By Marcia Millman

Harcourt. 275 pp. $25

A few years ago, the magazine that was then called Modern Maturity ran a harmless- seeming sidebar asking its readers: Do you happen to have any troubles relating to your adult siblings? If so, write and tell us about it. What the editors expected was a series of lighthearted tales along the lines of: "My sister took all the best family china when our mother died, but later we were able to divide things nicely." I was assigned to write a cheery piece about how we may have our differences, but, as Beth once opined in "Little Women," "birds in their little nests agree."

What came in were stacks of letters that addressed the great mystery of life in America. One woman, born of a knife-throwing act, was sold at birth for $750, and had spent her life searching for her brother, who was, by then, involved in organized crime. Another woman, abused at the age of 8 by her stepfather, was thrown out of the house as a slut by her own mother, who even 30 years later spat on the floor when she saw her. She and her half-sisters had to meet in private, miles out of town. Another man in his seventies was watching television in a New England town when he received a fateful phone call: "I think I'm your brother," a strange voice said. "Oh, no," the man replied. "I was an only child." "I think you'll find there were nine of us," the strange voice said. And indeed, there were, all having grown up in the same town, bowling in the same bowling alley.

None of this made it to the pages of Modern Maturity, because -- talk about "troubles"! The best-kept secret in the country is how, between illness, acts of God, impetuous love affairs, ill-conceived crimes and truly outstanding incompetence, we're able to keep even the flimsiest fragments of family together.

So it isn't the relationships of sisters alone that make "The Perfect Sister" so absolutely riveting and fascinating, but the back stories of these sisters, which shine unhealthily like fried ham in the sun. Humans are stranger than we can ever know.

In the introduction, not surprising- ly -- except that she herself was surprised -- Marcia Millman, a social psychologist and professor of sociology at the University of California at Santa Cruz, mentions that the majority of sisters she interviewed described their own mothers as "difficult: controlling, critical, depressed, withdrawn, guilt-inducing, or unaccepting of them. Much more often, they remembered their fathers as a much greater source of love and warmth and understanding." She describes a suburban world where men were banished from the home to the garage by their strict, rule-making wives. (But maybe the beleaguered men simply chose to flee the furious women in the house? Who knows?)

Many of the marriages that produced these sets of sisters began with unplanned pregnancies. Divorces sundered these marriages, producing more siblings, more parents. Grown-ups and children died, leaving their survivors in depression. Parents simply bailed: One mother here leaves for Paris for four and a half months, for no reason her daughters can fathom. Then she returns, for no reason her daughters can fathom.

Within this chaos and human folly, little children must grow up, get fed and clothed, go off to school and, for God's sake, stay out of trouble. Many brothers in these narratives leave home and are rarely heard from again. Many sisters -- even in this day and age -- marry the first guy who comes along to get out of the house. Then they try to keep in touch with their sisters and parents, harmonizing husbands and brothers-in-law. It's a gallant effort.

Millman tries to make sense of these family narratives, naming the Depressed Sister, the Invisible Sister, the Outsider Sister, the Bad Sister, the Betrayed Sister, the Wishful Sister, and so on. But her material drowns her attempts to make any sense out of what she sees, because, again, it's surpassing strange. "I did adore my father, but he didn't give me the accolades I wanted," one woman says. What in fact he did say to her is: "I never liked you. I never loved you. Just looking at you makes me sick to my stomach." A mother, who put her daughter up for adoption years before, keeps her at bay for 17 years (!) before agreeing to meet with her. And my very favorite quote comes from what might be called the Discombobulated Sister: "My niece, Susan, is not with us. Six weeks before her marriage, with her wedding dress lying on her bed, she killed herself. None of us were crazy about the bridegroom. I didn't think the wedding would happen. I didn't even buy a plane ticket."

Engaging as these episodes are in the anecdotal telling, I would fault the author for carelessly comparing a family of four sisters to those in Louisa May Alcott's "Little Women." In Millman's family, the mom "receded so far into the background . . . that she almost wasn't there . . . [the] father was clearly the dominant parent. In the real "Little Women," of course, Marmee rarely if ever shuts up; the father is absent for most of the book and is an invalid when he does show up. Millman's hypothetical little women loll by the family pool, watching out for the family children. Meg, Jo, Beth and Amy clearly did much more than that.

But literature, sociology, psychology, don't matter much in this book. It's the families, the stories, the siblings, that give the term "weird sisters" a whole new meaning.