We all do it.
On average 8 times per day in fact.
Even animals do it.
It all has to do with the brain.
The brain tends to heat up faster than any other organ in our bodies and this can be a problem because our brains function best when they are cool.
Enter yawning. Yawning is simply an effective way of cooling the brain down.
When we yawn through stretched jaws, the air travels through to our upper nasal and oral cavities and increases blood flow to the brain, cooling the blood flow at the same time. Studies have found that people with cold packs on their head yawn less than those with warm packs.
Tiredness and exhaustion tend to heat up the brain (in fact our brains are hottest at nighttime just before bed and start hearting up again when we wake up) which explains why we always seem to yawn when tired.
Why then do we often yawn when we see someone else doing it?
If you’re a contagious yawner, this might just mean you’re a really nice person.
Individuals with higher levels of empathetic understanding tend to mimic others yawning most often. To the contrary, psychopaths and children under the age of four are less likely to mimic another’s yawn, lending weight to the empathetic theory. Other theories suggest that contagious yawning is a primal method of keeping members of a group alert, and developed as an evolutionary way of communicating a ‘fight or flight’ response within a group.
So next time you’re talking to someone and they yawn, don’t take it personally – they’re not bored, their brain just needs a little cool down.