Intelligence: A Very Short Introduction describes what psychologists have discovered about how and why people differ in their thinking powers. Drawing on large-scale data, it considers how many types of intelligence there are and how intelligence changes with age. It also tackles some of the most burning questions surrounding intelligence, such as whether larger brains are cleverer, and how genes and environments contribute to people’s intelligence differences. It considers the new field of cognitive epidemiology, which draws links between intelligence and better health, less illness, and longer life, and asks whether intelligence is increasing. In this new edition, the controversial question of whether men and women differ in intelligence is also addressed.