Sniffing Is Contagious, Like Yawning and Laughing

Humans are social animals. As a result, we do a lot of things just because everyone else is doing them. Sometimes, you might find yourself yawning or laughing along with other people, even if you might not necessarily want to (or even if you don't know what everyone is laughing about in the first place). In 2014, researchers performed an experiment to find out if sniffing was another example of unconscious contagious behavior. Here's what they found.

This Science Passes the Smell Test

For the study, a research group from the Weizmann Institute of Science in Israel had 27 subjects watch a movie in a stainless steel, odor-free room to investigate mirror sniffing — that is, the act of mimicking someone else's sniffing patterns. The movie they chose? The 2006 film Perfume, a thriller about a perfumer-turned-murderer that happens to include 28 "movie sniff events" (MSEs) within the first 60 minutes. The researchers hooked up each of the participants to a nasal cannula attached to a spirometer and told them that they were being used to calibrate "physiological recording devices" — the movie, they said, was just to keep them from getting too bored. Then, the researchers measured how often the participants' sniffs coincided with an MSE.

So, did the subjects mimic the movie sniffs? According to the research team, the answer was yes. Despite the fact there was no odor in the room, participants tended to sniff along with the characters in the film, especially when they heard a sniff but didn't see the object being sniffed.

The Nose Knows

In the study, the researchers write, "The potential value of a such a response is clear, because it would direct awareness towards valuable information such as danger, food, or a potential mate [...] However, if we hear someone sniffing without a visual target, this implies that there is 'something important in the air,' and we had better find out what it is." Smell is the most ancient sense we have, so it should almost come as no surprise that our basic instincts make us sniff along when we see or hear someone else sniff. Laughing when you didn't hear the punchline, however? We're on our own there.

Watch and Learn: Our Favorite Content About Contagious Quirks

Why Is Yawning Contagious?

Key Facts In This Video

  1. Yawning and stretching at the same time is called pandiculation. 00:29

  2. People contagiously yawn less frequently when they have an ice pack on their heads, according to research. 01:51

  3. Some penguins yawn to attract mates. 04:47

Are Your Emotions Contagious?

Key Facts In This Video

  1. Humans mimic each other's facial expressions, postures, and elements of speech without realizing it. 00:18

  2. Human brains have "mirror neurons", neurons that fire when an action is performed and when it is observed. 00:46

  3. Some neuroscientists believe mirror neuron theory has been over-generalized. 02:34

Written by Curiosity Staff May 22, 2017

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