Talk About Gorilla Warfare

Systematic rape, border raids, warfare among rival territorial gangs, frenzied killers drinking victims’ blood and biting off their fingers. . . .

Humans acting like savage beasts?

No, tales of chimpanzees behaving as badly as men.

Scientists have long assumed that Homo sapiens was the only species malevolent enough to kill their own kind. But the death of Godi, an African chimpanzee who was brutally pummeled by a band of marauding chimps in Tanzania in 1974, changed the conventional wisdom. Since then, numerous incidents of blood lust that echo genocidal war reports from Rwanda or Bosnia have been documented among our closest animal relative, which shares roughly 99% of our DNA.

Chimpanzees, considered one of the most violent of mammals, share with humans a pattern of aggression that may explain our “5 million-year habit of male human aggression,” says Richard Wrangham, Harvard anthropologist and MacArthur fellow.

The two species organize themselves into similar social groups, which may help explain why they share a history of unrelenting violence, Wrangham suggests in “Demonic Males: Apes and the Origins of Human Violence” (Houghton Mifflin, 1996), coauthored with Dale Peterson.

“Male humans and chimps have been shaped by 5 billion years of natural selection to respond to certain situations with violence,” says Wrangham, who calls testosterone “the demonic molecule.”

“A combination of things trigger a release of extraordinary violence. One, the perception that you are going to win by greatly outnumbering the victims. The other is a taking advantage of power to gain control. That may be a relationship between two neighboring groups competing for control of land or over a female or group of females.”

Many other adult animals fight within their own species until there is a clear victor, but rarely to the death. Infanticide, however, is widespread among many species, which kill babies either for food or to make a female available for mating.

Social conditions are a crucial link to aggression among both man and chimp. Both species align themselves with male kin and form aggressive all-male coalitions in mutual support against others (the Hatfields versus the McCoys), travel in “party gangs” (making killing others less risky) and will compete with lethal results with members of their own species for territory, sex or resources. Humans, however, unlike chimps, can do more damage using weapons, Wrangham says.

Brutal rape among chimps is widespread. Females, considerably smaller than males, are chased, attacked, beaten, bitten, starved and pushed out of trees by rapist males for the duration of their ovulation, which females cannot conceal.

Working to keep humans’ violent tendencies under control, of course, are our larger brains, language, moral codes, judicial systems, democratic government and self-awareness.

Lest we think aggression is an inevitable “evolutionary hangover,” Wrangham points to the bonobo (Pygmy chimpanzee), one of the most pacific of mammals. A striking example of a feminist world order, bonobos evolved so that the sexes share power, females form alliances against males and murder, mayhem and rape are as yet unknown.

“The bonobos show us a species in which females are able to control male violence,” he says. “There is a distant parallel in [feminist] Naomi Wolf’s thinking that it is kind of ironic that women are the majority but that they are not able to shape society to their own benefit. What she and the bonobos are saying is that women should make sure that their interests coincide and collaborate to change the laws.”

With no competition for food, aggression served no purpose in bonobo society, Wrangham says. The bonobo eats vegetation also consumed by lowland gorillas, but it is plentiful because they don’t share territory with the gorilla or with the more violent chimpanzee.

Top-ranking females dominate lower-ranking males. Bonobos travel in slightly larger groups than chimpanzees, but the groups are coed. Ovulation is concealed so males and females appear to mate to bond and forge friendships. Females make forays into groups of neighboring bonobos, engaging in sex with either gender of the bordering bonobo community. (Males also engage in homosexual sex). And, on the off chance that a male bonobo gets cheeky, a female can call on female allies who descend upon the brute and chase him off.

The bonobos are a model society, Wrangham says. The tragedy for humans, he adds, is that we are more closely related to the bellicose chimp than the gentle bonobo.

“We washed up on the evolutionary shores of the chimps and bonobos,” Wrangham says. “One is the most violent of mammals and one is the most peaceful. It is sort of a cosmic tragedy that the human species is more similar to chimps than to bonobos.”