I remember staring at the paperback edition of Wilson Brian Key's 1973 bestseller Subliminal Seduction, trying to see the nude woman in the ice cubes. I never could.

Key claimed advertisers routinely use hidden images to manipulate consumers. His determined search for such dirty tricks rose to new heights of absurdity in his 1980 book The Clam-Plate Orgy, the title of which refers to the sex scene he perceived in a picture of fried seafood on a Howard Johnson's placemat.

Yet Key's theories clearly had a lot of popular appeal. They still do, to judge by the furor over the GOP ad in which the last four letters of the word "bureaucrats" flashed on the screen right after a picture of Al Gore.

The controversy focused mainly on whether the juxtaposition was deliberate. Less discussed was the issue of why anyone should care, since the idea that such barely perceived images affect people's attitudes or behavior has been thoroughly debunked.

Key, who wrote four books on the topic, was not the first person to popularize the concept of subliminal advertising. The Hidden Persuaders–Vance Packard's 1957 "expos√©" of the ad business, in which he credulously accepted the boasts of people notorious for exaggeration–cited a theater that supposedly got customers to buy more ice cream by flashing ads on the screen during movies.

The year Packard's book was published, an adman named James Vicary claimed to have done something similar during a six-week experiment at a movie theater in Fort Lee, New Jersey. By flashing the messages "Eat Popcorn" and "Drink Coke" on the screen for a third of a millisecond at a time, Vicary said, he had raised Coke sales by 18 percent and popcorn sales by 58 percent.

News of Vicary's experiment caused a sensation, prompting expressions of concern from members of Congress, the Federal Communications Commission, and the National Association of Broadcasters. But Vicary refused to supply his data, and his results were never replicated.

In a 1962 interview with Advertising Age, Vicary indicated that his study had been a hoax. Calling his technique "a gimmick," he confessed that "we hadn't done any research, except what was needed for filing for a patent. I had only…a small amount of data–too small to be meaningful."

Three decades later, York University psychologist Timothy E. Moore observed in the Skeptical Inquirer that "recent reviews of research findings in subliminal perception have provided very little evidence that stimuli below observers' subjective thresholds influence motives, attitudes, beliefs, or choices." As for embedded images that supposedly make us more susceptible to ad pitches, "there is no evidence for such practices, let alone evidence for such effects."

The persistent belief in the power of subliminal advertising, despite the lack of evidence, is part of a broader mythology that depicts people as robots who receive their programming from the mass media. The same view dominates the ongoing debate over violence in entertainment.

Testifying before the Senate Commerce Committee the other day, Lynne Cheney, former chairwoman of the National Endowment for the Humanities and wife of Republican vice presidential candidate Dick Cheney, quoted columnist Peggy Noonan, asking us to imagine children as fish swimming in the ocean. The stories presented by popular culture are "waves that penetrate through the water and penetrate through our children"; "they go through our children again and again, from this direction and that."

But children are not fish, helplessly exposed to influences that simply go through them (presumably warping their insides on the way). They are active, intelligent consumers of entertainment who choose what to watch or listen to and how to interpret it.

The idea that a kid who hears Eminem say "Bitch, I'm a kill you" will naturally want to murder someone is no more plausible (or scientifically grounded) than the idea that a moviegoer who sees "Drink Coke" and "Eat Popcorn" will be seized by an irresistible urge to visit the refreshment stand. If a message is not compatible with an individual's values, he always has the power to reject it.

Parents obviously have a role, through implicit and explicit moral instruction, in shaping those values. If they do their job right, their children will learn to be skeptical about what they see and hear–including alarmist claims about their own vulnerability to bad influences.