Violence is down and partly thanks to trade: A scientist explains his bold new thesis

A.Violence has declined, on many scales of time and magnitude, with reductions unfolding over periods stretching from millennia down to just a few years. That’s true for everything from warfare and genocide to our treatment of children and animals.

What is some of the evidence for such a grand claim?

Before states emerged, constant tribal raiding and feuding led to death tolls from violence that averaged about 15 per cent, many times higher than today even aggregating over the twentieth century with all its wars and genocides.

The second notable development is the transition of everyday life from the Middle Ages to the present, which saw about a 35-fold reduction in murders.

Thirdly, humanitarian reforms about the time of the enlightenment ended many barbaric practices, such as torture and mutilation as a form of criminal punishment. In fifteenth-century France, a popular form of entertainment was hoisting a cat in a sling on a stage and watching it howl as it was burned to death. People would bring out the whole family to watch public executions, which were often acts of prolonged torture.

Another development, which people take for granted but military historians are astonished by, is the disappearance of great power war and war between developed countries since the end of World War Two. Now the remnants of war are in the poorer parts of the world and the rich countries seem to have thought better of it.

Of course, it wouldn’t be progress if wars had only ceased in rich countries, but in the last twenty years rates of war all over the world have plummeted. The number of civil wars and the death toll from civil wars are at an all-time postwar low.

Finally, there’s the reduction of violence on smaller scales. In America, a century ago we had 150 lynchings a year; now it’s zero. Domestic violence has come down, rape is down, smacking children is down in most of the western world. Treatment of lab animals is far more humane than when I was a student.

If this is true, why does it seem so surprising?

One reason is that the news media are better and better at reporting violence. We crave violent entertainment and news is a form of entertainment. Violence has not been eliminated; there’s always enough to fill the evening news.

Another reason is that as we care about more and more categories of violence, we become more sensitive to the violence that does occur. In the US there’s a campaign to stamp out bullying. Even 20 years ago, that wouldn’t have been violence, that would have been childhood.

We’re taught that the twentieth century was uniquely bloody. Is that false?

There were 28 mass atrocities in previous centuries that proportionally killed the same or greater percentages of the world’s population, such as the invasions of Tamerlane and Genghis Khan. Every time a dynasty collapsed in China there could be tens of millions of deaths.

Twentieth-century violence was state-run. You say that the creation of states helped reduce violence, but can’t it go too far the other way?

Exactly, tyranny and anarchy can both unleash a lot of violence. The world is, I think, muddling towards some kind of sweet spot between the two. Enough centralised violence to deter violent chaos but not so much that the government becomes as much of a menace to the people as they were to each other.

What other factors reduce violence?

I mention several in my book. One is the theory of “gentle commerce”, that trade reduces violence between nations and individuals. There’s relatively little research within the psychology laboratory on this, perhaps because my profession doesn’t find commerce sexy enough, but there’s a growing body of political science evidence to support it. China is certainly significantly less violent since it opened up to trade.

If we can look forward to an even less violent future, what will our ancestors judge us harshly for, just as we shudder at cat-burning now?

Perhaps our treatment of animals in factory farms. I suspect too that the violence associated with the drug trade and the War on Drugs would be relieved by legalisation that brings it within the state’s monopoly of violence. Certainly that happened with the end of Prohibition.

Steven Pinker was speaking to Marc Sidwell. Pinker is the Johnstone Family professor of psychology at Harvard. His books include The Language Instinct and The Blank Slate. His new book The Better Angels of Our Nature is published by Allen Lane, £30.