Why Do People Yawn?

Everyone yawns, probably several times a day - but why? What is the purpose of yawning? You'd think that with something so common and basic, scientists would have some idea about what is going on and why, but the truth is they don't. The reasons for yawning are just as mysterious as the reasons for why yawning is contagious.

The Winter 2006 issue of the Wilson Quarterly discusses “Yawning” by Robert R. Provine, in American Scientist, Nov-Dec 2005:

We know that yawning appeared early in vertebrate history and that and most other animals with backbones, including fish, turtles, birds, and crocodiles, engage it. But we don’t know why it appeared. [...] People begin to yawn early in their lives. Indeed, yawning has been observed in three-month-old fetuses — evolutionary evidence of how ancient the behavior is. It’s the contagious quality of the activity that’s especially intriguing. [...]

“Contagious yawning definitely does not involve a conscious desire to replicate the observed act,” Provine observes, but it’s possible, as some research into brain activity suggests, that someone who “catches” a yawn may be unconsciously expressing “a primal form of empathy.” Thus, contagious yawning can be linked to sociality. Some neurological and psychiatric disorders, such as schizophrenia and autism, that leave patients “deficient in their ability to infer or empathize with what others want,” apparently reduce as well their susceptibility to contagious yawning.

The idea that yawning may be related of our ability to empathize and our social relationships is very interesting. Given how fundamental yawning is to us as a species and how old it is in life on Earth, this may indicate just how fundamental the social nature of humanity is. What else about us that is regarded as purely biological may, in fact, be related to our social natures?

 

Read More:

• What is Evolution?
• What is Science?