For most humans living today, it's hard to imagine life without written language, governments and large-scale agriculture. But on the scale of human history, all of these are recent inventions. Until just 11,000 years ago, we lived in small groups, hunting, gathering and practicing simple farming. Tribal warfare was common, life spans were short and strangers were rarely encountered. While that lifestyle might seem to belong to the distant past, it is also the life that our bodies and our brains are adapted to, and it’s a life that some people around the world still live.

In his latest book, Jared Diamond, Pulitzer Prize-winning author of Guns, Germs, and Steel, argues that we also have a lot to learn from people who have continued to live as humans did for most of our history. The World Until Yesterday: What Can We Learn from Traditional Societies? (which comes out on Monday, December 31) takes readers around the world, from the New Guinea Highlands and the Amazon rainforest, to Africa’s Kalahari Desert and the Arctic Circle, where people still living the lives of our ancestors have lessons to teach us about how we might better live today.

What do you mean by “traditional societies?”

Traditional societies are small, a few dozen up to a few hundred people. They don’t have strong political leaders. Their membership is based particularly on relationships. They don’t deal with strangers; everybody knows everybody else. And they subsist either by hunting and gathering or by simple farming and herding, and today there still are traditional societies.

There are small societies in New Guinea and in the Amazon and in rural parts of modern nations like the United States. They contrast with what you could call “complex societies”—populous societies with thousands, millions or billions of people, with centralized state governments, where we encounter strangers every day. For example, here you and I are strangers, we’ve never encountered each other before, and we’re now talking. I’m not sending people out to kill you; you’re not sending people out to kill me. But, in a traditional society, encountering a stranger is frightening and dangerous.

Why is it important for us to learn about traditional societies?

We get ideas about how to bring up our children. We get ideas about how to have a better old age. We get ideas about how not to die of cancer, heart attacks and stroke. There’s a lot that’s admirable, and that we may envy when we hear about it. Certainly, when I was bringing up my own children, I did things based on what I learned in New Guinea that are not normal for Americans and Europeans.

What sort of childrearing practices did you adopt?

When out walking with the kids, we didn’t lead the kids. I would let my kids walk ahead. They would figure out what interested them and where they wanted to go, and I would stay 20 feet behind them so that I could run up quickly if they got into trouble.

What are some other things that we might want to consider adopting in our own lives?

Well, here’s a banal thing to adopt in our lives, but it’s very important: to think very clearly about dangers and hazards. If you ask Americans what they’re worried about, you’d probably hear people talk about terrorists and radiation and cancer-causing chemicals. Well, forget it, that’s not what’s going to kill most of us. A real hazard is cars, driving ourselves, or those other crazy drivers out there. Another example, especially when one gets older, is slipping in the shower. Each day I think, “Wow, now that I’ve taken a shower, I’ve done the most dangerous thing that I’m going to do today.”

You have described people in traditional societies as having a “constructive paranoia” about danger. I was surprised that they were less willing to take risks than we sometimes are.

There’s a reason for that. If I take a risk—for example, if I slip and break something—then I go to the hospital, and I’ll get fixed (unless I’m 85 years old, in which case my chances are not so good). Whereas if a New Guinean falls, there’s not a doctor who’s going to come bail you out. Instead, your foot may get mis-set in a way that’s going to leave you crippled for the rest of your life.

Is it possible for us to take away the wrong lessons from traditional societies?

Absolutely. Lots of people have the attitude that those who still live in traditional societies are barbarians and they should come into the modern world as fast as possible. The opposite view is that lots of people romanticize traditional societies and say, “Ah, they have the wisdom of the ages. They’re nice. They’re peaceful. We can learn from them.” There’s lots of wonderful stuff in them that we can learn from. But in fact, traditional societies do lots of horrible things, and thank God they’re over, such as strangling widows or putting their old people out on an iceberg. So we should neither romanticize traditional societies—there’s a lot that I think really is awful in them—nor should we despise them.

You show how there are lessons we can learn from the awful things, as well. I’m thinking especially about what tribal warfare teaches us.

This is something close to my own experience—secondhand, because my wife is a clinical psychologist, and one of her specialties is soldiers who come back from Iraq and Afghanistan. In our society, until a young man is 18, he is taught, “Thou shalt not kill.” Then, at age 18, you give him a gun and say, “Now you shall kill under certain circumstances.” The dilemma is that we raise our kids one way for years and then we tell them to behave in an opposite way, and that is very confusing.

Warfare is widespread among traditional societies. They never get taught at age two, “Thou shalt not kill.” Instead, they get taught, “For heaven sakes, do kill, do kill those evil people next door, and here’s the dead body of your uncle who just got killed. When you’re a little older, you’re going to take revenge.” There is a way you can apply the lesson, and that is to understand that we’ve acquired inhibitions about killing, but on the other hand, if somebody kills your buddy, boy, you certainly want revenge. We’re brought up to believe revenge is bad, it’s primitive, you should get beyond that. We need to realize that it’s perfectly natural to have feelings of revenge. We should not act on them, but we should not deny them, and we should work them out and express them in a safe form.

You’ve been traveling to New Guinea for many years. Does it sadden you to see people giving up traditional ways?

The bad outcomes are sad. When people move into the cities and can’t get a job because they had enough schooling not to want to be a farmer, but not to be able to get a good job, and as a result they turn to crime, yes, that’s sad. But it’s not sad for them to want to send their children to school and want to have enough to eat so they don’t starve to death. It’s not sad to see New Guineans not trapped in cycles of revenge warfare. When New Guineans see the Western world, there’s a lot that they want, and for good reason.

Should we be making any efforts to try and preserve these traditional cultures?

We can’t. People often ask me, “Jared, why don’t we Americans and Europeans just leave those uncontacted New Guinean and Amazonian societies alone and let them get on with their lives?” That reflects a fundamental misunderstanding about what goes on in New Guinea and the Amazon. It’s not that Westerners go in and change them against their will. It’s that they learn about what’s happening outside and there’s a lot that they want. Once they see a steel axe, they want a steel axe, not a stone axe. Once they see matches, they want matches, not a fire drill. Once they see a salt shaker, they want a shaker full of salt rather than going to monumental effort to make salt themselves. So it’s not that we go in and change them, it’s that once they learn what there is in the outside world, they seek that out and change themselves. That doesn’t mean, though, that traditional societies are going to die out. The challenge for a traditional society is to adopt some things from the outside world while retaining some features of the traditional society.