Rousseau and Hobbes, Sitting in a Tree…

Rousseau thought that people by nature were peaceful unless corrupted by civilization. Hobbes thought people were violent unless civilized by society.  Both were right. Evolutionary biologist and Harvard professor Richard Wrangham addresses this duality in his book The Goodness Paradox: The Strange Relationship between Virtue and Violence in Human Evolution. Wrangham, who had studied in the field with Jane Goodall, is also the author of Catching Fire: How Cooking Made Us Human and is co-director of the Kibale Chimpanzee Project. He sees the key to the paradox in the distinction between between proactive and reactive aggression.

Reactive aggression is the tendency to respond with threats (such as hisses, growls, and roars) and violence when approached, whether by a member of another species or one’s own. Most animals including our cousins the chimpanzees – particularly (but not exclusively) males – typically act this way not just to strangers but to members of their own pack or social group. Humans rarely do. He notes that 300 chimpanzees never would sit quietly side by side for hours; fights would break out and (with nowhere to run) fatalities would be likely. Yet humans do that on planes and in movie houses all the time. However often bar fights and physical assaults may be on the news, the remarkable thing is how rare they are among humans. We are more tolerant even than bonobos, the mild-tempered close relatives of chimpanzees. We share this level of tolerance only with domestic animals, which have been deliberately bred for this temperament.

People domesticated animals, but who domesticated people? Wrangham argues (as others have before him) that our ancestors did it to themselves by ganging up on any overly violent, dominant, or annoying individual, who was then killed or ostracized and thereby removed from the gene pool. (Remaining hunter-gatherers still do this.) Sociality became a reproductive advantage. Bonobos, whose environmental pressures differ from those on chimps by favoring more social tolerance, did something similar to themselves. Not having language, the capacity of bonobos to stir up conspiracies against bullies is much more limited and the results therefore less extreme than among humans. This ganging up is, of course, proactive aggression. The extensive planning permitted by language made humans’ proactive aggression deadly on an unprecedented scale whether against actual outsiders (e.g. World War One: see my recent review of the documentary They Shall Not Grow Old) or against undesired members of their own social groups.

Domestic animals share a large number of traits that are incidentally related to the primary one of social tolerance, including neoteny, smaller teeth, and smaller brains. This is true even of relatively smart domestic animals; dogs, for instance, have smaller brains than their wolf ancestors of comparable size. Humans, too, have those traits. After millions of years of growing larger, human brains shrank some 15% from their Stone Age peak, reaching their current size many thousands of years before farming (so the reduction was unrelated to it). Apparently, beyond a certain level of population density (still extraordinarily sparse by modern standards), being social conferred more reproductive benefits than being smart.

There remain people who are violent for the fun of it (i.e. criminals), of course, but they are few by ape standards. However, humans are unmatched (in fact, unique) in our capacity for moralistic violence: our intelligence and our language skills let us identify as “other” those with the wrong ideology, religion, accent, or whatever, and enable us to whip up moral outrage against them. The most horrific mass killings are by moralists who think that they are doing the right thing – even the obligatory thing. They are not criminals in the usual sense, and are likely to be kind and polite people in everyday life. As an example, Wrangham relates the story of anthropologist Alexander Hinton who investigated the ideologically driven Cambodian massacres of the 1970s that killed nearly 2,000,000 people. Hinton was disconcerted by a former Khmer Rouge named Lor who openly stated he had killed many men, women, and children: “I saw before me a poor farmer in his late thirties, who greeted me with the broad smile and polite manner that one so often encounters in Cambodia.” Says Wrangham, “So the definition of morality that I will follow here is not limited to altruism or cooperation. I take moral behavior to be behavior guided by a sense of right and wrong… We sometimes think that cooperation is always a worthwhile goal. But just like morality, it can be for good or bad.”

Mae West: “What is this, propaganda?”

So, our better natures have their roots in aggression. However, Wrangham does not suggest that we need to continue a social strategy just because it has evolutionary roots. He opposes capital punishment, for example, as no longer necessary even though we may well owe our peaceful natures to it. We are big brained creatures, after all, (despite the late Paleolithic shrinkage) and we can choose to be better. Most of the time we do. “The one guarantee that an evolutionary analysis can offer, however, is that it will not be easy for fairer and more peaceful societies to emerge.” Fortunately, our harsh ancestors gave us the cooperative skills to make that possible.

Bessie Smith - A Good Man is Hard to Find (1927)