Inequality has become a popular topic over the past decade. In books like Capital in the Twenty-First Century and Inequality and Instability, economists have warned that the growing income gap is spinning us back to strict 19th-century-style social hierarchies, where elites dominate everybody else, usually on the basis of inherited wealth.

What's usually overlooked in the conversation is how rising inequality can erode our health. This is a subject that Michael Marmot, a British physician and epidemiologist, knows a lot about. He's spent the past 40 years amassing a body of research that shows how inequality can be intrinsically bad for health outcomes — work he's collected in his new book, The Health Gap.



His findings are stunning. Marmot discovered that health and social status are often inextricably linked — even when you control for income, education, and other risk factors. This is true if you look at countries or at cities, or even drill down to the level smaller communities. And the implication of this research is that high levels of inequality can, on their own, make people sick.

Most famously, his Whitehall studies established a link between the relative rank of officers in the British civil service and their risk of disease and death. The higher an officer was ranked, the better his or her health. This was despite the fact that all civil servants were relatively well-off, with similar levels of education. Again, the stratification itself seemed to be the important factor.

Marmot calls the link between health and status "the social gradient in health." One possibility is that it's all related to a sense of control in one's life. People lower down in the social order feel like they have less control, which can lead to stress that then negatively impacts health.

Marmot has documented this social gradient in many other settings around the world. In London, life expectancy drops by one year for every stop heading east on the Jubilee metro line. In Baltimore's inner-city Upton neighborhood, men can expect to live until 63. In nearby Roland Park, an affluent social enclave with safer streets and better job prospects, that life expectancy rises to 83 — an incredible 20-year difference in a tiny geographic area.

Again and again, Marmot finds, health isn't just determined by how much you exercise or what your genes dictate; it's influenced by your social environment. I spoke with him recently by phone to find out more about whether there was anything we could do to address these imbalances.

Julia Belluz: One thing that comes up again and again in your book is that the US, despite having "the best health care system in the world," has terrible health and life expectancy outcomes compared with other wealthy countries. Why?



Michael Marmot: In many people's minds, inequality means poor health for the poor. That’s true — the poor do have poor health. But what the Whitehall study of British civil servants showed is that among people who aren’t poor and aren't rich either — among a population of employed people that excludes the poorest and richest — the higher the position in the hierarchy, the better the health, and it runs all the way from top to bottom. I called that the "social gradient in health."

The implications of that are rather profound. If you think about your readers, they probably think, "We’re not poor. We may not be well-off, but we’re not poorest or the richest, so this doesn't affect us." But the implication of the gradient is that they’re not free of this either. We’re all involved. All of us below the top have worse health than we would if we were at the top. The figures in Britain — which are not different from the US — say that someone with middle income has eight fewer years of healthy life than if he were at the top. Eight fewer years of healthy life means a decline in grip strength, mental function, and, eventually, a shorter life. The gradient is very profound and important.

JB: How do we know that social rank affects health outcomes and not the other way around?

MM: In this cause, correlation is causation. We’ve got good evidence, and it goes through the life course. It starts with early childhood development, continues with education, the likelihood of getting a job at all, the quality of work, and elsewhere, and the conditions for older people beyond working age. All of those impact health and the gradient in health. We’ve got strong evidence for that. It’s not just that you’ve got a correlation. Not only do we have evidence for the causal role, but we also have good evidence of what you can do to address it — which is why I wrote the book.

JB: Your work seems very pertinent given a new paper this week that showed that middle-aged white people are seeing increases in their death rate, while other age, racial, and ethnic groups in the US have seen only declines. The trend is clearly driven not only by health care but by social circumstances.



MM: If you look at the probability that a 15-year-old will not survive to 60 in the US, it's 13 percent. The US ranks 50th out of the 194 member countries of the World Health Organization on this measure, which means there are 49 other countries where a 15-year-old has a better survival chance than in the US. This is a country that spends far, far more on health care than any other country.

But this is not a health care issue. If you look at the causes of that premature mortality in the new study — it’s alcohol- and drug-related poisonings, suicide, other alcohol-related deaths, and external causes of death, and by that we mean homicide, violence, traffic pressures, and the like. So people don’t die of drug-related poisonings because of a lack of medical care; they die because they are taking drugs and/or committing suicide.

JB: Why do you think that's now happening in this group in particular?

MM: Well, I think you have to go back to early childhood. Countries that have bigger income inequalities, like the United States, in general have a steeper gradient in the quality of early childhood development. If you look at school performance, the US doesn't do as well as other countries. So the lower people's socioeconomic position, the worse their children do in standardized school tests. Going on from schools — in the US, the average earnings have not increased for over three decades.

So you start from worse early childhood development, worse performance in education, and then you come into adult life and think, "I'm going to be worse off than my parents. What I hoped to be able to give my children, I'm not sure I'm going to be able to." And then you think of the disinvestment from the public realm because of the relatively low tax rate in the US, the low degree of public spending — lower than any of the other rich countries. If you don't spend much money on improving communities and services, people's own income is not growing, the public sphere is under attack, people are under stress, and they turn to drugs and alcohol and suicide.

JB: What's the mechanism by which social rank and environment impact health?



MM: I'll contrast two pathways.

One is behavior. If you think about what most people think about when they think about public health, it's, "Don't smoke, eat sensibly, don't become overweight, be physically active, drink in moderation," and the like. That's all very important. But those behaviors tend to follow the social gradient: The lower people are in the social hierarchy, the more likely they are to be obese, to be less physically active, to smoke, to suffer the consequences of alcohol. The social environment impacts on health by conditioning people's behaviors. People under stress turn to alcohol, drugs, and violence because of that stress. It's not very mysterious that people do that.

The other way it affects health is through stress pathways. I talk about disempowerment: If you have little control of your life, you might smoke, drink, and so on, and you can’t do anything about the future anyway — so you might as well get drunk. There's evidence that these stress pathways related to disempowerment impact negatively on cardiovascular diseases, diabetes, and mental illness. That starts from the beginning of life.

JB: You've been called a "health Nazi" for advocating using the tax system and strengthening social programs to make fairer and healthier societies. While the evidence of health harm from inequality is clear, politically this is a tough message to get across — especially in the US, where individual rights and freedoms tend to trump social values.

MM: There has to be more of a focus on the social. We want to create the conditions for people to be empowered to take control of their lives. It’s not about trying to deprive individuals of control of their lives; it's trying to create conditions where they have it. I think the fact that the US ranks 50th on the chance of a young man surviving to 60 is reflecting disempowerment. It’s all very well to say it’s up to the individual. But to not get shot? To not feel suicidal? We’ve got an epidemic, and it's not due to a pill deficiency.

So it’s not just about improving health — it’s about improving society. Building a more cohesive society means equalizing life chances. This requires action at the community level, the national level, and the global level. That action needs to be through the life course. We have to create a more cohesive society where people can flourish.