When you consider that each year since 1972 more than a million children have been in families that divorced, it makes sense for the House Select Committee on Children, Youth and Families to take a look at the impact of divorce on children. This it did last week, and experts who testified agreed on at least one important point: The way parents behaved after divorce, toward each other and their children, had much more effect on the children's development than did the divorce itself.

Dr. Gene H. Brody, codirector of the program for the Study of Competence in Children and Families and a professor in the Department of Child and Familiy Development at the University of Georgia, testified that behavioral scientists are beginning to examine "the interplay among the stresses" experienced by members of single-parent households. "Some children exhibit severe or sustained disruptions in development, whereas others seem to negotiate a turbulent divorce and stressful aftermath and emerge as competent, well-functioning individuals. Thus, the negative effects of divorce on children are not inevitable."

He cited research on middle-class preschoolers that showed that divorce often results in disorganized households. Children had less frequent meals with their mothers and irregular bedtimes, and arrived late to school. "Furthermore," he testified, "divorce was followed by a breakdown in the mother's use of appropriate and consistent discipline, fewer demands for mature and independent behavior from the child, and less parent-child communication.

"Significantly, it was primarily in those families in which household disorganization was disrupted, and in which the quality of parenting was severely undermined by the stress of divorce, that children displayed more behavior problems . . . which were associated with declines in intellectual abilities and social relationships over a two-year period. However, children whose divorced mothers maintained consistent household routines, remained firm but sensitive disciplinarians, and encouraged independent, mature behavior, displayed few intellectual and social deficits . . . . "

One study Brody collaborated on of 126 divorced mothers found that "the less money the mothers had at their disposal, and the more children they had to rear, the more depressed they were." The majority were employed, he said, but they did not have the skills for well-paying jobs and high quality child care.

He said a second study found that "higher levels of depression among custodial mothers were associated with lower grade point averages, higher levels of depression and anxiety, and more health problems among the adolescents. Ongoing parental conflict was associated with poorer school performance, lower grades, less social competence with peers, more behavior problems at school, and self-perceptions that they were less intelligent and popular than their classmates. Importantly . . . when custodial mothers were not depressed and harmonious relations existed between the ex-spouses following divorce, adolescents functioned competently at school and perceived themselves to be academically and socially capable."

A third study found that "whether the adolescent resided with one or two parents, better intellectual and social performance resulted if they were exposed to lower levels of parental conflict," Brody testified.

Dr. Judith S. Wallerstein has, since 1971, been the principal investigator of the California Children of Divorce Project, the longest continuous study of such families in the nation. She testified that the study of 113 mainly white, middle-class children, who were 3 to 18 at the time of separation, shows that many weathered the breakdown but a significant number "continue to suffer the effects of the divorce a full decade after the marital rupture." She said families need specialized divorce services, such as counseling, mediation, an adequate and fair child support system, quality child care, and after-school child care programs for children and adolescents.

By 1984, more than 9 million children lived with divorced or separated parents. Their numbers have become so substantial that even if a small portion of them are living with depressed, stressed-out, combative parents, it is a significant group of young people.

Much is being learned now about what factors can jeopardize their development and what can help them cope. This is information parents, judges, educators and policy makers need to learn about and understand, and then, perhaps, divorce will become less destructive to the growing number of children affected by it.