This is part 2 of my review of Steven Pinker's "The Better Angels of Our Nature". Read Part 1 here.
The most famous human being of prehistoric times is probably Otzi the Iceman, a Neolithic human whose mummified body was discovered frozen in a glacier in the Alps in 1991. What's less well known about Otzi is that he met his death violently: an arrowhead was lodged in his back, and he was carrying an arrow and a flint knife which had traces of three people's blood, none of them his own. Anthropologists speculate that he was part of a raiding party that attacked a rival tribe and was killed while making his escape. A fourth blood type found on his coat suggested he could have been carrying a wounded ally.
Otzi's death is a microcosm of the theories of Thomas Hobbes, the famous Enlightenment political theorist who argued that, before government, human life was "solitary, poor, nasty, brutish and short." Hobbes' classic book Leviathan asserted that to end the bloodshed of primitive times and improve their living conditions, people came together and agreed on a social contract, to create a government which holds a monopoly on force and adjudicates disputes between individuals. Although Hobbes was theorizing from his armchair, Pinker argues that the evidence has largely proven him correct. Life before government wasn't exactly Hobbes' war of all against all, but it was close.
To support this, Pinker cites anthropological and archaeological data which show that, when you rank the most violent societies in the world - those where people have the highest lifetime chance of dying at another's hand - it turns out that the top of the list isn't occupied by modern states, with all their machinery of war, nor even by the aggressively expansionist and colonial empires of history discussed in the last installment. Rather, the most violent societies on earth are the tribal, hunter-gatherer cultures that were ubiquitous in the past and still exist today in isolated and remote regions of the planet. In some of the most warlike, people had a lifetime chance as high as fifty percent of being the victim of homicide, not even counting deaths from accidents or disease. (These conclusions are undergirded by, for example, archaeological surveys of ancient graves to see how many of the skeletons bear marks of lethal violence.) This chart from Pinker's book shows some of the data [p.49].
Why are hunter-gatherer cultures so violent? Pinker locates the answer in the self-serving biases of human nature: people tend to exaggerate the harms they suffer and downplay the harms they inflict on others, which causes both parties in a conflict to think of themselves as innocent victims and the other side as treacherous aggressors. As a result, in a stateless society with no central authority to restrain them, minor feuds can quickly spiral out of control into endless cycles of retributive bloodshed. In short, Thomas Hobbes got it right: the centralized state, the Leviathan, reduces violence by enforcing an impartial justice on all its citizens, rather than people taking the law into their own hands.
Pinker uses this as a lead-in to his discussion of why the "hydraulic" metaphor, which treats violence as an impulse that constantly builds up and must periodically be discharged, is wrong. Violence isn't hydraulic, but an evolutionary strategy deployed under certain limited and well-understood circumstances predicted by game theory: to take something valuable away from a rival, like food or mates; to sneak-attack an enemy in an act of preemptive defense; or to maintain one's reputation in the face of insult, threat or challenge.
We still see this today in our primate cousins, the chimpanzees. When they encounter each other while foraging in disputed territory, chimp bands from rival clans will bark, scream, throw stones, and engage in other noisy, showy displays of threats and boasting that usually end in stalemate. But the real bloodshed comes in the form of sneak attacks: if a chimp band encounters a single male from another tribe, they'll usually pounce and tear him apart. Sometimes chimpanzees form "raiding parties" that gradually pick off rival tribes one member at a time, the chimp equivalent of genocide [p.37].
As Pinker says, a similar dynamic still exists in isolated regions of the Earth where tribal people live in Stone Age-level societies, like the deep Amazon or the mountain highlands of New Guinea. In those places, if you see a member of another tribe, the usual response is to either run away or immediately try to kill them. In societies of only a few hundred people, these constant skirmishes can take a significant toll in lives. But to settle feuds more conclusively, men will sometimes form raiding parties to ambush a rival village at night, setting fire to their huts and spearing or shooting the panicked survivors as they flee into the open. It's not that they enjoy this kind of existence: as one man of the Amazon's Yanomamo tribe told an anthropologist, "We are tired of fighting. We don't want to kill anymore. But the others are treacherous and cannot be trusted." [p.46]
As the Yanomamo dilemma shows, violence is a prisoner's-dilemma problem. If everyone else is violent, it pays to be violent, because being a pacifist under those conditions is a sure way to get enslaved or killed. But if everyone else is peaceful, it still pays to be violent, because then you can enforce your will on people who can't resist. This dire calculus guarantees that natural selection, whether we like it or not, will produce creatures who have the capability to commit violence when they perceive that it will benefit them. (Homer put it best in the Iliad when he said that vengeance was "far sweeter than flowing honey... in the breasts of man". [p.47]) The only way to tamp down violence is to create a counterbalancing force which shifts the incentive structure and ensures that it's no longer a winning strategy: in other words, a government.
The first societies on Earth, of course, were cruel monarchies and theocracies - not much of an improvement. But even a dictator, if rational, will stamp out feuds and strife between his subjects, because it reduces his power and his resource base for his people to fight each other in mutual destruction. Thus, the formation of the first true states, as brutal as they were, was a small step forward in reducing violence. Obviously, we've done much better since then. Pinker cites evidence to show that the old maxim which says that democracies never go to war, while not invariably true, does generally hold: on average, democracies are more peaceful than dictatorships, both internally and externally [p.283, 337]. It's this civilizing process that's been the main driver of peace throughout historical time, resulting in modern societies that are, by ancient standards, almost unimaginably stable and peaceful.
Coming up: Some additional historical forces that promote peace: capitalism, the printing press, and IQ tests!