 I'm Salvatore Bobonas and today's lecture is Inequality and Health. Medicine may be a biological science, but public health is mostly a social science. And threats to public health are almost always in the end social problems, not scientific ones. The larger the scale you look at, the clearer it becomes that health problems are primarily social problems that are strongly shaped by inequalities in society as large. People don't die from inequality, but they do suffer from the ills of unequal societies. The worst of these ills may be the simple harshness of life in places where people just don't care for other people. Look, it's pretty obvious from a quick glance at the world that life expectancy is very unequally distributed. The life expectancy is highest in the dark blue countries in this map, in places like Western Europe, Australia, New Zealand, and Canada. And it is lowest, of course, in sub-Saharan Africa, and in conflict-ridden countries like Afghanistan. Much of this geographical distribution in good health, or at least living long, is related to countries' levels of income per capita. And so you'll see at low levels of income, countries below $5,000 or $10,000 per person per year, there's a steep rise in life expectancy as incomes rise. But among countries that have over $5,000 or $10,000 GDP per year in countries like Costa Rica and Russia, life expectancy doesn't really rise as income continues to rise. It's pretty flat. It rises slowly or not at all. In fact, beyond a bare minimum, income just doesn't seem to make people live longer. GDP per capita, the indicator that we use to measure income, is really a catch-all for the quality of society. And once you have a reasonably good quality society, it no longer matters for life expectancy. So consider for the example of Cuba. Cuba is one of those countries that is just at that point where increasing income no longer yields increasing levels of life expectancy. It has a GDP per capita of around $7,000 to $8,000 per year, right in that middle of that range of $5,000 to $10,000 per year. That means it's not a particularly rich country, but it does have very high life expectancy. 78 years compares pretty well with the developed countries of the world. Cuba would fit right in as a European or North American country with that level of life expectancy compared to other countries around the region. And it does better than anywhere else in the Caribbean, much better than Haiti, which is close by, but even much better than the Dominican Republic, which, unlike Haiti, is a reasonably developed country with no civil war. And yet, life expectancy in the Dominican Republic is four years lower than in Cuba. And really what it comes down to is that Cuba has a countrywide commitment to basic public health and to disaster preparedness that is shared by very few other countries. In fact, when we look at those developed countries, when we look at the richer countries of the world, life expectancy really isn't so much related to GDP per capita as it is related to inequality. The Gini coefficient is an indicator of inequality that runs from zero, perfect equality, to 100, total inequality. And the range in which we observe actual countries is between 20 and 70. And within that range, we do see a negative relationship. As inequality rises, life expectancy goes down. Now, it's not a strong relationship, but it is a statistically significant relationship. We can detect the effect. Among rich countries, that effect is even stronger. So among countries where GDP per capita is not the issue, these countries on this chart are all rich enough to afford food, hospitals, ambulance services, all the things that maintain life. Among rich countries, it's inequality that is the main driver of differences in life expectancy. Here, so this is a different measure of inequality. The ratio between the top 20% incomes to the bottom 20% incomes in society. But again, we see that higher inequality, a bigger distance between the top and bottom, is broadly associated with lower life expectancy. Now again, this graph may seem not to be absolutely clear. For example, some relatively low inequality countries do poorly on life expectancy. Some relatively high inequality countries do relatively well on life expectancy. Because life expectancy is really only one measure of health and well-being in society. When we look more broadly at a spectrum of measures of health and social problems, we see a much stronger correlation. So here we have a compendium of a dozen or so social and health problems simply combined into a single index in society. And this is from the Rook of Richard Wilkinson and Kate Pickett. And you can see that now countries line up very closely with higher inequality countries having more social problems and low inequality countries having fewer. And this is a broad spectrum approach that yields better results for two reasons. First, because inequality doesn't literally kill people. Inequality is a general indicator of how harsh society is. And the harshness of society, yes, it does have an impact on life expectancy. But it has an impact on all sorts of quality of life indicators. Mental illness, obesity, and believe it or not, in high inequality countries like the US, people are fatter than in low inequality countries like the Scandinavian countries, infant mortality, teenage births in high inequality countries. Teenagers are less likely to use birth control. Again, not something you'd immediately think of as something that would be correlated with inequality. After all, even poor people can afford birth control. But the harshness and the low quality of society leads to people not caring about whether or not they get into trouble in high school and have a baby at age 16. Of course, higher levels of criminality like homicide and imprisonment, there's worse educational outcomes in high inequality societies. And of course, there is much lower social mobility in high inequality societies. It's much harder to move from the bottom to the top for the children of the poor to get university educations. It's much harder than in relatively equal societies where moving from bottom to top is not such a big deal because the difference between bottom and top is much smaller. Now I said that this was the first reason why there's a clear correlation when we correlate these many indicators of social outcomes within equality. The second reason we see a stronger relationship when we use many indicators is that all of these indicators move in the same direction. Which means that if we add them up, we get a much stronger signal than if we look at each one individually. If you go to the data and you can go to the Equality Trust at the UK Equality Trust website run by Richard Wilkinson and his colleagues. And if you click on the spirit level section, you'll see detailed graphs for each of these indicators. And you'll see that each detailed graph has error of one kind or another, idiosyncratic results of one kind or another. But when you put it all together, the picture becomes, again, very clear. The simple reality is that people who live a hard knock life, people who have difficult, challenging lives, suffer the consequences. And these consequences are exacerbated by the contrast between their lives and others. So in the famous musical Annie set in 1933, depression era America, these orphan girls are living the rough life and they're going to have worse outcomes than other girls who are living with their families in stable environments who are well dressed and attending good schools. And that's just obvious, right? That people who have a harder life have worse outcomes and people who have a better life. But it's not just that difference. It's also the salience of that difference, the importance of that difference. The important society places on that difference. So these girls living in an orphanage in 1933 are isolated from society. They're not embedded in family structures. They're socially excluded. They're looked down upon. There's a big difference between being isolated in an orphanage run by someone who doesn't care about you. And being in high quality foster care with a loving family, right? So it's not just the fact of having a difficult life. It's the segregation. It's the discrimination. It's the separation between people who are living difficult lives and the rest of society. And we can perhaps see this very clearly with the example of homelessness. These are homeless shelters, not homeless shelters, homeless camps. People living homeless in the heart of Silicon Valley in California and the United States. Silicon Valley is one of the richest places on earth. Silicon Valley can easily afford to integrate people who can't afford houses into society. They could provide high quality, low cost public housing. After all, this is the richest place in the world. They could afford public housing. But in Silicon Valley, there's virtually no public housing. There's virtually no support for people who can't afford homes. And as a result, people live on the streets. Not only that, they live on the streets in very close proximity to people who have all the advantages of middle class society. People who have homes, who have cars, who eat in restaurants like this one in front of which this homeless tent is placed. So the crucial lesson that we learn from social epidemiology is that this separation, this harshness of society is actually more important than the literal harshness of life. After all, life is much harder in poor countries than in rich countries. Life is much harder in Cuba than it is in the United States. Yet, even though life is much harder in Cuba than in the United States, Cuba has similar or in many cases better indicators of health and social welfare than the United States does. And the reason is that society is less harsh, even if life may be difficult. And this is a key learning of social epidemiology. Social epidemiology is the study of illness and disease and how they are socially patterned. A major finding of social epidemiology is that people living at low income levels in countries that have lots of low income level don't suffer from social exclusion. While people living at low income levels in rich countries do suffer from social exclusion. So in a poor country where everybody is poor by the standards of the developed world, people who live in a simple house maybe without even running water can still maintain friendships with people around them. They're not segregated. They're not necessarily disrespected or targeted. In some places they are, but they don't have to be targeted by society, targeted by police, looked down upon. That is, they can just live the normal life of a normal person in the society in which they live. So even though they may be poor, they don't have to be socially excluded. On the other hand, big lifestyle gaps. In places where there's a big difference between rich and poor, there is social exclusion. So in high inequality countries, it's difficult, for example, for a bus driver to be friends with a heart surgeon. There's no rule against it. But the simple fact is that people don't socialize. What do they talk about? They have different experiences of the world. If the heart surgeon comes back from a shopping trip to Paris, well, how can he talk to his bus driver? Or how can they have a meaningful relationship when the bus driver may not be able to enjoy any kind of travel or when that's a whole different lifestyle than the bus driver might ever experience? Now in countries where there's a big gap, where the pay gap between bus drivers and heart surgeons is enormous, it's very difficult for people to share common experiences. But if the differences were relatively smaller, and again, here I'll use the example of Cuba. In Cuba where a doctor doesn't earn that much more than a bus driver, well, that doctor is able to socialize with the bus driver. She shares an experience of life with the bus driver. Her life is not so different in the end from the life of the bus driver. The larger the gap in lifestyle, the more strained the relationship. And inevitably, it's not the people at the top of the income distribution who end up socially excluded. It's the people at the bottom who end up socially excluded. Social exclusion in one form or another. There are all sorts of social exclusion in life. But social exclusion is one of the main determinants of the social gradient in health. The social gradient is the phenomenon that rich people or better off people or more advantaged people enjoy better health than poor people or disadvantaged people. That social gradient in health is universal, but it's not the same everywhere. So here is a social gradient in obesity in England. And you can see the social gradient in obesity is largest in London. In London, rich people, rich people's children, have only a 12 or 13 percent chance of being obese, while poor people's children have a 25 percent chance of being obese. Go across to the southwest of England, one of the more equal areas of England, and that gap between obesity, between rich and poor, rich people still have a level of obesity of 12 or 13 percent, while poor people have a level of obesity, children's obesity of around 20 percent. So although there's a gradient in every region of England, a slight gradient from rich to poor in levels of obesity, rich to poor, that gradient can either be very wide as it is in London or very narrow as it is in the southwest of England. Showing that perhaps even more graphically, here's a contrast between two areas, the northeast of England, which is relatively unequal in the southwest of England, which is relatively equal. And these are just mortality rates of different groups and societies. You'll see that equal or unequal, the mortality rate of higher managers and professionals, of the sorts of people who record YouTube videos, the sorts of people who are highly educated, who are privileged in society, are the same. I mean, we live anywhere in England, and the sorts of people who are high-income professionals have very similar levels of mortality. But when we look at people who are doing routine manual labor, people at the bottom of the status hierarchy, those in the more equal area of England have higher, much higher, I mean, twice the level of mortality as professionals. But people living in the more unequal area of England have three and a half times the level of mortality of professionals. And so there we see that the social gradient in health, we can see very graphically, can be either steep as it is in the northeast of England or can be shallow as it is in the southwest of England. Social gradient in health exists everywhere, but it can either be very extreme or very mild depending on social policies and inequality. And that's true everywhere in the world. It's not just true for England. This is an example of a percentage of children who are malnourished in different countries according to the social gradient, poorest versus richest. You can see in countries that have relatively good social policy, like Colombia, the gradient between richest and poorest is there, it's important, but it's much less steep than a difference in highly unequal societies like in Central America. In Central America, you can see this massive gradient between poorest and richest in malnourishment. Now notice that in Honduras, the richest are doing better than the richest in Colombia, even though Colombia is a much richer country than Honduras. In fact, in Colombia, the richer are a little worse and the poorer are much, much better. In Honduras, the poorer are much worse and the richer are doing a little better. So this huge social gradient in Honduras, a relatively slider social gradient in Colombia, and all of that is due to social context, not due to absolute resources. The pain of social exclusion can be made very visible when we look at historical examples when the social gradient has been turned upside down. And perhaps the most famous example of this is the tale of two cities, Charles Dickens' novel about the French Revolution. In the French Revolution, the poorest people took control of society and persecuted the richest. And in the novel, Dickens tells a whole fantastic story of how that affected a middle-class family of a doctor in France and his child. But we don't have to just turn to fiction to see how social hierarchies can be turned upside down, resulting in pain and social exclusion for the rich. We can look to much more recent history, for example, in China. During the cultural revolution years of the late 1960s and early 1970s, professionals of all kinds, teachers, doctors, managers at factories, were publicly humiliated. And this is a public shaming event at which teachers are being forced to stand and declare their crimes against communism, they declare their crime of feeling superior to others, while their students and ordinary people look on and yell abuses at them, criticize them. And in some famous examples, even beat them to death. Now, there were incidents where professionals in China were killed during the cultural revolution. There were instances of suicide during the cultural revolution, suicide of teachers, lawyers, professionals. But mostly what the cultural revolution illustrates is the trauma of being socially excluded at the bottom of society. And it illustrates that because almost all, and in English, all of our accounts of the cultural revolution come from that class of people who were used to being on top of society, but who were suddenly put at the bottom of society. And they found it incredibly unjust and traumatic to suddenly be publicly shamed. Yet of course, in ordinary societies, homeless people, manual laborers, the unemployed, are routinely shamed, are routinely looked down upon, are routinely harassed by police, are routinely called names in public. The cultural revolution in China showed educated elite people what it feels like to be a person on the bottom of society and they did not take it very well. In short, high levels of inequality generate widespread social exclusion and very steep social gradients in health. Now, in part, the social gradient in health is due to objective differences in the material conditions under which people live. If you have an unequal society, then rich people get better doctors and poor people get worse doctors. Rich people get better food and poor people get worse food. But we have a multitude of evidence to suggest that the subjective experience of being on the bottom of a high level of inequality, the subjective experience of being on the bottom of the social gradient is much more important for driving the health problems we see than simple lack of food or lack of medical care. It's very difficult to disentangle the precise causal pathways. But it seems scientifically clear and of course intuitively obvious that when it comes to people's quality of life, society matters. Key takeaways. First, higher inequality in a society tends to reduce the overall level of health broadly construed using multiple indicators. Second, social exclusion is a primary mechanism through which social inequality harms the health of society. And finally, the social gradient in health may be a universal phenomenon, but it can be steeper or shallower depending in large part on the levels of inequality in society. Thank you for listening. I'm Salvaturbo Bonus. You can find out more about me at my website, salvaturbobonus.com, where you can also sign up for my monthly Global Asian newsletter.