In the history of pseudoscientific theories, some stand out as particularly noxious. One is the claim by 19th-century criminologist Cesare Lombroso that temperament and behavior can be predicted from physiognomy, the structure of the face.

Some men, Lombroso proposed, are born criminals. They are evolutionary throwbacks, “savages” with apish, “atavistic” features. These include big jaws, prominent brows and “handle-shaped ears.” Such men, Lombroso asserted, are prone to “excessive idleness, love of orgies, and the irrepressible craving of evil for its own sake, the desire not only to extinguish life in the victim, but to mutilate the corpse, tear its flesh and drink its blood.”

Lombroso’s lurid hypothesis, while always contested, became extraordinarily popular in the late 19th and early 20th centuries, the heyday of eugenics. In The Mismeasure of Man, his classic critique of scientific attempts to categorize and rank humans, biologist Stephen Jay Gould calls Lombroso’s theory “probably the most influential doctrine ever to emerge from the anthropometric tradition.”

Scientists eventually turned away from biological theories of crime and focused on environmental causes, such as poverty and abuse. But modern researchers, notably Harvard anthropologist Richard Wrangham, are touting the Lombroso-esque claim that men with broad faces are evolutionary throwbacks prone to aggression.

Wrangham is renowned for arguing in his 1997 book Demonic Males that male humans share with chimpanzees an innate propensity for lethal group violence. Various critics, including anthropologist Brian Ferguson and me, have criticized this claim, which I call the deep-roots theory of war. Far from backing down, Wrangham serves up a revamped version of the deep-roots theory in his new book, The Goodness Paradox.

I heard Wrangham summarize themes of his book at a recent symposium on “Our Tribal Nature” (see also his recent paper in Frontiers in Psychology). He distinguishes between two types of male violence, reactive and proactive. Reactive violence is emotional, hotheaded, compulsive, whereas proactive violence is calculating. Think of the difference between a crime of passion and premeditated murder.

Wrangham notes that in modern hunter-gatherer societies, males have been observed to band together, proactively, to execute an out-of-control troublemaker. Something similar happened over and over again during our evolution, Wrangham speculates, and as a result, males evolved to become less compulsively violent, although still all too prone to calculated group aggression.

This evolutionary trend, which Wrangham calls “self-domestication,” resulted in physiological as well as cognitive and behavioral changes. Just as domesticated dogs have narrower faces and smaller jaws and teeth than their ancestors, so do modern humans, according to Wrangham. Relatively undomesticated males still dwell among us, Wrangham suggests, and they can be distinguished by their physiognomy and behavior. Men with broad faces—more specifically, a high facial width-to-height ratio—seem especially prone to aggression, Wrangham said.

Wrangham’s revamped deep-roots thesis poses several problems (some of which have been pointed out in other reviews, see here and here). First, he continues to exaggerate the violence of chimpanzees and human hunter-gatherers. Second, Wrangham claims that biology—a propensity for proactive coalitionary violence—is the root cause of war, but human biology is more or less constant, while war is sporadic. Biology can’t help us understand the difference between Germany in 1935 and today.

Then there is Wrangham’s claim that men whose faces have a high width-to-height ratio are prone to aggression. As evidence he cites a 2008 study, which found that a high facial width-to-height ratio predicts “aggressive behavior” among hockey players (as measured by number of penalties) and college students (as measured by how they played competitive games in a laboratory). Journalists have spread the facial-width meme. “Aggression written in the shape of a man’s face,” proclaimed New Scientist.

But as with the so-called “warrior gene,” carriers of which are supposedly prone to violence, the evidence is flimsy that men with broad faces are innately aggressive. Some studies support the claim, others find no link, not even in hockey players. A 2012 paper reports that “body weight, not facial width-to-height ratio, predicts aggression in pro hockey players.” A massive 2013 study of thousands of subjects from different populations, including Mexican prisoners, concludes that “facial attributes are poor predictors of aggressive behavior.” Wrangham of course fails to mention this contradictory evidence in his recent paper on the self-domestication thesis.

The wide-face hypothesis is morally as well as empirically dubious. Especially when combined with facial-recognition technology, this sort of pseudoscience could lead to systematic discrimination. I’m appalled that modern scientists--especially one as prominent as Wrangham--are promoting what is basically a slur about people with a certain physical appearance. 

Wrangham likes quoting Katherine Hepburn’s famous line in the film The African Queen: “Nature is what we are put in this world to rise above.” What scientists like Wrangham need to rise above is their fondness for absurdly crude biological determinism.

Further Reading:

New Study of Foragers Undermines Claim That War Has Deep Evolutionary Roots

New Study of Prehistoric Skeletons Undermines Claim that War Has Deep Evolutionary Roots

Survey of Earliest Human Settlements Undermines Claim That War Has Deep Evolutionary Roots

New Report on Chimp Violence Fails to Support Deep-Roots Theory of War

New Report on Chimp Violence Fails to Support Deep-Roots Theory of War

Anthropologist Finds Flaw in Claim that Chimp Raids Are Adaptive

Meta-Post: Posts on War and Peace

The End of War (2014 book)