[Edit: This data seems to underestimate the violent death tolls in state societies. I think the general thesis is still valid but the data I used in this article should be taken very skeptically.]

Beside not dying of infectious disease my favorite thing about living in the 21st century is the fact I live in an era of unprecedented world peace. For most of human history, people didn't live in civilizations. For 90% of Homo sapiens existence, everyone lived as hunter-gatherers, pastoralists, or just small-scale farmers. Primitive societies are violent.

A few of primitive societies stand out as having relatively less violence, particularly the Eskimos and the !Kung. The Eskimos live in the Arctic tundra. The !Kung live in the Kalahari desert. They have so little violence because there is so little to fight over.

Most people live in places with high population densities. Places with lots of food can support larger populations. I suspect that, prior to civilization, most people lived in the most plentiful regions like modern New Guinea. In The World Until Yesterday, Jared Diamond writes about how in New Guinea, entire tribes would commit regular genocide against each other.

The !Kung and the Eskimos were paragons of nonviolence by the standards of primitive societies. Yet the 20th century (which included the Russo-Japanese War, World War I, World War II, the Armenian Genocide, the Chinese Civil War, the Korean War, the Vietnam War, the Soviet-Afghan War and many other conflicts) had a fraction of the per capita violent deaths of the !Kung and the Eskimos.

I was surprised to discover that conflict death rate went up by an order of magnitude between the Colombian Exchange and the modern era. (The chart uses a log scale.) But even at its height, civilization's per capita violent death rate was a fraction of the most peaceful primitive societies we have numbers for.

If we lived with the violent death rate of the early 20th century then we would be fortunate. Global violence today is even lower than it was in the early 20th century.

World War Two was the biggest conflict in human history. It ended in 1945. Let's pessimistically cherry-pick our data by examining only 1947 and later. The violent death rate still goes down over time.