This is a book with a big idea, big enough to change political thinking, and bigger than its authors at first intended. The problem they originally set out to solve was why health within a population gets progressively worse further down the social scale; they estimate that together they have clocked up more than 50 person-years gathering information from research teams across the globe.
Their eureka moment came when they thought of putting the medical data alongside figures showing the extent of economic inequality within each country. They say modestly that since dependable statistics both on health and on income distribution are internationally available, it was only a matter of time before someone put the two together. All the same, they are the first to have done so.
Their book charts the level of health and social problems as many as they could find reliable figures for against the level of income inequality in 20 of the world's richest nations, and in each of the 50 United States. They allocate a brief chapter to each problem, supplying graphs that display the evidence starkly and unarguably. What they find is that, in states and countries where there is a big gap between the incomes of rich and poor, mental illness, drug and alcohol abuse, obesity and teenage pregnancy are more common, the homicide rate is higher, life expectancy is shorter, and children's educational performance and literacy scores are worse. The Scandinavian countries and Japan consistently come at the positive end of this spectrum. They have the smallest differences between higher and lower incomes, and the best record of psycho-social health. The countries with the widest gulf between rich and poor, and the highest incidence of most health and social problems, are Britain, America and Portugal.
Richard Wilkinson, a professor of medical epidemiology at Nottingham University, and Kate Pickett, a lecturer in epidemiology at York University, emphasise that it is not only the poor who suffer from the effects of inequality, but the majority of the population. For example, rates of mental illness are five times higher across the whole population in the most unequal than in the least unequal societies in their survey. One explanation, they suggest, is that inequality increases stress right across society, not just among the least advantaged. Much research has been done on the stress hormone cortisol, which can be measured in saliva or blood, and it emerges that chronic stress affects the neural system and in turn the immune system. When stressed, we are more prone to depression and anxiety, and more likely to develop a host of bodily ills including heart disease, obesity, drug addiction, liability to infection and rapid ageing.
Societies where incomes are relatively equal have low levels of stress and high levels of trust, so that people feel secure and see others as co-operative. In unequal societies, by contrast, the rich suffer from fear of the poor, while those lower down the social order experience status anxiety, looking upon those who are more successful with bitterness and upon themselves with shame. In the 1980s and 1990s, when inequality was rapidly rising in Britain and America, the rich bought homesecurity systems, and started to drive 4x4s with names such as Defender and Crossfire, reflecting a need to intimidate attackers. Meanwhile the poor grew obese on comfort foods and took more legal and illegal drugs. In 2005, doctors in England alone wrote 29m prescriptions for antidepressants, costing the NHS 400m.
Status anxiety and how we respond to it are basic, it seems, to our animal natures. In an experiment with macaque monkeys, the animals were housed in groups, and the social hierarchies that developed among them were observed. Then the monkeys were taught to administer cocaine to themselves by pressing a lever. The dominant monkeys in each group were relatively abstemious, but the subordinate monkeys took a lot of cocaine to medicate themselves against the pain of low social status. In a similar experiment, high-status monkeys from different groups were housed together, so that some of them became low status. The downwardly mobile monkeys accumulated abdominal fat and developed a rapid build-up of atherosclerosis in their arteries, just like humans.
The different social problems that stem from income inequality often, Wilkinson and Pickett show, form circuits or spirals. Babies born to teenage mothers are at greater risk, as they grow up, of educational failure, juvenile crime, and becoming teenage parents themselves. In societies with greater income inequality, more people are sent to prison, and less is spent on education and welfare. In Britain the prison population has doubled since 1990; in America it has quadrupled since the late 1970s. American states with a wide gap between rich and poor are likelier to retain the death penalty, and to hand out long sentences for minor crimes. In California in 2004, there were 360 people serving life sentences for shoplifting. California has built only one new college since 1984, but 21 new prisons. Whereas societies with high income differentials are exceptionally punitive, in Japan imprisonment rates are low and offenders who confess their crimes and express a desire to reform are generally trusted to do so by the judiciary and the public.
The authors method is objective and scientific, so that the human distress behind their statistics mostly remains hidden. But when they quote from interviews conducted by social researchers, passion and resentment flood into their book. A working-class man in Rotherham tells of the shame he felt having to sit next to a middle-class woman ( this stuck-up cow, you know, slim, attractive ); how he felt overweight and started sweating; how he imagined her thinking, listen, low-life, don t even come near me. We pay to get away from scum like you . In half a page it tells you more about the pain of inequality than any play or novel could.
It might be said that The Spirit Level merely formulates what everyone has always felt. Western European utopias have almost all been egalitarian. Polls in Britain over the past 20 years show that the proportion of the population who think income differences too big is on average 80%. But what is new about their book, the authors insist, is that it turns personal intuitions into publicly demonstrable facts. With the evidence they have supplied, politicians now have a chance to do genuine good . By reducing income inequality, they can improve the health and wellbeing of the whole population. How this should be effected, Wilkinson and Pickett do not think it is their job to say, but increasing top tax rates or legislating to limit maximum pay are possibilities they suggest. They warn, though, that short-term remedies like this could be reversed by a change of government, and that we need to find ways of rooting greater equality more deeply in our society. This is their book's mission, and they have set up a not-for-profit trust (equalitytrust.org) to make the evidence they set out better known. One illusion that, cheeringly, they hope to dispel is that the super-rich are some kind of asset we should all cherish, rather than, from the viewpoint of social health, the equivalent of the seven plagues of Egypt.
- John Carey