It strikes without warning. Your head tilts back, your jaw drops down, and you take a long and exaggerated inhale. You also probably get a good stretch in, too.
One of the most misunderstood functions of our bodies is the yawn.
Often, we yawn because we are tired. We yawn when we’re tired so that we can stretch out our muscles and relieve some of that lactic acid build up that collects when we sit still for too long. We know a little about the science behind the yawn -- but why do we yawn whenever we see *someone else* do it? Especially when we are not tired?
Following the Yawn
According to studies conducted by Duke University on this topic, 300+ subjects were monitored and asked to watch a 3 minute long video filled with people yawning. Over the course of that 3 minute video, viewers yawned between 0 to 15 times.
The reason this yawning-by-association took place so dramatically? --a phenomenon called “contagious yawning.”
“Contagious yawning is a common, but poorly understood phenomenon,” says Doctor Steven Platek in his study on contagious yawning. The results of his study “suggest[s] that contagious yawning may be associated with empathic aspects of mental state attribution and are negatively affected by increases in schizotypal personality traits much like other self-processing related tasks.”
Translation? The more empathetic of a person you are, the more likely you are to yawn with someone.
But Why Exactly Is Yawning "Contagious"?
We often try to avoid eye contact with people who we see yawning. We avoid looking at them because we know that if we look at them yawning --we for some reason will do the same. Why? Why do we yawn just by watching someone else do it? The answer has several theories (like the one given above) --but the truth is that when it comes to contagious yawning…
…we simply don’t know.
Many still think that the reason you yawn is because you are tired, and a yawn is your brain's way of informing you that you should seek sleep soon, similar to the light on your car’s dashboard coming on telling that you are running low on fuel.
Another theory as to why we yawn, according to the latest hypothesis, is that we yawn so that we can cool down our brains. As you can imagine, our brains work all the time and at unimaginable speeds, meaning that the brain heats up quite often. In an effort to cool down, some theories suggest that when we open and stretch our jaws wide, we are increasing blood flow up to our brains, and that deep inhale is an effort to cool down the surges of blood passing upwards into the skull --effectively cooling off our brains.
Like many other mysteries in our body, the yawn is not as simple to understand as many of us may think.
“Contagious Yawning May Not Be Linked to Empathy; Still Largey Unexplained” Duke Health; News & Media. 2014.
"Contagious Yawning: The Role Of Self-Awareness And Mental State Attribution." Cognitive Brain Research. 2003.
Ellis, M.. "Do We Yawn To Cool Our Brains?." Medical News Today. 2014.
Disclaimer: This article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Seek the advice of your physician or other qualified health provider with questions regarding a medical condition. Do not disregard professional medical advice or delay seeking it because of something you have read here. This article is for general information only.