The debate over the supposed innate propensity of human beings to be aggressive has once again surfaced in the popular press, this time in the current, April, issue of Discover Magazine. (The article is also available for free on the Discover website.) The proponents of the different sides of this discussion are well-known scientists whose arguments are based on their own research and on their literature reviews.

The author, John Horgan, opens by asking if war is really inevitable. He cites studies of college students who overwhelmingly believe that wars will never end, an outlook—humans are naturally aggressive—that has grown increasingly pessimistic in recent decades. The Hobbesian viewpoint is, of course, confirmed by the daily news, and by some scholars in fields such as biology, anthropology, and archaeology. But it is contradicted by other more cautiously optimistic scholars, whose viewpoints are also cited by the author.

Horgan presents the opinions of well-known primatologist Frans de Waal, who has studied the violence of chimpanzees at length. He rejects the notion that violence is a necessary aspect of the behavior of the other primates.

“War is evitable,” de Waal argues. Humans, like the other higher primates, are highly calculating—if war ceases to be profitable, it will cease. He believes that humans have “a tendency, and all the primates have a tendency, to be hostile to non-group members (p.25).”

De Waal is especially interested in the behavior of bonobos, a primate that lives in the Congo forests. They are much less aggressive than chimpanzees, do not engage in warfare, have no male dominance, and engage in a lot of sexual activity, which may serve to reduce violence. Confrontations between bonobo groups may be diverted by grooming, play, socializing, and sex, he says.

Biologist Robert Sapolsky, whose work on the aggressiveness of baboons in Kenya has been reviewed in this website, challenges what he terms the “urban myth of inevitable aggression (p.25).” He argues against the hypothesis that the testosterone levels of male primates increase their natural aggressiveness. “Social conditioning can more than make up for the hormone,” he says.

The author relates the story of Sapolsky’s observations, 20 years ago, of a baboon group which he calls Forest Troop and the dominating behavior of the males. Those male baboons started eating tainted meat from a garbage dump at a tourist lodge and began dying from tuberculosis. After the aggressive males in that troop had died, the group was left with mostly female baboons and less aggressive males.

The behavioral and cultural patterns of the troop changed dramatically—aggressive behavior dropped noticeably. As new, adolescent, males began moving into the troop, they adopted their non-violent ways. Because of the tainted meat, the one baboon troop had become, in so many words, a peaceful primate society.

“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,” Sapolsky concludes.

Horgan also cites the research of Douglas Fry, whose books The Human Potential for Peace and Beyond War: The Human Potential for Peace have been reviewed in this website. Fry insists that “warfare is not inevitable.” His reason: people have “a substantial capacity for dealing with conflicts nonviolently (p.26).”

Fry argues that warfare has not been a long-term, permanent part of human history. The earliest archaeological evidence of human warfare is a mass grave site from about 12,000 to 14,000 years ago near the Nile containing smashed human skulls and hacked bones. He suspects that our ancestors may well have lived much as the hunter-gatherer, nomadic societies that have been documented by anthropologists—with occasional fighting and feuding, but with true warfare mostly absent.

In these societies, third parties often intervene in conflict situations and seek to ameliorate tensions by suggesting ways to avoid violence. Fry cites 74 societies that he calls “non-warring cultures,” a small sample of the thousands of known human societies but enough, he contends, to contradict the notion that ALL human societies fight wars.

Horgan reviews Fry’s literature about the Zapotec society, especially his work with two communities referred to as San Andreas and La Paz. The rate of spouse abuse, child abuse, and male-on-male violence is five times higher in the former town than in the latter. One of the factors that may contribute to the difference between the two towns is the fact that the women of La Paz have a long tradition of making pottery for sale, and their contributions to the family economies of the town may foster respect from the men.

Fry notes that in contemporary Finland, where he teaches today, women play an important role in public life. Finland has a relatively low rate of violence and crime. He doesn’t argue that valuing women or putting them in high government offices will necessarily reduce violence and warfare—he cites Margaret Thatcher as an example of a woman leader that contradicts such a simplification. But he concludes, “there are good reasons for having a balance of the more caring sex in government (p.27).”

Horgan includes in his survey the opinions of scientists who strongly disagree with Fry, Sapolsky, and De Waal. He discusses the work of Richard Wrangham, who has argued that humans have been fighting wars ever since we evolved as a species from our competitive, primate ancestors. He maintains that de Waal exaggerates the importance of the bonobos and he scoffs at Fry’s argument that feuding should be distinguished from warfare.

Archaeologist Steven LeBlanc is also critical of arguments that human nature can be peaceful. According to Horgan, LeBlanc “accuses Fry of perpetuating ‘fairy tales’ about levels of violence among hunter-gatherers and other pre-state people (p.27).” He contends that evidence of warfare can be found throughout human prehistory. Horgan concludes with the opinion of prominent biologist Edward O. Wilson that the propensity for aggression is deeply engrained in human nature and human history.

Horgan, John. 2008 “War—What Is It Good For? Absolutely Nothing.” Discover Magazine April, p. 24-27.