The relationship between wealth inequality and health outcomes and social problems has been known to researchers for some time, but only more recently to the public at large. If at first the idea was that rich countries had better measures of health and social problems, it became apparent that this wasn’t the case. Consider this diagram of average incomes to an index of health and social problems in developed countries in the Western world. (These diagrams all come from Wilkinson & Pickett, The Spirit Level, 2009, or from the associated website.)
There’s clearly no pattern here, nothing to indicate that some rich countries, such as the US, do better than relatively poor ones, such as Portugal—which they very clearly don’t.
Now, look at the income distributions in these countries:
It’s clear here that there are very wide variations in income inequality between countries. Some of them are a lot richer than others, but none is poor in absolute terms, no country is ‘developing’.
If we take the Health and Social Problems Index in the diagram above, and rather than using average income we take the inequality of incomes, measured as between the bottom 20% and the top 20% of earners we get something quite different:
The line up the graph measures ‘regression’; this is a statistical device showing the best fit between ‘Income inequality’ and ‘Index of Health and Social problems’. It is a measure of how likely the results are to be due to ‘chance’; here, the results here are very unlikely to be due to chance.
‘The index of health and social problems’ is a composite of all the factors shown on the right side of the graph; all are given equal weight. Note that some diseases are not measured directly; there is no association between breast and prostate cancer and Income inequality. Yet, increasing wealth inequality directly correlates with health and social problems.
Wilkinson and Pickett also compared this index with all 50 states of the USA, with similar results. They also presented graphs and further background information for each of the problems, finding similar patterns. There are occasional ‘outliers’—Finland has a higher homicide rate than would be otherwise expected. I say ‘expected’ because the position of any country on a graph of the individual problems will predict where that country will lie in respect of other problems. There are more such graphs on their website, here.
There was a mixed reception when The Spirit Level was published a few years. Some critics, mostly it seems from the ‘right’ questioned the data and the methodologies, those on the ‘left’ felt that their views were justified. Some of the data are a bit outdated now, though the general conclusions remain valid.
However, the diagrams do not explain just how income inequality could lead to such differences in health and social problems. There must be more going on, but what are these factors?
Recall the Whitehall I and II studies, where those in the lowest grades of the civil service had more heart attacks, and more of a whole range of problems. The researchers’ conclusions were that job stress and peoples’ sense of self-control over their work seemed to make the most difference. Low social status has a clear influence on physical health; but, more than this, there is a gradient across society, affecting all members. All these findings have been backed up by further research.
There is an interaction between the psyche, the mind, and the soma, the body. Multiple associations have been described, and the whole can seem really complex at times. A rise in anxiety levels has been observed in a long-term study of American college students; anxiety is often associated with depression. Likewise, there has been a rise in ‘self-esteem’, though this has two components. There is ‘healthy’ self-esteem, people with a generally positive attitude, the ability to make friends and accept criticism. But there is also ‘unhealthy’ self-esteem, people who are defensive and who deny any weakness, described as an attempt to maintain self-esteem in the face of threats. Such people react badly to criticism, and this ‘insecure’ self-esteem can be called narcissism. A rise in this narcissism has also been found in US college students, that is, in the young.
’Stress’ is a more complex, multifactorial concept, and is associated with ‘social-evaluative threats’ which damage self-esteem. Low social status, lack of friends and stress in early life (including as a foetus) are all sources of stress in general. Pride and its psychological opposite, shame have also been incriminated.
If the increases in these ‘bad’ psychological measures are increasing, and the evidence does strongly suggest that they are, how and why did this happen? It’s suggested that this is related to the fairly modern trend for communities to be disrupted; where once several generations of a family lived close to one another, people are more geographically mobile now, and perhaps lack a sense of community identity. Think of the difference between a nuclear family and a stem family; the latter lacks the wisdom gained from experience from senior members of the former, even if this isn’t always welcome. Greater inequality is also associated with greater distrust of other people, and there is certainly a replacement of judging people not by who they are, but by what they have—material ‘stuff’, and ‘conspicuous consumption’—and perceived ‘status’, based on possessions.
This is all getting overly complicated, and it is rather complicated, but the over-arching message is that greater income inequality in developed countries is clearly associated with greater levels of health and social problems, and these are strongly influenced by our psychological responses. I’m trying to present a ‘broad brush’ approach, to see the underlying patterns, even at the extent of ignoring some complexities.
The Nordic countries and Japan have low levels of income inequality and health and social problems. But their low income inequality comes from two different mechanisms. In Japan, there is a small gap between the gross pay of the lowest earners and the highest. In the Nordic countries, this relative equality is achieved by a combination of heavy taxation on high earners, and a generous range of benefits. It’s hardly a coincidence that the Nordic countries not only have high standards of living, but in global surveys, also have high levels of happiness. And the educational system in Finland is seen as the best in the world.
The conclusions of The Spirit Level have been repeated and expanded in several recent publications, listed on the website.
Finally, the authors of The Spirit Level originally considered calling it Evidence-based Politics.