Berkeley - The traumatic effects of divorce arrive most powerfully in the lives of children decades after their parents separate, according to an historic study carried out at the University of California, Berkeley.

The first of its kind to follow children of divorce into adulthood, the study has discovered that while an initial breakup is painful for children, the greatest impact comes when, as adults, they try to form their own intimate relationships and families.

As adults, these children tend to make poor judgments, according to landmark research carried out by Judith Wallerstein, a national authority on divorce and a senior lecturer emerita at UC Berkeley, where she taught for 26 years in the School of Social Welfare. Wallerstein, who is also founder of the Center for the Family in Transition in Corte Madera, Calif,, began the study in 1971 and has followed approximately 100 Bay Area children for 25 years.

The stories of 93 of these children, now aged 28 to 43, and the impact of their parents' divorces on their personal lives, is told in a new book, "The Unexpected Legacy of Divorce: A 25 Year Landmark Study," published by Hyperion. It is co-authored with Julia M. Lewis, professor of psychology at San Francisco State University, and Sandra Blakeslee, science correspondent for The New York Times.

"Our findings challenge the myth that divorce is a transient crisis and that as soon as parents reestablish their lives, the children will recover fully. That doesn't happen," said Wallerstein in an interview.

She emphasized that, in spite of their difficulties, most of the children in this book do eventually conquer their ghosts. They make more mistakes. They have extended adolescences. Finally, after a slew of early marriages and divorces, several of the children find good partners and become good parents. Others still were struggling at the 25-year mark.

"It is doable, but it's harder," said Wallerstein. "Parenting erodes almost inevitably at the breakup and does not get restored for years, if ever. Throughout the postdivorce years, children have less protection and less nurturance.

"We now see that the major hurt is in adulthood when internalized images of the mother, father and their relationship come to center stage and shape the choices their grown children make," she said.

She said the work lives of these grown children largely were unaffected by the divorce, but their personal lives included crippling fears of loss and disaster, fewer marriages, fewer offspring, more divorces, and greater use of drugs and alcohol during youth compared to a similar group of children from intact families in the same neighborhoods.

For the 25-year follow up, Wallerstein interviewed a second group of 44 adults from intact families that grew up alongside the children of divorce and attended the same schools.

Comparisons between their lives offer compelling testimony to the lasting effects of divorce on children. (Except for the divorce, parents' problems in the two groups were remarkably similar, Wallerstein said.)

* Sixty percent of the adult children of divorce are married at this point compared to 80 percent of adults whose parents' marriages lasted.

* Thirty-eight percent of the adult children of divorce have their own children, 17 percent of them out of wedlock. In the comparison group, 61 percent group have children, all in the context of marriage.

* The children of divorce were far more likely to marry before age 25 - 50 percent, compared to 11 percent of the comparison group - resulting in a much higher divorce rate. (Fifty-seven percent of these early marriages failed, compared to 25 percent of early marriages in the comparison group.)

* Only 29 percent of children from divorced families received consistent support for higher education from their fathers, compared to 88 percent of the children from intact families.

* Twenty-five percent of the children of divorce used drugs and alcohol before age 14 compared to nine percent of the comparison group.

Wallerstein said it was a tribute to the resilience and perseverance of the children of divorce that they were able to do well in careers despite the greater difficulty they had getting a college education.

The younger the children were at the time of the divorce, the more they were harmed, said Wallerstein. Preschoolers in this study typically suffered a grievous loss of maternal attention, a loss that is recounted in the book in the story of Paula.

Afflicted by a "vast unsoothable sense of loneliness" since the day her world collapsed when she was four years old, Paula experienced an intolerable deprivation of parental attention throughout childhood. As a young adult, her life became chaotic and self-destructive. Now 33, divorced, with a young child, Paula is working very hard to turn her life around. Her story is one of seven representative case histories in this book that carry the message of the impact of divorce.

Wallerstein said she does not advocate that a couple stay together no matter what their marriage is like. In fact, the worst marriage in the book occurred in an intact family, said the authors, where parents visited a kind of prolonged hell on their children and probably should have divorced.

"In extreme cases," she said, " a divorce can be better for children if one of the parents can turn her or his life around and serve as an example."

But in most cases, "Life will be harder for the child because parenting is harder," said Wallerstein.

She added that the "trickle-down" theory of divorce is a myth. Parents like to believe that if they are unhappy in their marriage, the children also will be unhappy. Conversely, if divorce is better for them, it will be better for the children. But things don't work that way, she said. Children frequently do not share their parents' unhappiness with a problematic marriage, while a divorce brings pain into their lives that, until now, has gone unrecognized.