"The Spirit Level: Why More Equal Societies Almost Always Do Better" is a book by Richard Wilkinson and Kate Pickett that explores the relationship between income inequality and various social outcomes. The authors argue that more equal societies tend to have better health, lower crime rates, and improved education, suggesting that equality fosters a stronger sense of community and well-being. The book presents data from multiple countries, demonstrating that societies with smaller income gaps experience fewer social problems. By highlighting the negative effects of inequality, Wilkinson and Pickett advocate for policies that promote economic equality as a means to enhance overall societal health and prosperity.