Richard Wilkinson and Kate Pickett's The Spirit Level: Why Equality is Better for Everyone is the most influential and talked-about book on society in the last decade - now updated with a new chapter on the controversy the book has ignited.

Why do we mistrust people more in the UK than in Japan? Why do Americans have higher rates of teenage pregnancy than the French? What makes the Swedish thinner than the Australians? The answer: inequality.

This groundbreaking book, based on years of research, provides hard evidence to show: How almost everything - from life expectancy to mental illness, violence to illiteracy - is affected not by how wealthy a society is, but how equal it is. That societies with a bigger gap between rich and poor are bad for everyone in them - including the well-off. How we can find positive solutions and move towards a happier, fairer future. Urgent, provocative and genuinely uplifting, The Spirit Level has been heralded as providing a new way of thinking about ourselves and our communities, and could change the way you see the world.