By CAROL TAVRIS

THE NURTURE ASSUMPTION

Why Children Turn Out the Way They Do.

By Judith Rich Harris.

462 pp. New York:

The Free Press. $26.



s I was writing this review, two friends called to ask me about ''that book that says parents don't matter.'' Well, that's not what it says. What ''The Nurture Assumption'' does say about parents and children, however, warrants the lively controversy it began generating even before publication.

Judith Rich Harris was chucked out of graduate school at Harvard 38 years ago, on the grounds that she was unlikely to become a proper experimental psychologist. She never became an academic and instead turned her hand to writing textbooks in developmental psychology. From this bird's-eye vantage point, she began to question widespread belief in the ''nurture assumption -- the notion that parents are the most important part of a child's environment and can determine, to a large extent, how the child turns out.'' She believes that parents must share credit (or blame) with the child's own temperament and, most of all, with the child's peers. ''The world that children share with their peers is what shapes their behavior and modifies the characteristics they were born with,'' Harris writes, ''and hence determines the sort of people they will be when they grow up.''

The public may be forgiven for saying, ''Here we go again.'' One year we're told bonding is the key, the next that it's birth order. Wait, what really matters is stimulation. The first five years of life are the most important; no, the first three years; no, it's all over by the first year. Forget that: It's all genetics! Cancel those baby massage sessions!

What makes Harris's book important is that it puts all these theories into larger perspective, showing what each contributes and where it's flawed. Some critics may pounce on her for not having a Ph.D. or an academic position, and others will quarrel with the importance she places on peers and genes, but they cannot fault her scholarship. Harris is not generalizing from a single study that can be attacked on statistical grounds, or even from a single field; she draws on research from behavior genetics (the study of genetic contributions to personality), social psychology, child development, ethology, evolution and culture. Lively anecdotes about real children suffuse this book, but Harris never confuses anecdotes with data. The originality of ''The Nurture Assumption'' lies not in the studies she cites, but in the way she has reconfigured them to explain findings that have puzzled psychologists for years.

First, researchers have been unable to find any child-rearing practice that predicts children's personalities, achievements or problems outside the home. Parents don't have a single child-rearing style anyway, because how they treat their children depends largely on what the children are like. They are more permissive with easy children and more punitive with defiant ones.

Second, even when parents do treat their children the same way, the children turn out differently. The majority of children of troubled and even abusive parents are resilient and do not suffer lasting psychological damage. Conversely, many children of the kindest and most nurturing parents succumb to drugs, mental illness or gangs.

Third, there is no correlation -- zero -- between the personality traits of adopted children and their adoptive parents or other children in the home, as there should be if ''home environment'' had a strong influence.

Fourth, how children are raised -- in day care or at home, with one parent or two, with gay parents or straight ones, with an employed mom or one who stays home -- has little or no influence on children's personalities.

Finally, what parents do with and for their children affects children mainly when they are with their parents. For instance, mothers influence their children's play only while the children are playing with them; when the child is playing alone or with a playmate, it makes no difference what games were played with mom.

Most psychologists have done what anyone would do when faced with this astonishing, counterintuitive evidence -- they've tried to dismiss it. Yet eventually the most unlikely idea wins if it has the evidence to back it up. As Carole Wade, a behavioral scientist, puts it, trying to squeeze existing facts into an outdated theory is like trying to fit a double-sized sheet onto a queen-sized bed. One corner fits, but another pops out. You need a new sheet or a new bed.

''The Nurture Assumption'' is a new sheet, one that covers the discrepant facts. I don't agree with all the author's claims and interpretations; often she reaches too far to make her case -- throwing the parent out with the bath water, as it were. But such criticisms should not detract from her accomplishment, which is to give us a richer, more accurate portrait of how children develop than we've had from outdated Freudianism or piecemeal research.

The first problem with the nurture assumption is nature. The findings of behavior genetics show, incontrovertibly, that many personality traits and abilities have a genetic component. No news here; many others have reported this research, notably the psychologist Jerome Kagan in ''The Nature of the Child.'' But genes explain only about half of the variation in people's personalities and abilities. What's the other half?

Harris's brilliant stroke was to change the discussion from nature (genes) and nurture (parents) to its older version: heredity and environment. ''Environment'' is broader than nurture. Children, like adults, have two environments: their homes and their world outside the home; their behavior, like ours, changes depending on the situation they are in. Many parents know the eerie experience of having their child's teacher describe their child in terms they barely recognize (''my kid did what?''). Children who fight with their siblings may be placid with friends. They can be honest at home and deceitful at school, or vice versa. At home children learn how their parents want them to behave and what they can get away with; but, Harris shows, ''These patterns of behavior are not like albatrosses that we have to drag along with us wherever we go, all through our lives. We don't even drag them to nursery school.''

Harris has taken a factor, peers, that everyone acknowledges is important, but instead of treating it as a nuisance in children's socialization, she makes it a major player. Children are merciless in persecuting a kid who is different -- one who says ''Warshington'' instead of ''Washington,'' one who has a foreign accent or wears the wrong clothes. (Remember?) Parents have long lamented the apparent cruelty of children and the obsessive conformity of teen-agers, but, Harris argues, they have missed the point: children's attachment to their peer groups is not irrational, it's essential. It is evolution's way of seeing to it that kids bond with each other, fit in and survive. Identification with the peer group, not identification with the parent, is the key to human survival. That is why children have their own traditions, words, rules, games; their culture operates in opposition to adult rules. Their goal is not to become successful adults but successful children. Teen-agers want to excel as teen-agers, which means being unlike adults.

It has been difficult to tease apart the effects of parents and peers, Harris observes, because children's environments often duplicate parental values, language and customs. (Indeed, many parents see to it that they do.) To see what factors are strongest, therefore, we must look at situations in which these environments clash. For example, when parents value academic achievement and a student's peers do not, who wins? Typically, peers. Differences between black and white teen-agers in achievement have variously been attributed to genes or single mothers, but differences vanish when researchers control for the peer group: whether its members value achievement and expect to go to college, or regard academic success as a hopeless dream or sellout to ''white'' values.

Are there exceptions? Of course, and Harris anticipates them. Some children in anti-intellectual peer groups choose the lonely path of nerdy devotion to schoolwork. And some have the resources, from genes or parents, to resist peer pressure. But exceptions should not detract from the rule: that children, like adults, are oriented to their peers. Do you dress, think and behave more like others of your generation, your parents or the current crop of adolescents?

Harris writes beautifully, in a tone both persuasive and conversational. But many people are deeply invested, financially and emotionally, in the ''nurture assumption'' and won't give it up, I suspect, without a fight: the vast advice-to-parents industry and the ''guilty mother'' brigade, whose work fills our airwaves, books, magazines and newspapers; therapists who believe that our personalities and problems are created by unconscious dynamics, neurotic parents or childhood experiences; politicians elected on the claims that day care, divorce and working mothers are bad for children; people who want to blame their parents for everything that's wrong in their lives; and parents who understandably want credit for their efforts to raise good kids in tough times.

Others, however, may reject this book because of concerns about its potential misuses. If children ''naturally'' exclude ''outsiders,'' why should schools make any effort to integrate children of different ethnicities, sexes or abilities? Why should we pay for prenatal care or better schools if smart, resilient kids will turn out all right whatever we do, and troubled ones will be lost to deviant peer groups?

These concerns are especially important in our antichild culture, which already lags behind European nations in measures supporting children's health, education and universal day care. Some people may indeed try to use Harris's evidence to legitimize our national neglect of children. For those committed to the well-being of all children, however, here is information that can lead to better programs, ones that might actually work.

For example, Harris makes it clear why most bilingual education programs have failed: Children will speak the way their friends do. If other kids are speaking the language they hear at home, that's what they'll speak. If other kids speak English with a Spanish or Bostonian accent, they will acquire an accent too. If other kids are speaking a language they don't know, they'll learn it fast. Any program, bilingual or monolingual, that doesn't take into account the power of peers is doomed. Likewise, Harris shows why the costly programs designed to get teen-agers to avoid drugs, stay in school or abstain from sex have been such duds; they have been targeted to individual teen-agers or their parents.

The greatest fear surrounding Harris's book is that her message will somehow encourage the neglect or outright abuse of children. This concern reveals, perhaps, what a deeply antichild culture we are, for it assumes that we are nice to children only out of a desire to make them perfect replicas of ourselves -- and if we can't, we might as well abandon them. But if you realize you can't turn your shy child into an extrovert, does that mean you won't help her cope in scary new situations? Why should the good news that most children are resilient be construed in any way as an endorsement of neglecting their health or permitting adults to abuse them?

Harris believes that parents should treat children well for the reason they should be kind to their partners -- not in hopes of transforming their personalities or controlling their futures, but in hopes of remaining good friends for a lifetime. Parents matter, she says, primarily in determining the kind of relationship they will have with their children -- friendly or bitter, accepting or adversarial --and how their children feel about them.

Many readers will disagree with Harris's conclusions about the limited influence of parents. Everyone knows people who have spent untold hours with their shy, difficult or learning-disabled children -- genetic predispositions all -- and thereby helped their children succeed in their peer groups, school and life. And everyone has friends whose harsh, unforgiving or neglectful parents left wounds that still hurt, though these wounds might never be apparent on a personality test.

But it would be a shame if readers get so focused on the degree to which parents matter that they overlook Harris's most important message, which is that parents aren't all that matter. This news should reassure people who blame themselves, as society blames them, for their children's problems with drugs, mental illness or violence. But it may panic parents who are consumed by a near-hysterical passion to control their children's personalities, abilities, careers, safety, eating habits -- and inspire them to start feverishly trying to micromanage their children's peer groups as well. Forget it. ''The idea that we can make our children turn out any way we want is an illusion,'' Harris writes. ''You can neither perfect them nor ruin them. They are not yours to perfect or ruin: they belong to tomorrow.'' In the current cacophony of advice to parents, could any words be wiser?

Carol Tavris, a social psychologist, is the co-author of three textbooks in psychology.