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, base ...