I learned that yawning is a unique breathing act, which is different from the usual practice of breathing. During yawning, the mouth involuntarily opens due to the spasm of mastoid muscles. These spasms, without your permission, force you to take a deep breath. It also involves many other muscles of your body, such as abdominal muscles. Lung ventilation increases, sending oxygen to the brain. Extra blood is pushed from the liver and spleen to the brain stem. During yawning, intellectual activity stops and for a moment we cannot think. We usually start yawning when we are very tired, before sleep, when we are too excited, or extremely serious.

There is a yawn center in our brain that makes this act a reflex like coughing or swallowing. The yawning reflex is very contagious, forcing people to imitate it. This phenomenon even has a fancy name: alolomimea. “The yawning reflex has a good memory,” a German professor, Professor Knoxblat, once told me. Yawning can be easily conditioned to become a bad habit. If you fight the urge to yawn, it will return in a similar situation. Yawning is what your body develops to get a “time out” to recharge for a brief moment. It is a signal that we are running out of gas, it is a signal to rest.

This is a great compensatory mechanism, without which we would drop into sleep suddenly without warning, as in patients with narcolepsy. What is the point of this story? We should not interpret it negatively. It is not a signal about somebody else’s stimulus value. It is a signal to yourself that you are very tired. Next time, try to get a good night’s rest before an important meeting, so you will not be ashamed when it happens.