Body Works and Quirks: Yawning

Merely thinking about or seeing someone yawn can make you yawn (you’re probably yawning right now). Most people yawn because they’re tired, but it can also happen unexpectedly and without any triggers. While yawning is typically harmless and only lasts about five to 10 seconds, when it occurs excessively it can actually be a symptom of a serious condition.

So why exactly do we yawn? And why is it nearly impossible to stifle a yawn when someone does it in front of you? Watch the video above — and read more here — to find out.

Video Transcript

- Your body has millions of moving parts working together every second of every day. I'm Dr. Jin. And in this show, we'll explain how the body works and all of its quirks. This episode will make you tired.

[MUSIC PLAYING]

Because today we're covering yawning.

[MUSIC PLAYING]

So why does this happen? Today on "Body Works and Quirks," we're going to explain just what's going on. Most of us equate yawning with being tired, but studies have found that yawning could actually be caused by your body trying to cool your brain. It's basically like turning the air conditioning on in your head. Exhaustion and sleep deprivation can increase the temperature in your brain.

[MUSIC PLAYING]

Yawning stretches your jaw, increasing blood flow in your neck, face, and head.

[MUSIC PLAYING]

Then a deep breath sends a rush of cool air to the spinal fluid and the brain.

[MUSIC PLAYING]

So we know why we yawn, we know how we yawn, but we haven't covered why yawning is so addicting. The answer is simple. Empathy. OK. It's a little more complicated than that. Humans, primates, and dogs all find yawning contagious. It's because a yawn is a common form of echo phenomena, the automatic imitation of another's words or actions, which is basically how we learn. Oh, I just love a group hug. The licking I can do without. And that's what's going on with yawning. Join us next time on "Body Works and Quirks" as we explore more of our bodies quirky ways.