The Parent Trap

In fact, neither scholars nor parents have always believed that parents matter. Sure, today rows upon rows of parent-advice books fill stores, parenting magazines clog newsstands, and new parents know the names Penelope Leach and T. Berry Brazelton better than they do their newborns'. But a leading tome on child development published in 1934 didn't even include a chapter on parents. It was only in the 1950s that researchers began to seek the causes of differences among children in the ways that parents raised them (time line). Now Harris is part of a growing backlash against the idea that parents can mold their child like Play-Doh.

With an impish wit and a chatty style, Harris spins a persuasive argument that the 1934 book got it right. Her starting point is behavioral genetics. This field examines how much of the differences between people reflect heredity, the genes they inherit from their parents. Over the years, researchers have concluded that variations in traits like impulsivity, aggression, thrill-seeking, neuroticism, intelligence, amiability and shyness are partly due to genes. "Partly" means anywhere from 20 to 70 percent. The other 30 to 80 percent reflects "environment." "Environment" means influences like an encounter with a bully, a best-friendship that lasts decades, an inspiring math teacher. It also includes, you'd think, how your parents reared you. But Harris argues that "environment" includes a parental contribution of precisely zero (unless you count Mom and Dad's decision about which neighborhood to live in, which we'll get to later). When she says parents don't "matter," she means they do not leave a lasting effect--into adulthood. (She accepts that how parents treat a child affects how that child behaves at home, as well as whether the grown child regards the parents with love, resentment or anger.)

To reach her parents-don't-matter conclusion, Harris first demolishes some truly lousy studies that have become part of the scientific canon. A lot of research, for instance, concludes that divorce puts kids at greater risk of academic failure and problem behavior like drug use and drinking. Other studies claim to show that parents who treat their kids with love and respect, and who get along well with others, have children who also have successful personal relationships. Yet neither sort of study "proves the power of nurture at all," Harris says emphatically. Why? They do not take into account genetics. Maybe the reason some parents are loving or competent or prone to divorce or whatever is genetic. After all, being impulsive and aggressive makes you more likely to divorce; both tendencies are partly genetic, so maybe you passed them on to your kids. Then it's their genes, and not seeing their parents' marriage fail, that explain the kids' troubles, Harris claims. And if being patient and agreeable makes you more likely to be a loving and patient parent, and if you pass that nice DNA to your kids, then again it is the genes and not the parenting that made the kids nice.

Do your own eyes tell you that being a just-right disciplinarian--not too strict, not too easy--teaches children limits and self-control? Not so fast. Harris points out that children, through their innate temperament, can elicit a particular parenting style. For example, a little hellion will likely make her parents first impatient and then angry and then resigned. It isn't parental anger and resignation that made the kid, say, a runaway and a dropout. Rather, the child's natural, genetic tendencies made her parents behave a certain way; those same tendencies made her a runaway and a dropout. Again, argues Harris, not the parents' fault. By this logic, of course, parents don't get credit, either. You think reading to your toddler made her an academic star? Uh-uh, says Harris. Maybe kids get read to more if they like to get read to. If so, liking books is also what makes them good in school, not listening to "Goodnight Moon."

Studies of twins seem to support Harris's demotion of parents. "[I]dentical twins reared in the same home," says Harris, ". . . are no more alike than identical twins separated in infancy and reared in different homes." Apparently, being reared by the same parents did nothing to increase twins' alikeness. Same with siblings. "[B]eing reared by the same parents [has] little or no effect on [their] adult personalities," writes Harris. "The genes they share can entirely account for any resemblances between them; there are no leftover similarities for the shared environment to explain." By "shared environment," she means things like parents' working outside the home, battling constantly, being dour or affectionate. A son might be a cold fish like Dad, or react against him and become a warm puppy. "If children can go either way, turning out like their parents or going in the opposite direction," says Harris, "then what you are saying is that parents have no predictable effects on their children. You are saying that this parenting style does not produce this trait in the adult."

What Harris offers in place of this "nurture assumption" is the idea that peer groups teach children how to behave out in the world. A second-grade girl identifies with second-grade girls and adopts the behavioral norms of that group. Kids model themselves on other kids, "taking on [the group's] attitudes, behaviors, speech, and styles of dress and adornment," Harris says. Later, a child gravitates toward the studious kids or the mischief makers or whomever. Because people try to become more similar to members of their group and more distinct from members of other groups, innate differences get magnified. The jock becomes jockier, the good student more studious. This all begins in elementary school. Harris's bottom line: "The world that children share with their peers determines the sort of people they will be when they grow up."