men. Chimp and bonobo social groups also keep their males but transfer their females. Gorillas do the same, although only a few males stay with their fathers. In contrast, orangutans (and almost all other primates) disperse all their males and none of their females. This pattern is significant because this one evolutionary event in the common ancestor of chimps, bonobos, and humans—the retention of males—set the stage for cooperative ape warriors.

[pp. 175-177] It should be noted that male chimps waged war on a neighboring community only when it, the “enemy,” was a lot smaller and weaker than their own community, containing half or fewer adult males. It is no overstatement to say that chimps are Machiavellian—or, to put it another way, politically devious and violent. Men are chimpanzee-like!

These studies of wild chimps tell us that solidarity in aggression among a community’s male kin is their standard strategy to reproduce and that this strategy has been around for a long time. How do we know? Despite their fierce and violent competition, male chimps are only 123 percent the weight of females, evidence that winning against other males no longer hinges on the more primitive orangutan or gorilla strategy of being a huge and formidable individual. Instead, winning depends on group size of male kin who cooperate as an army. Were this a recent evolutionary development, male chimps would be both big and cooperative.

Although chimps teach us what the law of the jungle really means, they also teach us what being social is all about. Sociability is for individual advantage. Within the chimps’ fusion-fission society, each ape’s decisions as to whether to socialize and with whom are based solely on how to best enhance his or her own reproductive success. Thus chimpanzee social structure—violent and otherwise—owes its form ultimately to each individual’s reproductive strategies and, by extension, to each one’s individual decisions. Warfare is simply the social version of combat.

Chimp social structure would be unique were it not for humans acting similarly. This is no coincidence. By most taxonomic criteria, chimps and humans are sibling species. Overall, chimp society is not only extremely sexist—with all adult males dominant over females—but also xenophobic to the extent of killing all alien males, many infants, and some old females who enter their territory. To some readers, my use of the word war may seem too strong to describe what male kin groups do. But systematic, protracted, deliberate, and cooperative brutal killings of every male in a neighboring community, plus genocidal and frequent cannibalistic murder of many of their offspring, followed by usurpation of the males’ mates and annexation of part or all of the losers’ territory, matches or exceeds the worst that humans do when they wage war.

Wild chimps reveal the natural contexts of territoriality, war, male cooperation, solidarity and sharing, nepotism, sexism, xenophobia, infanticide, murder, cannibalism, polygyny, and mating competition between kin groups of males—behaviors that have evolved through sexual selection. Also significant is the fact that none of these apes learned these violent behaviors by watching TV or by being victims of socioeconomic handicaps—poor schools, broken homes, bad fathers, illegal drugs, easy weapons, or any other sociological condition. Nor were these apes spurred to war by any political, religious, or economic ideology or by the rhetoric of an insane demagogue. They also were not seeking an “identity” or buckling under peer pressure. Instead, they were obeying instincts, coded in the male psyche, dictating that they must win against other males.

Nuclear physicist Freeman Dyson warns, “If we are to avoid destruction, we must first of all understand the human and historical context out of which destruction arises. We must understand what it is in human nature that makes war so damnably attractive.”

The great apes, especially chimpanzees, are the best living mirrors of primeval humankind It is up to us to look into that mirror (before we have destroyed all their tropical forests and killed them all) and identify what it is in the human male psyche that makes violence so “damnably attractive.” Now that we have seen the Machiavellian nature of martial chimpanzees, it is time to revisit Homo sapiens.

Are Human Warriors Natural-Born Killers?

IN ALL WARS ever fought by men, some men have killed, while others have avoided doing so. This inconsistency has spurred many idealists to deny that men are instinctive warriors. Instead, they insist, killing must be pounded into each of us against the grain. According to journalist Alessandra Stanley, “Yes, boys have a primitive urge to fight, an easily tapped aggression. But killing is not instinctive; it is an acquired taste, something that grownups must pass on.” Historian Gwynne Dyer likewise claims, ‘Aggression is certainly part of our genetic makeup, and necessarily so, but the normal human being’s quota of aggression will not even cause him to kill acquaintances, let alone wage war against strangers from a different country.”

Both are wrong. People’s “quotas of aggression” are all too often high enough to kill both acquaintances and strangers. During the Vietnam War, for example, Ho Chi Minh’s forces killed fifty-eight thousand Americans. But during the same time span, Americans murdered far more Americans at home—and most of those murdered were acquaintances (or even more intimate). According to political scientists Paul Seabury and Angelo Codevilla, “An ineluctable fact is that human intercourse all too naturally produces circumstances in which reasonable people regard kill or be killed as the best option available.”

This reality is so obvious to biologists that, despite his personal aversion to believing that men are innate killers, German ethologist Irenäus Eibl-Eibesfeldt found himself listing the universal traits of men the world over that are vital to war: loyalty to group members; readiness to react aggressively to outside threats; motivation to fight, dominate, and act territorially; universal fear of strangers; and intolerance of those who deviate from group norms.