Is social inequality merely something to be ashamed of, or does it bring ruin upon a society? I just finished reading a book review of The Spirit Level: Why More Equal Societies Almost Always Do Better (2009). This book by Richard Wilkinson and Kate Pickett was reviewed in the April 30, 2009 edition of Nature (available online only to subscribers). The reviewer was Michael Sargent, a developmental biologist. The Wilkinson/Pickett book explores the social consequences of income inequality.

Using statistics from reputable independent sources, they compare indices of health and social development in 23 of the world's richest nations and in the individual US states. Their striking conclusion is that the societies that do best for their citizens are those with the narrowest income differentials-such as Japan and the Nordic countries and the US state of New Hampshire. The most unequal-the United States as a whole, the United Kingdom and Portugal do worst. Many measures of the quality of life, including life expectancy, are correlated with the degree of economic equality in each country.

Here's the elephant in the political room: there is nothing in the Republican platform to address this damage being inflicted upon society. Quite the opposite: the Republican platform has continually stoke a wild unregulated capitalistic engine that disproportionately rewards some at the expense of others. What kind of damage is caused by this widespread disparity? You name it:

Problems such as mental illness, obesity, cardiovascular disease, unwillingness to engage with education, misuse of illegal and prescription drugs, teenage pregnancy, lack of social mobility and neglect of child welfare increase with greater inequality. Violence, from murder to the bullying of children in school follows the same pattern. These trends are tied up with the issues of trust: the authors chart a profound decline in trust and United States from the 1960s to the present, which matches rising inequality during the long Republican ascendancy.

The authors go so far as to suggest a local hardwired biological mechanism: neuroendocrinological stress. The perception that others are reveling in the good life at one's expense undermines self-esteem and releases the hormone cortisol which causes stress, accompanied by high blood pressure and high blood sugar levels. The cortisol overwhelms hormones, such as oxytocin, that are critical for trust-building. The damaging effect of long-term cortisol has been well-studied and established in other animals. In some experiments, monkeys that were chronically shoved to the bottom of a wide social hierarchy "are more inclined to self medicate with cocaine, if given the opportunity." This article give me yet more evidence that we would be often better off to relinquish much of our judgmentalism and to reconceptualize morality as an aspect of ecology.