Book excerpt: This book turns the corner and finally provides a convincing explanation of IQ and human intelligence. It begins by rejecting some of the most basic assumptions that psychologists make about intelligence, including that intelligence should be defined by behavior. Instead, it argues that intelligence is about the ability to understand. It then uses recent scientific findings about the brain to show how changes in the brain lead to understanding. Readers will find that this book contains many revelations that will profoundly change their perception of how their own brain works. This book will also explore the startling implication of a sensitive period for developing intelligence, arguing that children can learn differently than adults. Anyone who is interested in how the brain works, why people differ in intelligence, and how a child can be a genius will want to read this book.