Over the last few years I have surveyed people and their attitudes toward war. I ask people this question: "Do you think there will ever come a day when we stop fighting wars once and for all?” Over 90 percent of the people that I've surveyed say, “No, war is a permanent part of the human condition.  War is inevitable.”  And they often say that it’s because war is innate.  We’ve always fought and we always will because it’s part of human nature.

I was really distressed when Barack Obama was accepting the Nobel Peace Prize and during his speech he said something to the effect that since humans first appeared there has been lethal conflict.  We have always fought and therefore we should not expect to eradicate war in our lifetimes.  I thought that was—especially given the circumstances of his speech—an extraordinarily pessimistic thing to say. He was also making a scientific statement about the origins of war. So I set out to show people, drawing on the scientific literature on warfare, that we shouldn’t be fatalistic, that war actually is quite a recent cultural phenomenon.  

For instance, the theory that resource scarcity leads to war is contradicted by studies of some simple societies.  So there is a tribal society in the Amazon called the Yanomamo.  It’s very well known.  It was first studied by an anthropologist named Napoleon Chagnon beginning  in the 1960s and Chagnon wrote this book that became a huge bestseller called The Violent People that was published in the late 60s right during the Vietnam War.

The Yanomamo fight constantly and viciously.  They have these little villages that go out on raiding parties and spear each other and shoot arrows at each other and that of course leads to a feud.  What Chagnon has found is that there is an inverse correlation between the population density because the Yanomamo are spread over a very wide region of the Amazon.  So he has gone to different places and found that the more densely populated these tribal people are and the less food they have available, the less war there is.

So it’s exactly the opposite of what you would expect.  The really sparsely populated regions where there is plenty of game to go around, according to Chagnon, tend to be the most violent regions.  So Chagnon thinks that if anything this is because the more protein you have—this is one of his theories—the more well-fed you are, the more energy you have for this kind of sport. The Yanomamo see warfare as this: the more they’re struggling just to feed themselves the less energy they have for warfare.

Moreover, war is just not something that you see when you go back into human evolution. And culture, in fact, can also help us overcome this very destructive behavior.

In Their Own Words is recorded in Big Think's studio.