Too much of the wrong kind of television can make children aggressive or overweight, interfere with school performance, encourage them to try alcohol, drugs or sex, and persuade them that the world is more violent, more white and more middle-class than it is.

Those are the conclusions reached by a task force of the American Academy of Pediatrics, which issued a "call to action" on children's television at a conference at Yale University School of Medicine earlier this month.

"No other country in the world has done as poorly for its children as the United States," said Dr. Benjamin Spock, who headed a lineup of experts condemning the lack of quality children's fare on commercial stations.

"At present there are no commercial programs for children," he said. "The things that pass for them are really half-hour-long commercials on the life of a doll they are trying to sell."

The pediatric academy announced its support of a bill, currently being considered by committees of both houses of Congress, that would require commercial stations to provide seven hours a week of educational programming for children 12 or younger.

Pediatricians have expanded their concerns about program content to include not only violence, but also television's portrayal of alcohol, drugs, sexuality, the elderly and ethnic groups.

Yet despite more than 3,000 studies of the impact of television on children's behavior, experts disagree over what effects have or have not been proven.

"The big thing we know is that children learn from TV," said Dr. Victor Strasburger, associate clinical professor of pediatrics at Yale. "The real question is what they learn from it."

Studies concluding that children who watch more television are more violent, for example, can be criticized because they do not explain whether television viewing leads to an aggressive personality, or vice versa.

But Strasburger, Spock and other pediatricians say such arguments should not stand in the way of change, because there already is abundant evidence that the world presented to children on prime-time television is not one that adults would wish them to imitate.

"The average American child before reaching adulthood has watched 18,000 murders on TV," said Spock. "It doesn't mean that a sensitive, well-brought-up child is going to turn into a thug, but everybody is desensitized to a degree."

Strasburger said one of his best childhood friends was injured when he jumped out of a second-story window trying to fly like Superman, but that such examples of direct imitation are rare. Instead, he believes more subtle links exist between television and health problems such as accidents, suicide and teen-age pregnancy.

"After 1 year of age, violence is the leading cause of death in American children and teen-agers: accidents, homicide and suicide," he said. "None of those are medical. They don't involve drugs that we can give. That makes it very frustrating for pediatricians to deal with."

Strasburger and four other doctors served on a task force to evaluate television's impact on children's health and to advise pediatricians and parents how to respond. Among their conclusions:

Repeated exposure to television violence promotes "a proclivity to violence and a passive response to its practice." George Gerbner, dean of the University of Pennsylvania's Annenberg School of Communications said TV violence teaches children and adults that "the world is a very dangerous place in which . . . they are dependent and need protection."

TV viewing "increases consumption of high-caloric . . . snacks" and can lead to obesity. Although TV characters are almost universally thin, task force chairman Dr. William Dietz found a strong correlation between hours spent watching television in children and obesity in teen-agers.

Learning from television "is passive . . . and detracts from time spent reading or using active learning skills." Strasburger said that when he sees a child who is failing in school, "My first response is . . . get the TV out of his room."

TV's portrayal of alcohol and drugs is "unrealistic . . . and indirectly encourages their use." "On TV alcohol is the number one beverage" drunk by series characters, Strasburger said. "In real life, water is." The average child watches about a thousand beer and wine ads a year, he said.

Sex roles and sexuality as portrayed on TV are "unrealistic and misleading," and "the risk of pregnancy is rarely considered." Strasburger pointed out that sex on soap operas takes place three times more often between unmarried lovers than between husband and wife, and contraception never seems to be a concern.

Television promotes ethnic and racial stereotypes and an unrealistic view of society. Male characters outnumber females three to one, Gerbner said, and children, the elderly and minorities are all underrepresented. "The child learns a social hierarchy . . . to be put in his or her place," he said.

In an average week's viewing, he added, a child sees 41 policemen, 23 criminals, 12 doctors, 15 businessmen, six lawyers and three judges.

Pediatricians should educate themselves about the health consequences of television viewing, counsel families on the issue, and work with community groups, networks, producers and writers to improve programming, the task force advised.

Positive trends in television, Strasburger said, include the realistic family presented on NBC's "Cosby Show" and the three networks' efforts to purge scripts of cigarettes. "In the 1980s only 2 percent of series stars and 16 percent of series characters smoked," he said. "That's great."

Philip Harding, vice president of social and policy research at CBS Broadcasting Group, took issue with the task force's conclusions, saying they are drawn from one-sided research and "create the impression there has been a consensus. There is not a consensus on the effects of television.

"If you're going to talk about the social effects of the media . . . you try to be impartial. You don't concentrate just on negative judgments. Other people just as competent, just as honest, just as well-intentioned have come up with totally different results."

Harding also disagreed with Gerbner's contention that children's cartoon shows contain 20 violent acts per hour. "He has always held that pouring milk on an elephant is an aggressive act," he said, "and he counts that as violence."

Pediatricians and consumer groups don't want to censor television, but to improve its quality and educational value, according to Peggy Charren, president of Action for Children's Television.

"If you had, on 'Knight Rider,' say, everybody buckling their seatbelts, and you did it on all the other programs . . . gradually all of us would buckle our seatbelts," she said.

Gerbner called television a "symbolic environment" that deserves its own environmental movement. "Whoever tells most of the stories to the children of a culture influences, in a very fundamental way, the way people grow up," he said. "For the first time in human history, it's no longer parents, the school or the church, but television that tells most of the stories."