Book promotes concept of non-sexist child-rearing; Growing Up Free: Raising Your Child in the '80s, by Letty Cottin Pogrebin. New York: McGraw-Hill, $15.95.

One of the most durable markets in the book industry is "how to" books for those perpetually perplexed parents who, buffeted by the winds of social change, stagger and sometimes fall before the awesome task of child- rearing.

Letty Cottin Pogrebin's "Growing Up Free" is one of the most provocative and unorthodox books on this tireless subject to emerge from the feminist movement. Far from reassuring parents that they're doing fine, this voluminous tract (550 pages of text and 75 of notes) on non-sexist child-rearing challenges their most basic assumptions about bringing up babym -- not their son or daughter.

Mrs. Pogrebin's point is that the more parents can forget that their baby is a boy or girl, the better an adult that baby will one day become. As she succinctly puts it, "The most important message of this book can be put in a single sentence: 'Non-sexist childrearing is good for your child.'m "

Why is it good? Because, she argues, it frees your child from the prison of gender and the cage of can'ts which trap little boys and girls in sex role stereotypes -- e.G., little girls can't play hockey and little boys don't play with dolls. However trivial such prohibitions may seem, she believes that their cumulative effect is the indoctrination of children with a kind of double jeopardy: "Boys are better. Girls are meant to be mothers." Because of this attitude, Mrs. Pogrebin reasons, children learn to stifle those aspects of their potential and individuality that do not conform to sex role stereotypes and grow up into adults who are only half alive.

Mrs. Pogrebin, as you may have guessed, has as little use for the adjectives masculine and feminine as she does for the Gallic motto, "Vive la difference!" She feels that these distinctions are not only harmful but meaningless because the differences between the two sexes are less than those among members of the same sex. As she elaborated in a telephone interview, "We have yet to see what is pure gender. . . . We will know more about what 'masculine' and 'feminine' mean when we get rid of everything else."

Mrs. Pogrebin, who spent eight years researching and writing this obviously controversial book, comes to her subject well qualified by both professional and practical experience. A founder and editor of Ms. magazine, she was also a developer and editor with Marlo Thomas of "Free to Be . . . You and Me," a record, book, and television special consisting of non-sexist songs and stories. She contributes the "Working Woman" column to Ladies Home Journal and is the author of two books. Equally important, she has logged 15 years of child-rearing experience during which time she and her husband, a lawyer, had the opportunity to apply their shared theories to their three children (twin daughters and a son).

The core of her convictions is "parity parenthood," which means that fathers should be more involved in child care and women more active in the marketplace (and she doesn't mean the supermarket). In other words, as long as the separation of roles remains so drastic, with the mother as care-giver and the father as breadwinner, their children will grow up with the same arbitrary, restrictive notions of acceptable behavior.

The most serious consequence, Mrs. Pogrebin believes, is that girls learn self-contempt because of their inferior status as "mere" mothers and boys in turn learn to deny a gamut of emotions and experiences, from the nurturing to the aesthetic, with the remotest feminine connotations. And it starts early. As Mrs. Pogrebin ruefully observes, the worst insult one little boy can level at another is to call him a sissy or a girl.

Another damaging effect of the polarization, as she sees it, is the antagonism that can ensue between the sexes, with boys despising girls for their limitations and girls envying boys their options, when in fact both are equally the victims. Mrs. Pogrebin feels that men benefit by sharing more fully in the rearing of their children. She comments, "Raising children is one of the most important things anyone can do. It is toom important for one person to do alone."

Although her children have occasionally had to deal with peer pressure, Mrs. Pogrebin claims that "most children envy them their non-sexist childrearing because it adds dimension to their lives. As kids see it they have more options." In fact the Pogrebin children have become proselytizers of their parents' philosophy, another rarity these days, and Mrs. Pogrebin is proud that "we are such a close family. I cannot believe there is anything wrong with these ideas because of our closeness. My passion is based on that fact."

Mrs. Pogrebin admits that the structure of society works against role sharing. Though men's work schedules may make it difficult for them to participate in child care and household responsibilities during the day, Mrs. Pogrebin does not accept this as an excuse and insists that in the time they are home they share these tasks equally with their wives. An entire chapter of the book is devoted to alternative contracts which a couple can consider according to their needs.

Mrs. Pogrebin sees sexism around every corner -- not only within the family but in other influences that are brought to bear upon children through schools, sports, television, children's literature, entertainment, and even our language. These range from the severe -- boys who develop an exaggerated fear of failing in school and girls of doing well -- to the silly (beware the Bobbsey Twins!) Obviously, the vigilance required to detect and neutralize sexism is daunting. One may conclude that the only way to make non-sexist child-rearing really work would be to establish a utopian community cut off from the rest of the world. But if Mrs. Pogrebin will appear to some readers to be carried away by her thesis, others will find her uncompromising book of relative use within the framework of their own sense of family.