The Weird Science Of How We Smell Different When We Watch Movies

Audiences emit particular chemical signatures when watching different kinds of scenes.

The Weird Science Of How We Smell Different When We Watch Movies
[Photo: Heath Korvola/Getty Images]

There are two kinds of movie science: There’s the kind that’s debunked by sites like Insultingly Stupid Movie Physics (victims thrown backwards by bullet impacts, visible laser beams, glass windows that shatter without cutting the person shattering them), and the kind done by real scientists who are studying movies. And two new studies show just how serious these people are about their research. One tells us why we like trashy movies so much, and the other proves that a movie can make its audience smell like trash.


The most amazing thing about the latter study, published in Nature, is that somebody thought to do it at all. By monitoring the levels of CO2 and volatile organic compounds in a movie theater, the researchers discovered that a particular movie elicits a particular smell from its audience, and this “smell signature” changes from scene to scene. What’s more, that signature is reproducible. Another audience, in a different cinema, watching the same movie, will exude the same mix of chemicals from their breath. Theoretically, you could tell what movie is being shown by sampling the theater air.

Animals give off different chemical compounds, and these chemicals can act as signals, although, say the researchers, the precise role of human pheromones is still unclear or at least undetected. In an experiment designed to track the chemicals breathed out by a crowd in response to emotional and sensory stimuli (movies), the researchers directed air into the theater through floor vents, and out through ceiling vents. The exhaust was tested with a mass spectrometer to look for over 100 trace gasses.

[Photo: danr13/iStock]

The result, across 9,500 cinema-goers watching 108 screenings of 16 different movies, was a reproducible chemical signature that varied scene by scene. Further, by categorizing the various types of movie scene (suspense, comedy, etc.) the researchers were able to match a chemical mix with certain emotional events.

The theory is that we communicate our state through chemical signals, and the response to movies is the same as our response to real situations that elicit the same emotions. One consequence of these findings is that future studies that measure the chemicals in our breath should take into account our state of anxiety. Another, more important for most of us, is that the chemicals given off by the crowd affect us, which means that watching a movie in a crowded theater is a very different experience to watching one alone. This might explain why movies can seem funnier or scarier when viewed with a crowd.

The other movie-based study published this month tells us why we like trashy movies so much. It’s all to do with irony. We identify trashy movies as cheap, which puts them in the same space as low-budget movies. But the typical audience member for a trashy movie is also a lover of art cinema, a “well-educated cultural omnivore,” according to the published paper. Why, then, are we happy to watch a couple of hours of trashy cinema when we wouldn’t go near a trashy art exhibit or read a crappy book?

To find out, the team, from the Max Planck Institute for Empirical Aesthetics, first determined what a trashy movie actually is. Study respondents said that the “cheapness” was the key ingredient. But this still doesn’t explain why we would favor a cheap movie over, say, a cheap TV soap opera.


The clincher might be the way we see these movies. The “well-educated cultural omnivore” sees these movies as a “positive, transgressive deviance from the cinematic mainstream.” That is, we’re rebelling against the culturally accepted norm of what a good movie is.

This might explain why a movie like Snakes on a Plane failed so badly. Not only did it look big-budget, it had a proper movie star (Samuel L. Jackson) in it, and seemed engineered to cash in on the trash movie phenomenon. That is, a mainstream trashy movie will fail, precisely because it’s mainstream. That’s a nice thought for elite cultural omnivores, because it means that Hollywood can never (intentionally) muscle in on what they perceive to be a nerdy niche.

One is left to wonder, in the light of these two movie-based studies, whether their science could be combined. Do trashy movies have a unique kind of chemical signature? And if so, just what does a Sharknado audience smell like?

Have something to say about this article? You can email us and let us know. If it’s interesting and thoughtful, we may publish your response.

About the author

Previously found writing at, Cult of Mac and Straight No filter.