Why do we see these divisions? Why do we care about them so much? Why do we kill and die for them? This is the stuff of news headlines. How has a nation gone from peaceful coexistence to genocide? How does social status affect your health? Why are teenagers willing to kill themselves in hazing rituals in order to belong to a fraternity or social group? How do terrorists learn not to care about the lives of those they attack? gets at the heart of these profound questions by looking at their common root in human nature. Politics, culture, and economics play their parts, but its the human mind that makes them possible, and thats the focus of . Were not born with a map of human kinds; each person makes his own and learns to fight for it. This is a crucial subject that touches all of our lives in ways both large and small, obvious and subtle. Human-kind thinkingwhether beneficial or destructiveis part of human nature, as David Berrebys brilliant book reveals.