Before I started writing this blog, I read an interesting book called The Spirit Level: Why Greater Equality Makes Societies Stronger by Kate Pickett and Richard Wilkinson. It occurred to me the other day, when I found myself making use of some of the book’s statistics in an argument, that I have not yet shared its findings with blog readers. This struck me as something of a massive oversight–the book establishes statistical relationships linking numerous social pathologies to income inequality, and it even shows that inequality has a much stronger influence on these pathologies than raw wealth in absolute terms.

Before we begin in earnest, a brief note–there are places in the book where the authors make their argument a bit stridently (David Runciman has an excellent review highlighting the primary issue–the authors sometimes claim that inequality is bad for everyone when their research is only strong enough to conclusively claim that it is bad for societies on average). That said, the statistics they use are quite sound and meet academic standards–if you find yourself skeptical of any of the claims in this post, I urge you to read their online FAQ, where they respond to many of the common counterarguments anti-egalitarians have tried to make in response to their work.

To be clear, the authors measure inequality by comparing the income of the top quintile (20%) with that of the bottom quintile. The other statistics are sourced from peer-reviewed academic research, and the original sources can be found at their website.

With that out of the way, let’s get started. Our three ways are:

Healthcare–inequality results in worse health outcomes on average across a variety of metrics. Education–inequality results in worse child and educational outcomes on average across a variety of metrics. Crime–inequality results in higher homicide and incarceration rates.

Let’s discuss each in turn.

Healthcare

When inequality is higher, more infants die on average:

More unequal societies also suffer higher rates of mental illness:

The same goes for drug abuse:

And obesity:

There is disagreement over how inequality leads to health problems–the most common explanation offered is that relative inequality causes people to feel marginalized and alienated from society. It also makes social interactions more contentious, as people are made more aware of the social hierarchy and their place in it. Together, these things increase stress and anxiety, worsening mental, cardiovascular, and immune health directly and pushing people to seek potentially harmful coping mechanisms.

Education

Inequality has negative effects on children’s well-being (a composite statistic devised by UNICEF which takes into a variety of things–you can read about how it is calculated here):

Students do worse on standardized tests in unequal societies:

Unequal societies also see higher rates of teenage pregnancy:

And social mobility is significantly lower in unequal societies:

Here the causal mechanism is more straightforward–affluent parents often use their resources to give their children a variety of advantages that poorer children don’t have (time and attention, private schooling, summer experiences, etc.). This often causes poor students to perform poorly, and that means they often end up in the same economic position as their parents. Their children go on to have the same disadvantages, perpetuation a cycle of poverty.

Crime

Unequal societies have higher homicide rates:

And unequal societies imprison more of their citizens:

Here both the health and education causes come into play–because more people are mentally ill or feel alienated or marginalized, they are more likely to commit crimes, because more people have been denied education and work opportunities, they have fewer alternative legitimate courses of action available to them. These factors cause people to lash out more often, sometimes violently (see the recent Baltimore riots, for instance).

Inequality persists in part because so many people presume that only absolute poverty matters–that poverty is only a serious social concern when people are without food, shelter, or other such things. In political theory terms, we often call such people “sufficientarians”–they believe that justice is achieved if everyone achieves some minimal standard of sufficiency, regardless of how unequal the society may be as a whole. The Spirit Level helps us see why sufficientarianism is not sufficient–even if our society’s poor have the basics of life, inequality will still lead to feelings of inferiority, alienation, marginalization, and hostility. It will still give some young people opportunities that are denied to others. These things will produce negative social pathologies even if poor families are at the minimal sufficiency standard, and in many rich countries some people are not even that well off–even today, there are significant numbers hungry and homeless people living in highly developed countries.

We continue to see no change because people are unaware of The Spirit Level statistics and because people are too quick to blame the poor for the problems. Right wingers argue that poor people can overcome their sense of inferiority, alienation, or lack of opportunity by working harder. They insist that it’s not about the cards you’re dealt, but what you do with them that counts. This emphasis on the individual is naive and unrealistic. People are not healthier, better educated, and less likely to go to prison in Norway or Japan because they are harder working or more virtuous but because of systems of social policies designed to promote well-being and social cohesion. More equal societies recognize that when individuals under-perform, it is not because those individuals are defective–it’s because the societies are. They move resources, opportunities, and incentives around to produce better behavior. They don’t stand around waiting for individuals to transcend their own socioeconomic backgrounds–they make better backgrounds in the first place.

That’s what we should all be trying to do.