Interesting Facts You Didn't Know About Yawning

You may not believe it, but yawning is one of the most highly contested bodily functions of the 20th and 21st centuries. Scientists think they know why we yawn, but they’re not really sure. In fact, every few years a new study is released that claims to have unveiled what is the cause of yawning and contradicts previous research. It’s an equally fascinating and frustrating phenomenon.

Why do we yawn? Some researchers believe that we’re cooling down our brains and giving ourselves the perfect bodily temperature to focus, while other scientists think that we’re cleaning out our bloodstreams. We’ll take a look at both of those theories and a few more on this list of facts about what happens to the body when it yawns.

One of the biggest questions concerning yawning is “Why do I yawn when I see someone yawn?” It can be a frustrating reaction, but it might also mean that your brain is more suited to being empathetic than someone who didn’t yawn. Maybe. Who knew “Why do I yawn” would be such a loaded, and complicated question?

On this list of things you didn’t know about yawning, we’ll dive into the health risks that come along with yawning, and even what your pet is trying to tell you if it yawns. Make sure to leave us a comment if you found yourself involuntarily yawning while reading this list. If you didn’t, you may want to have a chat with your local neurosurgeon.
Photo: Petra Bensted / via Flickr / CC BY 2.0

  • Yawning Cleans Your Blood
    Photo: larkery / flickr / CC-BY-NC 2.0

    Yawning Cleans Your Blood

    It turns out that there's not a simple answer for why we yawn. When we're yawning, our body is doing ALL OF THE THINGS, including bringing more oxygen into our bloodstream while at the same time cleansing it of carbon dioxide.

    It's almost like our bodies are creating a filter and our mouths are the giant opening. 

  • Yawning Is (Kind of) Contagious
    Photo: flickr / CC0

    Yawning Is (Kind of) Contagious

    Short answer: sort of? The long answer is actually pretty fascinating. According to scientists, yawns are contagious in about 60-70 percent of people, and this was discovered by testing susceptibility to contagiously yawning with performance on a self-face recognition task, several theory-of-mind stories, and on a measure of schizotypal personality traits. 
  • Animals Can Catch a Yawn

    Proving that we're more closely related to animals than we think, most animals can succumb to contagious yawns just like we do. In a series of experiments carried out dogs, their owners, and strangers, scientists tested whether or not dogs could catch a yawn from someone.

    Scientists discovered that dogs could catch a yawn from someone, but it was less likely if the yawn was disingenuous

  • Yawning Cools the Brain
    Photo: flickr / CC0

    Yawning Cools the Brain

    It turns out that one of the many functions of yawning is to help "cool down" our brains. Interestingly enough, our yawns aren't affected by the seasons, or a heat wave, but rather the "optimal thermal zone of around 20°C [68°F]."

     Jorg Massen and a team of scientists discovered that yawns cool the brain in order to achieve "arousal and mental efficiency," and that contagious yawning can improve group alertness. 

  • Yawning Might Be Evolutionary
    Photo: Wikimedia Commons / CC-BY

    Yawning Might Be Evolutionary

    Yawning wasn't always just a way to keep our brains in the optimal cool zone. Prior to humans taking an evolutionary step into using tools, yawning had a completely different function than it does now.

    A common theory about yawning, or a comyawn theory, if you will, is that ancient humans used to yawn as a way to bare their teeth and intimidate enemies. It also might have been our internal clock's way of telling us it was time to change activities. 

  • When You Yawn, Your Whole Body Yawns
    Photo: Metaweb / CC-BY

    When You Yawn, Your Whole Body Yawns

    When you yawn, you don't just open your mouth and exhale air. In fact, your entire body has a response to your brain trying to cool itself off. When you begin yawning, the muscles around your skull contract and stretch and you take in ambient air, and then your body begins secondary behaviors such as throwing your head back and stretching out your arms, which also act as ways to cool off your body.