We live in a world of deep inequality, and the gap between the rich and the poor is widening. We in the rich world generally agree that this is a problem we ought to help fix—but that the real beneficiaries will be the billions of people living in poverty. After all, inequality has little impact on the lives of those who find themselves on top of the pile. Right?

Not exactly, says British epidemiologist Richard Wilkinson.

For decades, Wilkinson has studied why some societies are healthier than others. He found that what the healthiest societies have in common is not that they have more—more income, more education, or more wealth—but that what they have is more equitably shared. 

In fact, it turns out that not only disease, but a whole host of social problems ranging from mental illness to drug use are worse in unequal societies. In his latest book, The Spirit Level: Why More Equal Societies Almost Always Do Better, co-written with Kate Pickett, Wilkinson details the pernicious effects that inequality has on societies: eroding trust, increasing anxiety and illness, encouraging excessive consumption.

The good news is that increased equality has the opposite effect: statistics show that communities without large gaps between rich and poor are more resilient and their members live longer, happier lives. 

YES! Magazine web editor Brooke Jarvis sat down with Richard Wilkinson to discuss the surprising importance of equality—and the best ways to build it.

Brooke: You've studied the impact of inequality on public health for a long time. Did any of your recent findings surprise you?

Richard: Oh, all of them. In fact, the relationship is weaker for health than for many other problems—we looked at life expectancy, mental illness, teen birthrates, violence, the percent of populations in prison, and drug use. They were all not just a little bit worse, but much worse, in more unequal countries. If I'd known how strong those connections would be, I would have looked for them a decade earlier. In fact, I'm still surprised that no one did look at them earlier.

There's nothing complicated in what we've done. Epidemiologists and people working in public health have been doing this work for some time, not only controlling for relative poverty, but for all the income levels within, for instance, an American state. So once you know the relationship between income and death rates, for example, you should be able to predict what a state's death rate will be. Actually, though, that doesn't produce a good prediction; what matters aren't the incomes themselves but how unequal they are. If you're a more unequal state, the same level of income produces a higher death rate.

In fact, in more unequal societies, these problems aren't higher by ten or twenty percent. There are perhaps eight times the number of teenage births per capita, ten times the homicide rate, three times the rate of mental illness. Huge differences. If social mobility were a perfect sorting system and everyone was sorted by ability, that wouldn't make the number of problems in the society greater. It wouldn't change the overall IQ of the population; it would just change the social distribution of IQ. We know from the findings that it's the status divisions themselves that create the problems. We're not making a great leap to say that this is causal. We, I think, show that it's almost impossible to find any other consistent explanation.

Brooke: It seems possible that this link hasn't been explored because we're so used to thinking of these problems as linked to poverty. To find out that they're tied not to the level of income but to the stratification of income—it's sort of an unexpected conclusion.

Richard: We show that these problems aren't affected by rich countries getting still richer. There are problems that we think of as problems of poverty because they're in the poorest areas of society, but a country like the U.S. can be twice as rich as Greece, Portugal, or Israel—the poorer of the rich, developed countries we look at—and the problems are no better even though Americans are able to buy twice as much of everything as the poorer developed societies. That doesn't make any difference; it's only the gaps between us that matter now. And that's really quite a striking thing to learn about ourselves and the effects of the social structure on us.

Brooke: How does thinking about these problems in terms of inequality rather than poverty change how we grapple with them?

Richard: I think people have been worried by the scale of social problems in our societies—feeling that though we're materially very successful, a lot of stuff is going wrong, and we don't know why. The media are always full of these social problems, and they blame parents or teachers or lack of religion or whatever. It makes an important difference to people to have an analysis that really fits, not only in a sort of academic way, but also that fits intuitions that people have had. People have intuited for hundreds of years that inequality was divisive and socially corrosive. In a way, that's all the data shows. It shows that that intuition is much truer than any of us expected.

Brooke: Your findings related to crime and imprisonment rates seem to be particularly illustrative of the way inequality can lead to social corrosion.

If you grow up in an unequal society, your actual experience of human relationships is different. Your idea of human nature changes: you think of human beings as self-interested. 

Richard: We quote a prison psychiatrist who spent 25 years talking to really violent men, and he says he has yet to see an act of violence which was not caused by people feeling disrespected, humiliated, or like they've lost face. Those are the triggers to violence, and they're more intense in more unequal societies, where status competition is intensified and we're more sensitive about social judgments.

We also found very big differences in the proportion of the population that's in prison in different countries and American states. But the differences aren't driven by the amount of crime, they're driven by the fact that people in unequal societies have more punitive attitudes about crime. It may have to do with fear across classes, lack of trust, and lack of involvement in community life. If you've got to go to prison, go to prison in Japan or one of the Scandinavian countries. You might get some rehabilitation. If you go to prison in some of the more unequal countries, you are very likely to come out a good deal worse than you went in.

Brooke: When I first heard about your work, I expected the book to deal with the material impacts of inequality. But your focus is different.

Richard: Yes. This is about the psychosocial effects of inequality—the impact of living with anxiety about our feelings of superiority or inferiority. It's not the inferior housing that gives you heart disease, it's the stress, the hopelessness, the anxiety, the depression you feel around that. The psychosocial effects of inequality affect the quality of human relationships. Because we are social beings, it's the social environment and social relationships that are the most important stressors. For individuals, of course, if you're going to lose your home, or if you're terribly in debt, those can be more powerful stressors. But amongst the population as a whole, it looks as if these social factors are the biggest stressors because so many people are exposed to them.

Brooke: What psychological impact does living in an unequal society have on people who are at the top of the scale?

Richard: Status competition causes problems all the way up; we're all very sensitive to how we're judged. Think about Robert Frank's books Luxury Fever or Falling Behind, or the great French sociologist Bourdieu—they show how much of consumption is about status competition. People spend thousands of pounds on a handbag with the right labels to make statements about themselves. In more unequal countries, people are more likely to get into debt. They save less of their income and spend more. They work much longer hours—the most unequal countries work perhaps nine weeks longer in a year.

If you grow up in an unequal society, your actual experience of human relationships is different. Your idea of human nature changes. If you grow up in a consumerist society, you think of human beings as self-interested. In fact, consumerism is so powerful because we're so highly social. It's not that we actually have an overwhelming desire to accumulate property, it's that we're concerned with how we're seen all the time. So actually, we're misunderstanding consumerism. It's not material self-interest, it's that we're so sensitive. We experience ourselves through each other's eyes—and that's the reason for the labels and the clothes and the cars.

Brooke: What's the effect of inequality on the way we perceive our communities—and how does that perception affect how they function?

Richard: Inequality affects our ability to trust and our sense that we are part of a community. In a way, that is the fundamental mediator between inequality and most of these outcomes, through the damage it does to social relations. For instance, in more equal countries or more equal states, two-thirds of the population may feel they can trust others in general, whereas in the more unequal countries or states, it may drop as low as 15 percent or 25 percent.

Let me tell you what I think is perhaps at the very bottom of all this. If you think of almost any animal species, there is a huge potential for conflict amongst members of the same species, because they have all the same needs. They eat the same food stuffs, they need the same nesting sites, they value the same feeding grounds or territories, they compete for sexual partners. It was that recognition in human populations that made the political philosopher Thomas Hobbes in the 17th century say that human beings, without a sovereign power to keep the peace, would war against each other and have "nasty, brutish, and short" lives. Amongst monkeys, inequality takes the form of dominance hierarchies, based on power and coercion and privileged access to resources: "I get it first because I'm stronger, and I don't care if you're hungry." Human hierarchies are similar—it's why power, status, and wealth all go together at the top and why powerlessness, hunger, and poverty go together at the bottom.

But human beings also have the opposite potential. We can be the best source of love and learning and cooperation and assistance of every kind. In a sense, Hobbes was wrong about people in a state of nature. He was right about the potential for conflict, but people have avoided conflict through food sharing, gift exchange, and great social equality (for example, in hunter-gatherer societies). The gift in a sense is a symbol that you and I don't compete for the necessities of life. We don't need to fight each other for them. You feel a sense of indebtedness and you reciprocate the gift, which anthropologists have suggested is a sort of basic social contract. That symbolism is still really important: You invite your friends over, sit around the same table, and share food, the basic necessity of life. The symbolism is also there in religious services and communion—these things are very fundamental, very deep.

Inequality is a reflection of how strong hierarchies are, how much we share or how much we don't. It shows us which part of our potential we're developing. What game do I play? Have I got to fend for myself? Or have I got to get people to trust me and cooperate with me? Is my survival dependent on good relationships? Are you my rival? Are you going to steal from me? Have I got to keep what I've got, defend it? Or can we share? Human beings can do both. We've lived in the most egalitarian and the most awful, hierarchical, tyrannical societies. It's very interesting that we can measure how unequal societies are and how that can elicit more of certain kinds of behavior. 

Brooke: Once we become aware of the impact of inequality on all of these social ills, what do we do about it?

Richard: Countries seem to get their greater equality in quite different ways. Sweden, for example, uses the big government way: There are very big differences in earnings, which are redistributed through taxes and benefits. It has a large welfare state. Japan, on the other hand, has smaller income differences to start with, does much less redistribution, and doesn't have such high social expenditure. But both countries do very well—they're amongst the more equal countries and their health and social outcomes are very good.

What we've learned is that the real quality of life for all of us now depends on improving the social environment, and that we have a policy handle on how to do that. It's not that we all need to have more therapy to try and make us nicer people. Income distribution, an issue government or big corporations can do something about, really affects the psychosocial well-being of the whole society. But we can't just rely just on taxes and benefits to increase equality—the next government can undo them all at a stroke. We've got to get this structure of equality much more deeply embedded in our society. I think that means more economic democracy, or workplace democracy, of every kind. We're talking about friendly societies, mutual societies, employee ownership, employee representatives on the board, cooperatives—ways in which business is subjected to democratic influence. The bonus culture was only possible because the people at the top are not answerable to the employees at all.

Changing workplaces can have an enormous effect—not only is that where wealth is created, it's where income from production is initially divided up. It's also where we're most subjected to hierarchy and authority. Employee ownership turns a company into a community. The chief executive becomes answerable to employees. You might vote for your boss to have, I don't know, three times as much income as you—not 300 or 400 times more. Embedding greater equality and more democratic accountability in our institutions does much more than just changing income distribution or wealth distribution. And, a number of studies show that if you combine an even partial employee ownership, you get quite reliable increases in productivity. This is about how we work better together.

Brooke: Which is more important than ever, given that solving many of our major problems—global climate change, for example—will require unprecedented levels of cooperation.

Richard: Global warming, more than almost any other problem you can imagine, involves acting for the common good. It involves public spiritedness. And in more equal societies, where there's a stronger community life, less violence, and more trust, people give higher priority to the common good.

To test this out, we looked at the proportion of their income that countries give in foreign aid, and it's higher in the more equal countries. We looked at the proportion of different waste materials that are recycled, and that's higher in more equal countries. You don't do those things for yourself; they both depend on an idea of the greater good. An international survey of business leaders included the question, "How important do you think it is that your government abides by international environmental agreements?" In the more equal countries, business leaders rate that as more important than in the less equal countries. Inequality changes our perceptions—are you out for yourself, or do you recognize that we're in this together, that we've got to do these things for the common good?

This article was originally posted on Yes! Magazine.