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Yawning, a Common Contagion

Illustration of a grandpa, baby, and cat yawning in the sun

Written by Peter Hong
Illustrated by
Angela Lin

We all know the sudden feeling of drowsiness and an urge to strongly exhale. Yawning happens countless times throughout the human lifespan and often doesn’t warrant a second thought. The act of yawning is commonplace, but most of us can’t explain why it happens! Every function of your body has a purpose, from eating to breathing, but what about yawning? Despite it being a common bodily function, it’s rarely part of any school curriculum, and not many people can explain the phenomenon.

Let’s dive into what yawning really is. Yawning is the involuntary opening of the mouth followed by a deep inhalation and exhalation. While it’s frequently assumed that we yawn when we’re bored or tired, scientific research suggests that there’s a lot more to it!

Some researchers speculate that yawning is a response that keeps us focused and aware. When you yawn, areas in blood vessels called the carotid arteries become stimulated, leading to increased blood flow in your head. This helps to promote attention and awareness. Additionally, it’s also been shown to help regulate brain temperature and cool it down when it gets too warm! A study found that people yawn more often when they’re hot than when they’re cold. You might have even noticed that you yawn more often in the summer than the winter!

The reason it is possible to test yawning responses is because people often yawn in response to others yawning. Even the thought of yawning can provoke this! In writing this article, I myself have yawned numerous times despite it being in the middle of the afternoon.

The reason behind this relates to high empathy; people who yawned more often in response to audible yawning scored noticeably higher on standard empathy evaluations. This is why it makes sense that you yawn after a friend or family member does! This phenomenon is also seen in certain apes and monkeys as an indicator of social bonding.

The length of a yawn also has a scientific basis behind it. Yawn duration is proportional to the number of neurons you have, which are the cells of our brains. Therefore, the length of yawns can broadly indicate brain weight. After further investigation, researchers have found this to be true in numerous mammals other than humans!

Overall, even though yawning is associated with being bored and tired, it’s actually a very intuitive process! So the next time you yawn, pay extra attention and see what your yawns can tell you!

If you yawned while reading this article, check out more articles from the SCC! Trust me, science says so!