No Two Alike: Human Nature and Human Individuality

PUBLISHERS WEEKLY 21 NOV 2005

Why do identical twins who grow up together differ in personality? Harris attempts to solve that mystery. Her initial thesis in The Nurture Assumption: Why Children Turn Out the Way They Do is replaced here with a stronger, more detailed one based on evolutionary psychology. Reading this book is akin to working your way through a mystery novel complete with periodic references to Sherlock Holmes. And Harris has a knack for interspersing scientific and research-laden text with personal anecdotes. Initially, she refutes five red herring theories of personality differences, including differences in environment and gene-environment interactions. Eventually, Harris presents her own theory, starting from modular notions of the brain (as Steven Pinker puts it, "the mind is not a single organ but a system of organs"). Harris offers a three-systems theory of personality: there's the relationship system, the socialization system and the status system. And while she admits her theory of personality isn't simple, it is thought provoking. Harris ties up the loose ends of the new theory, showing how the development of the three systems creates personality. Harris's writing is highly entertaining, which will help readers stick with her through the elaboration of a fairly complex theory. 12 b&w illus.