The Spirit Level is a data-based explanation of how preventable wealth inequality within countries and individual communities is to blame for many social health issues.

The citizens of most affluent nations tend to think of a nation's poverty as a direct cause of poor quality of life.

But even at the relative extremes of national wealth, it's income inequality - the gap in income within individual nations, cities, and communities - that is the true enemy of social health, wealth, and happiness.

Richard Wilkinson and Kate Pickett are British social epidemiologists and political activists, with Wilkinson having taught at the University of Nottingham and University College London.

In this book, the authors provide a statistical and logical argument for how large gaps in income cause our communities to be more anxious, hurried, depressed, and socially dysfunctional.