Why Do We Yawn?

January 20th 2016

Ingrid Holmquist

Prepare yourself for a yawn-worthy read. No, this subject isn’t boring; rather, even just reading about yawning could pass along the contagion of a yawn.

What is yawning?

Yawning is a way to keep our brains alert. Surprisingly, in times of stress. Some scientists hypothesize that yawning is a form of cooling down our brains so they can work at the proper temperature. Which is where stress comes in. Stress causes our brains to heat up – thus, we open our mouths wide and deeply inhale. Think of a yawn like the computer fan in your laptop. It kicks into action when it’s overheated – allowing your computer to perform at its best.

Not all yawns are created the same.

Much like we cry for different reasons, laugh in different scenarios, we yawn for different scientific reasons.

The transition yawn: Say, when you’re about to go hang-gliding for the first time or right before your first basketball state championship, you might yawn. You certainly are not bored or tired. Rather, this is your body preparing your body for a big transition. While less exciting, waking up and going to sleep fall into this category.

The sleepy yawn: When you’re bored or drowsy and you’re trying your hardest to hold back an inappropriately-timed yawn, your body is telling your mind, 'stop wandering and pay attention.'

All of the above examples of yawns are considered spontaneous yawning – but what about contagious yawning? You know, the yawning you’ve most likely been doing while reading this post.

Reading the word “yawn” is enough to make you yawn.

While all of the animal kingdom yawns, only chimpanzees and humans contagiously yawn. Children under four years old often don’t contagiously yawn and those with autism spectrum disorder or schizophrenia often do not experience contagious yawning.

A Psychology Today article found ties to the discovery of contagious yawning with a better understanding of the genes in people who have autism or schizophrenia. Elizabeth Cirulli, Ph.D., assistant professor of medicine at the Center for Human Genome Variation at Duke University, explained how yawning can break down other barriers to health questions.

“It is possible that if we find a genetic variant that makes people less likely to have contagious yawns, we might see that variant or variants of the same gene also associated with schizophrenia or autism. Even if no association with a disease is found, a better understanding of the biology behind contagious yawning can inform us about the pathways involved in these conditions.”

Though the study of the yawn isn’t cut and dry. Many scientists today disagree with the answers to why we yawn and why they are contagious. Until the great phenomena are agreed upon – revel in one of the human bodies strangest evolutionary traits.