DEMONIC MALES: Apes and the Origins of Human Violence

DEMONIC MALES: Apes and the Origins of Human Violence. By Richard Wrangham and Dale Peterson. Houghton Mifflin. 350 pp. $24.95

Why are men aggressive? For centuries, there have been only two explanations: original sin and human culture. Now come Wrangham, professor of anthropology at Harvard University, and Peterson, a professional writer, to offer a third possible explanation: the biological heritage we humans share with the great apes.

The authors begin with Wrangham’s observation, in 1973, of a party of male chimpanzees raiding a neighboring community and savagely killing a lone male. Not food, not sex, not even territory was at issue; the act was simple murder. Over the years, researchers in four different African locations have identified similarly lethal raids. “In all four places the pattern appears to be the same,” write the authors.“The male violence that surrounds and threatens chimpanzee communities is so extreme that to be in the wrong place at the wrong time from the wrong group means death.”

While most people know that chimpanzees have humanlike qualities, it is only since 1984, when researchers developed the technique known as DNA hybridization, that chimps have been shown to be genetically closer to humans than to the other great apes. Chimps are more like us than they are like gorillas or gibbons, and not just in killing: males will also rape and batter females. To draw the nexus even tighter, Wrangham and Peterson cite the American anthropologist Napoleon Chagnon’s studies of the Yanomamö tribe of the Amazon Basin. Despite having “not yet been pacified, acculturated, destroyed, or integrated into the rest of the world,” the Yanomamö “are famous for their intense warfare.” Their frequent raids on neighboring villages produce a rate of violent death among young males that is roughly the same—about 25 percent—as it is among chimps.

Among chimps, the size of each gang is determined by the amount of food available. When the best food is scattered, wider-ranging travel is necessary and the gangs are smaller. Females, weaker and burdened by young, can- not keep up. So, with occasional exceptions, the gangs are all male.

Yet gang formation is not universal among the great apes. Among a rare species, the bonobos, there is no rape, battering, or warfare. The reason, says Wrangham, is the abundance of food in the bonobos’ territory, which allows females to travel with males and keep them from forming gangs. The females band together, form their own strong attachments (often involving homosexual behavior), and protect themselves from errant males.

The sole weakness of this book is its neglect of the neurobiology of primate violence. The crucial role of differing serotonin levels in both human and monkey behavior is well known. Individuals with low levels of serotonin exhibit high levels of aggression, and vice versa. It would be useful to know whether similar findings exist with regard to the great apes, but the authors of this otherwise lucid and compelling book do not mention such research.

The authors strongly suggest that human gangs, known to have been present through- out recorded history, are hardly the product of drugs, shoot-’em-up television shows, or bad government policies. Faced with this dispiriting conclusion, the authors explore some ideas about how to control male violence but find few to be effective. Indeed, there is only one reliable method: marriage. When men are married to women, and women have (through countless means, including courts and democratic voting systems) the ability to protect their claims and control demonic males, society becomes more tolerable. Less exciting, perhaps, but more tolerable.