The camera went the mirror one better. It gave us a new and more objective way to see ourselves, not just as we are, of course, but as we were.

This ability is put to unusually good use in "From 7 to 28 Up," the awkwardly titled but completely engrossing British documentary that airs at 8 tonight on Channels 26, 32 and the Maryland public TV stations. More than two decades in the making, literally, the film records life at seven-year intervals for a group of young Britons first encountered as schoolchildren in 1964.

A longer version of the documentary was previously released to theaters. The PBS cut runs 2 1/2 hours.

Michael Apted, who produced and directed for Granada Television, went on to make such Hollywood movies as "Coal Miner's Daughter," but what matters here is what the children in the film went on to do. And be.

One of the most striking things about the introductory footage is how articulate almost all the children were at the age of 7. They don't hem and haw and mewl about; they are forthright and blunt. They could only be British.

But then the film starts moving forward in time. Bright eyes and great expectations dim as years pass; some of the children saw the rewarding lives they predicted for themselves come true, others did not. The film means to be quite specific about social stratification by background and environment (and a great deal is made over the difference between public and private schools), but the stories also reflect universal yearnings and struggles.

"Certain people have more options than others," the interviewer says late in the program. That isn't much of a thunderbolt. But the means of exploring it is. And nothing but film could make it possible to leap through a person's first 28 years of life in minutes, or to contrast someone's attitudes and beliefs as they are modified by time, maturity and a growing if begrudging acceptance of reality.

A smug young lad named Andrew who announces at the age of 7, "I read the Financial Times," and says he wants to go on to Cambridge for his education, does, and becomes a lawyer. A little girl named Suzi who says at 7, "Some boys can be nice, and others can be horrible," and says at 21 that she is "very, very cynical" about marriage, marries two years later.

"I don't like babies," she says at 21. Cut to: a shot of her first baby cradled in her arms. She has changed her mind. People do.

Neil, who grew up in a Liverpool suburb, says at the age of 7, "When I get married, I don't want to have any children because they're always doing naughty things and making the house untidy." He says he wants to be an astronaut when he grows up, or, failing that, a bus driver. But he never quite does grow up.

At 21 he is an embittered college dropout and construction worker, and at 28, an unemployed nomad taking temporary shelter in a mobile home. He says, "I can't see any immediate future at all." One longs to revisit him again when he is 35.

At the outset, the narrator says the original group of children represented "startlingly different backgrounds," but in fact there is little racial or ethnic diversity. While the film may have limited value as sociology, it has real worth as a human study.

Those who seem to have found the most satisfying lives among the original group of children aren't necessarily the richest or worldliest, nor the ones who ended up doing precisely what they thought they would do. Indeed, two of those who did and appear to be living lives of plush affluence refused to be interviewed again at 28.

By contrast, there is the jovial Tony, who wanted to be a jockey, but after three races was unable to make it in the profession. So he studied to become a London cabbie instead. He is also taking acting lessons.

Married and the father of two in the most recent footage, Tony seems gratifyingly free of regret or complaint. Then, suddenly we see him at 7 again, racing out of the back door of his home and falling flat on his face in the yard. He takes the spill and gets right up, races gamely over to the fence and climbs it. He is on his way.

Probably the most admirable of those biographied is Bruce, who at 7 wanted to become a missionary and at 28 is a math teacher in a multiethnic London school, where he says he enjoys "being a part of people's advancement." But there's also Nick, a farmer's son who dreamily talked of the moon as a boy and is now a professor of physics at the University of Wisconsin.

He left England, he says, because although he was well trained by the school system, his skills weren't considered very marketable once he acquired them. Whereas the land of opportunity lived up to its billing.

The filmmakers could be considered sexist since boys outnumber girls in their study and they seem to ask the women mainly about maternal matters. But the film still stands as a virtually incomparable vicarious experience, a chance to invade the privacy of others in a productive, enlightening way.

Maybe PBS didn't make this program, but only PBS would show it. As the year ends and one looks back on its television, public TV -- from "Eyes on the Prize" to "7 Up" -- has much of which to be proud.

'Scared Sexless'

It appears we may all owe Geraldo Rivera an apology. He's forever being blamed for lowering TV news standards, but the networks are out to prove they can do that just as well without him.

"Scared Sexless," the NBC News documentary at 10 tonight on Channel 4, is as tawdry as Rivera at his gaudiest, an hour of flashing lights, rock tunes and gags. It is so poorly executed and carelessly conceived that, had it been produced at ABC News or CBS News, it would probably have been deemed unairable by executives and shelved. Or perhaps that's being too optimistic.

NBC News scored big ratings in June with its last Connie Chung documentary, "Life in the Fat Lane," and so it has modeled this new report -- about changing sexual attitudes and practices in the age of AIDS and other rude awakenings -- on that one, even though the myriad ramifications of, for example, death by sexually transmitted disease would seem a less yockable topic than dieting.

Nevertheless, "Sexless" features, as part of its glitz blitz, the unsavory spectacle of guest stars plugging movies on a news program.

Goldie Hawn gigglingly promotes her current release (and box office dud) "Overboard" and Alan Alda bangs the drum slowly for his film "A New Life," due next year. "Overboard," Chung dutifully informs us, costars "hunky Kurt Russell," Hawn's significant other.

We may not only owe Geraldo Rivera an apology; we may owe Rona Barrett one as well.

Alda gets a hypey, talk-show intro from Chung, who claims that his films have contained "some of the best recorded reflections of our sexual selves." They have? Chung, who cowrote the abysmal, chatty, press-release script with director Sid Feders, has other trenchant observations up her sleeve, such as:

"Marcus Allen is as close to a single stud as one gets."

Allen is a member of the L.A. Raiders football team. He is hauled into the documentary not because he sheds light on any of its topics, not because of acknowledged expertise, but because he is a celebrity. NBC is perfecting All-Star News, crossing the documentary form with the "Hollywood Squares."

"Coming up," teases Chung, prior to a commercial, "Goldie Hawn, Alan Alda, and premarital sexual mores -- auditions for a spouse."

Obviously it was reasoned the viewing public would be turned off at the thought of another grim look at anything related to the AIDS crisis. And PBS attracted considerable attention with its determinedly friendly informational broadcast "AIDS: Changing the Rules."

So executive producer Paul W. Greenberg must have decided he should out-funsy the other guys. A female comic was brought in to add jokes at regular intervals. Yes, jokes. There are cutaway shots of Chung laughing appreciatively. And the script maintains that dreadful winky tone.

"Whether you're a hamster or a hunk, sex for you is changing," Connie tweets. "Fear of death could be the cold shower for casual sex," says she. "What we became, we are," quoth Zen master Chung.

Only Secretary of Education William Bennett, who can be counted on for blindly insensitive gaffes, sounds dumber than Chung. He says, on the subject of sexual experimentation by teen-agers, ". . .AIDS may give us an opportunity to discourage it, and that would be a good thing."

Naturally the movie "Fatal Attraction" comes up when the issue of marital fidelity is raised. A young married couple talk on camera about the husband's having committed adultery. "It's art imitating life," chimes Chung, comparing this real-life case with the plot of the hit film. And yet from the evidence presented, no shrieking banshee attempted to stab this particular husband with a butcher knife and was then drowned in a bathtub.

Virtually all the information in the documentary is stale. Anyone half-attentive during the past two years has heard it before. Indeed, it could well be argued that Geraldo's done it better (well, certainly with more brio) on his syndicated specials. What appears to have happened is that somebody at NBC decided a sex documentary might do well; then the minions were put to work trying to scrape together material.

And sign up those Glamorous Guest Stars!

"Scared Sexless" represents a new low-water mark in cynicism and commercial-mindedness from a network news division. Chung sullies her own good name in the process; it will be hard to take her seriously again for a while. She displayed more integrity larking it up on David Letterman's Christmas show than she does standing between two beds (really) to anchor this one.

There has to be a limit to how deeply one will dip into the gimmick bag in order to hook viewers on a documentary. About the only thing missing from "Scared Sexless" is Doc Severinsen and the "Tonight Show" band to play the celebrities on and off. Maybe next time.