A yawn is a natural reflex that causes air to be inhaled and the eardrums to stretch. It is commonly accompanied by stretching, which is referred to as pandiculation. It occurs in humans and many animals. It commonly occurs when a person is tired, stressed or bored. We have all heard that yawning is contagious (you might even be yawning reading this), so let’s take a look at what causes people to yawn.
What causes yawning?
As with many of our bodily functions, scientists do not know exactly what causes yawning. There are probably multiple different reasons why people yawn, but let’s take a look at some of the best theories. One theory suggests that we yawn because we actually want to stretch and/or to keep alert. Another suggestion is that yawning is a way of controlling brain and/or body temperature. Yet another theory is that yawning is controlled by the chemicals in the brain responsible for mood and appetite.
Contagious yawning occurs when you see someone else yawning or by thinking about yawning. It is believed to be linked to our ability to be empathetic. Interestingly, children with autism do not respond to another person yawning.
Did you know?
One of the most popular beliefs is that we yawn when the body contains a higher level of carbon dioxide than normal and requires a influx of oxygen. However, studies have shown this to be untrue.
Contagious yawning has been observed in dogs and chimpanzees.