A trip to the movies almost always comes with a bucket of popcorn. But according to a psychology study, that familiar movie snack could be doing more than keeping your hands busy and mouth full. Researchers found that chewing popcorn while watching commercials may actually weaken the persuasive power of advertisements for unfamiliar brands, making moviegoers less likely to choose those products later.

You settle into your seat, grab a handful of popcorn, and the commercials begin. For most people, it's an automatic routine. The lights dim, the trailers roll, and the popcorn disappears by the handful. But what if that simple act of chewing is changing the way your brain responds to advertising?

A 2014 study published in the Journal of Consumer Psychology by Sascha Topolinski and colleagues from Germany's University of Wuerzburg suggests exactly that. Researchers found that people who eat popcorn or chew gum while watching commercials are less likely to be persuaded by advertisements for new or unfamiliar brands than people whose mouths remain relatively still.

What the researchers wanted to understand

Advertising often works because of a well-known effect known as the ‘mere exposure effect,' which suggests repeated exposure makes a brand feel more familiar and, over time, more likable. The researchers wanted to investigate whether this process depends partly on subtle movements inside the mouth.

They proposed that when people hear a brand name, they unconsciously simulate its pronunciation through what psychologists call subvocal articulation, a kind of silent inner speech.

As the paper explains, silently simulating the pronunciation of a brand name is an important mechanism by which advertisements influence consumers.

If chewing interferes with those silent speech movements, then the persuasive effect of the advertisement could also weaken.

How the study tested the idea

The researchers conducted two experiments. In the first, 188 participants watched advertisements featuring unfamiliar brands. Some participants ate popcorn; others chewed gum, while a control group sucked on a sugar cube, which occupied the mouth without requiring continuous chewing.

A week later, participants made choices involving the advertised products. The results showed a clear pattern.

Those who had eaten popcorn or chewed gum were significantly less likely to choose the advertised unfamiliar brands than those in the control group.

To confirm the findings outside the laboratory, the researchers conducted a second experiment inside a real movie theater with 96 participants. Once again, eating popcorn reduced the advertisements' influence on attitudes toward the new brands.

Why chewing changes the brain's response

According to the researchers, chewing creates what they call oral interference. Instead of silently rehearsing the sounds of a new brand name, the muscles involved in speech are already occupied with chewing. The paper explains oral interference sabotages the repetition-based advertising effects.

In other words, because the brain cannot as easily rehearse the unfamiliar brand internally, the advertisement loses one of the psychological mechanisms that normally makes it effective.

Does this happen with every advertisement?

Not necessarily. The study focused specifically on new and unfamiliar brands rather than products consumers already knew well.

Well-established brands benefit from years of repeated exposure, emotional associations, memorable logos, packaging, and prior experience. The researchers suggest that the chewing effect is most relevant when advertisements rely on creating familiarity with a brand people have never encountered before.

Alternative explanations why this happens

The researchers also considered several alternative explanations for their findings but found little evidence to support them. One possibility was that eating popcorn distracted participants or made the experience more enjoyable, reducing the impact of the advertisements.

However, this explanation was weakened by the fact that chewing a tasteless gum, which was neither enjoyable nor distracting, produced the same reduction in advertising effectiveness. Another possibility was that participants simply remembered the advertised products and chose them based on conscious recognition. The researchers argued this was unlikely because participants watched several filler commercials and were tested a week later, and previous studies have shown that oral interference affects implicit memory and preferences while leaving conscious recognition intact.

They also examined whether visual elements such as a product's packaging, color, or shape influenced the results more than the brand name itself. Their findings suggested otherwise. In one experiment, participants made choices using only brand names, without seeing product images, ruling out visual cues. Moreover, the researchers noted that chewing affects the mouth, not the eyes, making it unlikely that oral interference disrupted visual processing. They concluded that it was the mental processing of brand names, rather than product appearance or conscious memory, that was disrupted by chewing, thereby reducing the persuasive effect of the advertisements.

What this means for moviegoers and marketers

The findings suggest that one of cinema's most iconic snacks may unintentionally reduce the effectiveness of the very commercials shown before the movie starts. For consumers, it could mean they're slightly less likely to develop a preference for unfamiliar brands simply because their mouths are busy chewing.

For advertisers, the study raises an interesting challenge. Movie theaters are popular places to introduce new products, yet the audience's favorite snack may interfere with one of advertising's basic psychological mechanisms.

While popcorn certainly doesn't make advertising ineffective altogether, the study suggests it may weaken one subtle process that helps new brand names stick in consumers' minds, making those movie snacks more influential than they first appear.