What is happening to children who sit in front of the family television for some 26 hours a week - the national average for children ages 2 to 11?
Do they become more aggressive after seeing violent programs? Do the many hours of viewing slow their learning or speed it up? How does it affect the way they (and adults) view others and society?
A new round of debate on these questions has been stirred by a recent report by the National Institute of Mental Health on television's impact on behavior. Most attention so far has centered on the report's statement that evidence is ''overwhelming'' that televised violence causes aggression in children.
Experts in television research interviewed by the Monitor indicated they agreed with these findings.
But besides probing the question of television violence, a largely ignored portion of the report explores how television affects children's imagination, creativity, learning, and emotions, and how television can make or break stereotypes.
The study calls upon parents to help their children become more critical viewers of television, and help them separate fantasy from reality.
For example, the report cites research showing that watching violent programs and cartoons is tied not only to aggressive behavior among children but to less imaginative play. But television can ''enhance'' a child's imaginative play if an adult watches with the child and helps interpret what is happening.
Parents should recognize that ''television is not just entertainment or innocuous use of time,'' says Eli A. Rubinstein, a research professor at the University of North Carolina's school of journalism and one of the consultants for the report.
''Television has a profound effect on the way our children learn,'' says George Gerbner, another consultant on the report and Dean of the Annenberg School of Communications at the University of Pennsylvania.
These and other researchers interviewed called for changes in TV programming to make television a better educational tool, placing more emphasis on society's best traits and less on negative ones.
They want to see women in less stereotyped roles, to have more working-class and elderly people portrayed, less alcohol used, and less violence, in what they call a truer reflection of American life today.
But TV network officials said in interviews that television's main role is ''entertainment.''
''Television is not supposed to be a true reflection of society,'' says Gene Mater, senior vice-president of CBS Broadcast Group. The main aim of television is not education, but ''entertainment,'' he said.
''I'll go home after a day and riding the (commuter) railroad and I'll have a snack and say to my wife: 'I'm going in to (to watch TV),' and I want to laugh. I'm not there to be informed, to be instructed,'' said Mr. Mater.
Avoiding negative stereotypes is a good goal, but ''it gets complicated,'' said J. Ronald Milavsky, vice-president of news and social research for NBC.
What some viewers may see as a stereotype sometimes reflects what is actually happening in society, and therefore is appropriate to include in the program, he says.
Recasting the role of television the way some social researchers would have it ''can't be done,'' said Mr. Milavsky.
As for the report's finding that television violence is clearly linked to aggression in child viewers -- something all three networks dispute -- ABC's director of community relations, Jane Paley, contends such studies are not ''conclusive.'' Violence among child viewers is ''due to the people in their life -- not the television in their life,'' she said, but did not supply any study tosupport her statement.
Findings from the report, along with comments from some of the researchers, include the following: TV AND AGGRESSION
The lightening rod of the National Institute of Mental Health's (NIMH) report is the finding that ties televised violence to aggression among children. Even cartoons were found to be aggression-inducing among young viewers.
''The research question (on the link between TV and aggression in children) has moved from asking whether or not there is an effect to seeking explanations for the effect,'' the report states.
''Hundreds of studies'' find that televised violence causes aggression among children, while only a few studies find otherwise, says Dean Gerbner.
One study supporting the TV-aggression link was funded by CBS. It found that teenage boys in London, according to the boys' accounts, were more likely to engage in ''serious violence'' after exposure to television violence.
CBS disputes the finding, saying the research methods used were not sound. But Dean Gerbner, who has done many studies on TV and violence says that the researcher was a teacher of methodology and that the study was not faulty. (About 90 percent of all research on television's effects on viewers has been conducted since 1972, when a surgeon general's report found ''fairly substantial experimental evidence'' that TV violence caused short-term aggression in some child viewers. The new report summarizes that research.)
NBC is preparing to publish the results of a large-scale study it sponsored which found no link between television violence and children over the three-year time period studied. Researchers monitored violent television shows and the behavior of a group of elementary students which viewed them.
Professor Rubinstein finds no fault in the methods used in the NBC study but says: ''Not finding a positive result is not a denial (that there may be a result),'' that is, a link between televised violence and aggression. NBC's Milavsky agrees but says ''This is not just an ordinary study. It's not just a matter of not having an effect.
CBS's Mater criticizes the new NIMH summarizing report for a ''remarkable degree of unfairness.''
''They present the verdict 'guilty,' and sometime later give you the evidence ,'' said Mater. Volume 2 of the NIMH report, which will include details of the reports upon which Volume 1 is based, will not be ready for release until later this year. Dean Gerbner says none of the reports the summary volume is based on are new. But Mater says some of the reports are not readily available. TV AND LEARNING
A somewhat less clear link is shown by the report between achievement and television viewing habits at various ages.
''Among young students up to about the eighth grade, those who watch television about an hour or two a day get higher scores on reading than those who watch less television'' -- but after the eighth grade ''reading scores begin to decline commensurate with increases of television-viewing times,'' the report states.
In one study of students, heavy television viewers began reading more than light viewers. The heavy viewers read mostly stories about families, love, teen-agers, and television and movie stars, while the light viewers preferred more science fiction, mysteries, and nonfiction.
Gerbner says the report shows heavy television watching may slow down a bright child but help others develop intellectual skills.
Children and adults learn poor eating habits from seeing so much snack and junk food eaten on television, according to the report. And ''alcohol consumption is common; it is condoned and is presented as a part of the social milieu.'' One study estimates a child daily views at least 3,000 episodes of drinking a year.
TV subjects rarely use seat belts when they drive, something one ABC official thinks should be corrected. TV AND THE FAMILY
Except for cartoons on Saturday, there are few daily or weekly childrens' programs. Peggy Charren, president of Action for Children's Television, in Newton, Mass. is suing the Federal Communications Commission to try to get it to require more children's programs.
''We wouldn't put up with a public library that has only comic books, but we're putting up with that on TV,'' she says.
An ABC official notes that the network periodically runs children's specials. Meanwhile, ACT charges that children usually watching programs made for adults.
What parents can do, according to the NIMH report, is help their children understand between fact and fantasy and the implications of what they see.
They can limit viewing time; encourage viewing of some programs and discourage others; watch with the children, interpreting when necessary; discuss the programs with their children.
One teacher, the report says, sat with some preschoolers guving guiding comments such as ''That boy is in trouble. He is playing hookey and that is bad'' - helping the children understand the implications of what they had seen.
(The report is entitled, ''Television and Behavior: Ten Years of Scientific Progress and Implications for the Eighties. Vol. 1: Summary Report.'' Single copies may be ordered at no charge while supplies last from the National Institute of Mental Health, Room 11-A21, 5600 Fishers Lane, Rockville, Md. 20857 ; or at $5 each from the US Government Printing Office, Superintendent of Documents, Washington, D.C. 20402.