"Subliminal" Ads Remain a Myth

We tried— and failed — to replicate the infamous 1957 experiment by James Vicary


Did he, or didn't he?

The history of advertising is a history of controversies, legends, clever scams, and even a few mysteries. The story of James McDonald Vicary is all of those.

In September 1957,  a 42-year-old market researcher called up a press conference. Some 50 reporters from the US and Britain showed up, from such newspapers as Wall Street Journal, Newsweek, and Sunday Times, as well as the trade press: Printers’ Ink and Advertising Age. There, Vicary announced his new invention that would, he said, change advertising forever. He called it “the invisible commercial.”

He showed a film and overlaid Coca-Cola messages using a device called tachistoscope – a kind of projector that can produce flashes that last fraction of a second.

At the news conference, Vicary announced the result of a test he had just concluded at a movie theater at Fort Lee, New Jersey. The test that he said had ran for 6 weeks and involved 45,000 movie goers, involved projecting two advertising messages: to drink Coca-Cola and to eat popcorn. The messages were flashed every 5 seconds for only 1/3000th of a second – too quickly to be noticed.
The invisible commercial, Vicary claimed, had increased popcorn sales by 57.7% and Coca-Cola sales by 18.1%. He called his method “subliminal advertising.” The next day, the news was in every major newspaper. His phone started ringing.

The timing, in retrospect, could not have been worse. Earlier that year, Vance Packard published his explosive Hidden Persuaders that exposed Madison Avenue’s efforts to turn consumers into puppets through motivation research and subconscious persuasion methods. Vicary’s successful publicity stunt backfired. Before short, he got summoned before the FCC, where he was asked and to demonstrate the experiment, which failed to produce any results.

Others – academics and practitioners – tried to get Vicary’s results in their own experiments. They failed, too.  When pressed to provide proof, Vicary refused (to protect his patent application, he said).

Even the CIA looked into the matter in 1958 and concluded that “there are so many elusive variables and so many sources of irregularity in the device of directing subliminal messages to a target individual that its operational feasibility is exceedingly limited.”


The entire affair is shrouded in mystery. Nobody has seen the results of Vicary’s movie theater experiment, nor the patent that he said he was filing. When a researcher visited the Fort Lee theater, the theater manager denied the experiment that had supposedly lasted six weeks ever took place. The manager also couldn’t recall any dramatic changes in popcorn or Coke sales.

Vicary’s fate is unclear as well. Some claim that Vicary managed to pocket $4.5 million (or $45 million in today’s money) from gullible ad executives, and then disappeared. Others argue that instead Vicary’s company struggled financially and that Vicary simply faded away.

We could dismiss Vicary’s publicity stunt as a hoax if not for the position that subliminal advertising has cemented in our culture.  From conspiracy theories and naughty words in the ice cubes to subliminal self-improvement tapes, we refuse to let the idea go. Academics bring the idea back every decade or so to see whether there’s something to Vicary’s claims after all. The most notable replication attempt involved showing people a message with Lipton tea – it found that people who were already thirsty where more likely to choose Lipton over alternatives.

So, did he, or didn’t he?  And if he didn’t, what would’ve happened if he did?



That was the question we set out to answer with an experiment of our own.

The idea was simple. Take a video clip, add the subliminal message, put it up online, show it to people, measure the effect. If this set-up works, imagine the possibilities. How about YouTube videos without the bothersome pre-rolls?  Oh, the places we’d go.

Our replication attempt differed from the original in several ways. The movie goers in Vicary’s study watched an entire movie Picnic (two Academy awards); we took Picnic and cut out a two-minute clip.   

Instead of renting a movie theater, we used AYTM’s online survey platform. And instead of monitoring changes in popcorn sales on a concession stand, we asked people three questions:  which snack they would pick from a list of typical movie foods, how desirable each type of food felt to them, and how much they would pay for a bucket of popcorn, using a standard Van Westendorp price sensitivity meter.  

Our subliminal message was the same as Vicary’s. It said “Hungry? Eat popcorn” and it was printed in the same font, size, and position on the screen.

There was one problem that we had to work around. Vicary claimed that he had flashed the subliminal messages every 5 seconds for 1/3000 of a second (or 1/3 of a millisecond) on the top of the movie projection, using a device called tachistoscope. (Tachistoscope is a projector with a shutter.)  The first part of the problem is that Vicary’s claim itself is questionable – the fastest flashes that a tachistoscope could produce were only 10 milliseconds, or 30 times slower than the speed Vicary claimed.

The other part of the problem is that in regular video, it’s impossible to produce flashes that are that fast. (TV executives who considered running TV programming with subliminal messages at the time where concerned about the same limitation that has to do with the framerate of video or film.)

Instead, our “Hungry? Eat popcorn” message was visible for 30 milliseconds, which as fast as the technology allows. This is still really fast, ten time faster than the speed of a blink. Unfortunately, for an experiment such as ours, this is not fast enough, because some people might still recognize the words. (It has to do with what is known as visual afterimage, the temporary footprint on one’s retina that allows person to “see” the image after it has disappeared). We did what psychologists usually do in similar studies: right after we showed our subliminal message, we showed a series of “Xs” that masked the original message, also for 30 milliseconds. If there was any perception of the “Eat popcorn” message, the mask made it truly subconscious.

We can probably assume that Vicary’s comparison group consisted of movie goers who saw Picnic without the subliminal message.  In addition to the experimental group that saw Picnic with “Eat popcorn” and mask of X’s flashing every five seconds, we had 3 control groups. The first control group saw the plain video clip. The second control group saw just the mask, the X’s but without the “Eat popcorn” words” – we wanted to make sure that whatever result we get is not due to the flashing itself. And finally, we’ve added a third control group that we call “the explicit group” in which people saw the “Eat popcorn” words fade in once for 2 seconds.

The results?

We found nothing. We did not see a significant change in any of the metrics for the subliminal condition – not in the choice metric, not in the desirability. We controlled for hunger, for gender, for age. We excluded people who claimed to have recognized the words on the screen. We excluded people who didn’t pay attention to the screen.


To be completely sure, we ran the experiment twice. In the first set-up, we used a clip from the original movie Picnic. In the second set-up with a different group of participants, we used a recent trailer for the upcoming Pirates of the Caribbean sequel. We thought maybe the “interestingness” of content will make a difference, and the trailer was rated as more interesting than a 1957 clip.  But the subliminal message still didn’t work.

We can’t say definitively that subliminal advertising does not work. After all, there have been plenty of successful experiments with priming. And maybe one day, in some shape, subliminal ads will eliminate bothersome commercials.

But it is very unlikely that Vicary’s experiment, if it was ever conducted, had produced the sales increase that he claimed.



The myth of subliminal ads remains just that — a myth. We presented the findings at the Nonconscious Impact Measurement Forum.

With Lindsey Decker, Matt McKenna, Andres Hernandez, and Lev Mazin at AYTM