This groundbreaking book, a Pulitzer Prize finalist and New York Times notable pick, rattled the psychological establishment when it was first published in 1998 by claiming that parents have little impact on their children's development. In this tenth anniversary edition of The Nurture Assumption , Judith Harris has updated material throughout and provided a fresh introduction. Combining insights from psychology, sociology, anthropology, primatology, and evolutionary biology, she explains how and why the tendency of children to take cues from their peers works to their evolutionary advantage. This electrifying book explodes many of our unquestioned beliefs about children and parents and gives us a radically new view of childhood. "A graceful, lucid, and utterly persuasive assault on virtually every tenet of child development." -- Malcolm Gladwell, The New Yorker "Ten years on, this book stands as a landmark in the history of psychology -- and a cracking good read." -- Steven Pinker Judith Rich Harris is the author of No Two Alike: Human Nature and Human Individuality . A former writer of college textbooks, Harris is a recipient of a George A. Miller award, given to the author of an outstanding article in psychology. She is an independent investigator and theoretician whose interests include evolutionary psychology, social psychology, developmental psychology, and behavioral genetics. Chapter 1: "NURTURE" IS NOT THE SAME AS "ENVIRONMENT" Heredity and environment. They are the yin and yang, the Adam and Eve, the Mom and Pop of pop psychology. Even in high school I knew enough about the subject to inform my parents, when they yelled at me, that if they didn't like the way I was turning out they had no one to blame but themselves: they had provided both my heredity and my environment. "Heredity and environment" -- that's what we called them back then. Nowadays they are more often referred to as "nature and nurture." Powerful as they were under the names they were born with, they are yet more powerful under their alliterative aliases. Nature and nurture rule. Everyone knows it, no one questions it: nature and nurture are the movers and shapers. They made us what we are today and will determine what our children will be tomorrow. In an article in the January 1998 issue of Wired, a science journalist muses about the day -- twenty? fifty? a hundred years from now? -- when parents will be able to shop for their children's genes as easily as today they shop for their jeans. "Genotype choice," the journalist calls it. Would you like a girl or a boy? Curly hair or straight? A whiz at math or a winner of spelling bees? "It would give parents a real power over the sort of people their children will turn out to be," he says. Then he adds, "But parents have that power already, to a large degree." Parents already have power over the sort of people their children will turn out to be, says the journalist. He means, because parents provide the environment. The nurture. No one questions it because it seems self-evident. The two things that determine what sort of people your children will turn out to be are nature -- their genes -- and nurture -- the way you bring them up. That is what you believe and it also happens to be what the professor of psychology believes. A happy coincidence that is not to be taken for granted, because in most sciences the expert thinks one thing and the ordinary citizen -- the one who used to be called "the man on the street" -- thinks something else. But on this the professor and the person ahead of you on the checkout line agree: nature and nurture rule. Nature gives parents a baby; the end result depends on how they nurture it. Good nurturing can make up for many of nature's mistakes; lack of nurturing can trash nature's best efforts. That is what I used to think too, before I changed my mind. What I changed my mind about was nurture, not environment. This is not going to be one of those books that says everything is genetic; it isn't. The environment is just as important as the genes. The things children experience while they are growing up are just as important as the things they are born with. What I changed my mind about was whether "nurture" is really a synonym for "environment." Using it as a synonym for environment, I realized, is begging the question. "Nurture" is not a neutral word: it carries baggage. Its literal meaning is "to take care of" or "to rear"; it comes from the same Latin root that gave us nourish and nurse (in the sense of "breast-feed"). The use of "nurture" as a synonym for "environment" is based on the assumption that what influences children's development, apart from their genes, is the way their parents bring them up. I call this the nurture assumption. Only after rearing two children of my own and coauthoring three editions of a college textbook on child development did I begin to question this assumption. Only recently did I come to the con