The mysterious yawn — why do humans yawn? And is it contagious?
How often do you find yourself yawning during the day? Harvard Medical School published that we each yawn 20 times a day on average, but it doesn’t necessarily mean that we’re all sleep deprived.
No one is entirely sure why we yawn — it’s one of the questions that still remains a mystery. But that hasn’t stopped scientists from having a few different theories regarding the human urge to yawn.
Why do we yawn?
There are several different theories on why humans yawn. For a long time, the theory of choice was that yawning is a response to a lack of oxygen, but you might be surprised to hear that scientists have moved away from that theory.
There are a few different ideas why scientists think we yawn, per The Library of Congress.
Yawning is thought to be the body’s way of waking up the brain. Moving lots of facial muscles when you’re bored or doing less energetic activities gives your brain something to do.
As a way to protect and cool down the brain, yawning could be a response to a hot environment. Yawning draws in a large breath which could help the body take in colder air or increase blood flow in the face to cool down the blood in the head.
Another theory, reported on by USA Today, explains that we could just be mimicking each other, based on special mirror neurons in our brain.
Is yawning contagious?
The short answer is yes, seeing someone or something else yawn can make you yawn. I’m not a scientist but you won’t believe the number of times I yawned as I was researching about yawning.
One study, “Interspecific Contagious Yawning in Humans” published in 2022 in the Animals Journal explored whether yawning in different animal species could trigger a response in a human, which it did — close to 70% of participants yawned when watching a video of an animal yawning, compared to only about 29% who yawned even when the animal in the video wasn’t yawning.
Scientists are still trying to figure out why yawns are contagious.
One theory suggests that it’s an empathetic response, but the study from Animals didn’t support the idea since species closely related to humans should have triggered a higher response than species farther from humans, but they didn’t.
Needless to say, the topic of yawning is still a mystery waiting to be solved.
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