There is bad news for anyone who still clings to the belief that growing up in a one-parent home or with a working mother has no harmful effects on a child.

This belief is, of course, very reassuring to the millions of people whose children are not permitted to stand in the way of their decision to get divorced, as well as to the swelling ranks of mothers (whether married or single) who deposit their babies in day-care centers on the way to work. It has also been obligingly bolstered in recent years by a number of "scientific" studies.

According to one of these studies, "Differences in long-term behavior between children from one- and two-parent homes of comparable economic status are small or even non-existent." According to another, "There is no evidence that having a working mother per se has harmful effects on children."

How, then, do the authors of these studies account for the many "harmful effects" that have become visible even to them in the generation of children growing up under such circumstances? These effects include a rise in criminal behavior, a rise in drug and alcohol use, a rise in teen-age pregnancy, abortion and venereal disease, and -- as we were reminded by the rash of suicides in an Omaha high school last week -- a rise in the adolescent death rate from violent causes (homicide and motor vehicle accidents in addition to suicide). The only thing that seems to have declined is academic achievement.

Since the statistics documenting these gruesome facts have been drawn from a sample consisting entirely of white adolescents, the blame cannot for a change be assigned to racism. Deprived of their usual all-purpose explanation, the social scientists in question fall back on what one of them calls "the broader economic and social forces that shape the experience of children and parents" -- forces like family income and the quality of the schools.

But -- and here we come to the bad news I began by announcing -- this fallback position has just been blown out of the water by two sociologists, Peter Uhlenberg and David Eggebeen of the University of North Carolina, writing in the current issue of The Public Interest.

If the fallback position were correct, the particular "economic and social forces" that all parties to the debate see as having detrimental effects on children should have been getting worse. Yet during the period when the teen-agers in the Uhlenberg-Eggebeen sample were growing up (1960- 1980), the economic and social forces generally considered relevant all got better.

So far as family environment itself goes, for example, Uhlenberg and Eggebeen find that in every one of the agreed-upon factors -- poverty, large number of siblings and low parental education -- a dramatic improvement took place.

Moving from the family to the school, the two sociologists find much the same picture of improvement in the factors usually accepted as important in this area too. Expenditures per pupil went way up and class sizes went down. Teachers became more highly educated, and many of the measures advocated by reformers (compensatory programs for the disadvantaged, more guidance counseling, courses in sex education and so on) were instituted.

Finally, the amount of money spent on children by the federal government expanded at an unprecedented rate. There were now programs ranging from recreation to drugs, from job training to child abuse, from nutrition to delinquency. So much for "the broader economic and social forces" that are the last refuge of those who insist, in the words of the well-known psychologist, Kenneth Keniston, that "there is nothing to be gained by blaming ourselves and other individuals for family changes."

Uhlenberg and Eggebeen, by contrast, believe that "this preoccupation with removing responsibility for negative outcomes from individuals has diverted attention from what may be the most critical determinant of all" in the deteriorating condition of American adolescents: "The bond between child and parent."

Focusing their attention on this "determinant," the two sociologists find hard statistical evidence for what we all know simply from looking around. They find more and more people for whom "self- fulfillment" takes precedence over all other values. Accordingly, they find fewer and fewer people who believe in sacrificing themselves, or even their own convenience, to the needs and demands of their children. Thus an astonishing two-thirds of all American parents feel that "parents should be free to live their own lives even if it means spending less time with their children."

In these expressed values, and in their two major practical consequences -- the general refusal of parents to stay together for the sake of the children, and the huge increase in the percentage of mothers working outside the home -- Uhlenberg and Eggebeen find, quite reasonably, "a declining commitment of parents to their children."

It is to this declining commitment that, they suggest, we should turn for an explanation of the horrible fact that, during a period when presumably beneficial changes were being made in all the other features of family structure, as well as in schools and government programs, "the proportion of adolescents behaving in ways destructive to themselves and others grew ever larger."

Bad news indeed for parents who have relied on "the broader economic and social forces" to silence natural feelings of guilt over putting their own interests above those of their children instead of the other way around.