People who still go to the movies, especially those who arrive early to get seats in just the right row, put up with a lengthening barrage of commercials. These ads, for cell phones and TV shows, fast-food chains and the armed services, are loud and annoying and have surprisingly little effect on a large chunk of the audience—specifically, people eating popcorn. Popcorn, a study suggests, makes us immune to advertising.
The research, published in the Journal of Consumer Psychology and conducted by psychologists at the University of Cologne, involved sending people to a movie. Before the film started, the German test subjects were shown commercials for Tostitos, Pert Plus shampoo, Danish butter Lurpak, Korean body lotion Innisfree, and other beverages, foods, and medicines unfamiliar to them. Half the participants were given popcorn, the other half a sugar cube. One week later they were invited back to the lab and shown images of various products. The sugar-cube moviegoers had a clear preference for the products they’d seen advertised, while the popcorn eaters didn’t. In other words, the ads hadn’t stuck with them.
What accounts for popcorn’s seemingly talismanic power? The researchers posit that it’s not popcorn at all; it’s chewing. Ads can be masterpieces of visual invention, but one of their most persuasive mechanisms is repetition—that’s why marketers find ways to say the name of a product over and over. Experiments going back to the late 1960s have documented what psychologists call the “mere exposure effect.” Simply having seen or heard something before predisposes people to liking it. And the way consumers familiarize themselves with something new is with their mouths.
When people read, they tend to mime the act of speaking. Even if they’re not saying the words out loud, the brain simulates the corresponding muscle movements of the throat and mouth. Sascha Topolinski, one of the popcorn study’s authors and a neuroscientist at the University of Cologne, calls this “covert pronunciation simulation.” The same thing happens when we hear something—the name of a new product, for example. Chewing, however, disrupts the process by monopolizing the speech muscles (unlike eating a sugar cube, which dissolves on its own), effectively drowning out any subvocalization and, with it, the process of familiarization.
“What we found was that if you prevent the mouth from simulating the pronunciation by chewing, you don’t get repetition effects,” Topolinski says. In a similar 2009 study he presented gum-chewing subjects and those without gum with a series of nonsense words. When the subjects were shown the words again at a later date, those without gum liked the nonsense words they had seen earlier more than the new words, while the gum chewers had no preference.
If the popcorn study holds up, it has ramifications not only for movie ads. On the one hand, the idea that eating inoculates people against unconscious persuasion is empowering: If you want to gird yourself against the claims of a con man, start chomping on some popcorn (or celery, if you’re into that kind of thing). But there are plenty of settings in which people are trying to absorb new information while eating—the working breakfast, the client dinner, the lunch consumed resentfully at one’s desk while trying to catch up on e-mail. Those might all be occasions in which we’re not taking in information as easily as calories. Unless, of course, we’re willing to talk, even silently, with our mouths full.