Why Do We Yawn and Is It Contagious? What is the main cause of yawning?
To allow the brain to cool
A recent study has shown that yawning helps the brain cool down and allows it to work better. When the working temperature of the brain exceeds the optimal one, the brain yawns to cool it down.
Taking in more oxygen
One theory states that people yawn to bring in more oxygen to the lungs in order to breath better. However, other studies have shown that breathing in more oxygen doesn’t reduce yawning. This puts that theory to question.
Too much information
This theory is a combination of the ‘cooling the brain’ theory and the boredom theory. If a person receives too much irrelevant information during a boring lecture for example, then his or her brain might need to cool down a bit.
If one is receiving irrelevant or boring information, his or her brain might take a chance to rest for a bit and so yawning might happen. In other words, boring information can lead to yawning.
When you need to sleep
This is pretty self-explanatory and everyone has experienced this before. (See How to Have a Good Night Sleep?)
Something more interesting is happening somewhere else
We sometimes yawn when we believe that what we are doing right now might be less interesting that what’s happening somewhere else. Again this supports the theory that yawning happens when we get bored.
Sometimes yawning begins with one person and infects the rest of the group. The brains of the group in such a case unconsciously establish a rapport with the first person who yawned.
We all have cells called ‘Mirror neurons’ that allow us to experience the feelings of others. When we see someone yawning, our mirror neurons fire up resulting in wanting to yawn.
Nobody has agreed on anything yet
Yawning is still a puzzling behavior for scientists. While so many theories are available, none of them are considered an absolute fact.
Stress and anxiety could cause yawning
Both stress and anxiety can lead to increased brain temperature and as a result yawning could happen to maintain temperature balance and cool the brain down. This might be the reason some Olympic athletes yawn before a race. (See The Body Language of Anxiety)
We yawn when we are tired
Several studies have shown that we yawn when we are tired. Yawning in such a case might be the brain’s own way of getting in more oxygen to the body and improving its functions.
Increase blood flow
The movement of the jaw that happens while yawing increases the blood flow to the face, neck and head.