Why Do We Yawn?

People yawn when they are getting tired typically, but why?

The restorative process of sleep lowers the brain entropy by lowering the biological processes and increasing airflow. As the day pushes on, you literally build pressure. For the same reason you get shorter over the course of the day.  You create more disorder in your brain as the day wears on. The yawn is essentially a deep breath that maximizes the airflow and decreases the brains temperature and pressure.

This is why breathing pure oxygen doesn’t eliminate yawning. It doesn’t address the problem.

People also yawn when they are bored. Can we explain this?

If we go back to William Bates’ book on eyesight, boredom actually creates mental strain. And we know that mental strain changes your vision. And we know that vision changes are just a symptom of brain entropy. And your yawn is just a way to counteract all that.

If that’s true, why are yawns contagious? Or are they?

It’s safe to say that they are contagious. But the jury is still out as to why. I was first going to say that it’s a reflex after seeing someone else yawn, but blind people do it too-when they hear someone yawn.

So just like when you see someone drinking, you consciously or subconsciously do a self check to see if you’re thirsty. When you see [or hear] someone yawn, you do a self check regarding the entropy or temperature of your brain. If it’s too hot or chaotic, you yawn.

People with Autism are less likely to yawn contagiously. 

Because that’s what makes them Autistic in the first place. They operate with higher levels of brain entropy. It’s the same reason they they die so much sooner. They are so far from their equilibrium point, that they experience time in a completely different manner. Well not completely,  just shorter. It’s also why they are so much more likely to drown. 

So no, they are probably not going to yawn contagiously. Because they have built an identity around the pressure that the yawn equalizes.


  1. https://kids.frontiersin.org/article/10.3389/frym.2017.00052
  2. https://kidshealth.org/en/kids/yawn.html
  3. https://www.healthline.com/health/why-do-we-yawn#see-a-doctor
  4. https://www.ncbi.nlm.nih.gov/pubmed/3120687
  5. https://www.psychologytoday.com/us/blog/the-athletes-way/201403/why-is-yawning-so-contagious
  6. https://www.factretriever.com/autism-facts