If you've been up all night, it's pretty obvious:you're tired. But your yawn says more.
1. You like someone
Yawning is contagious and the more empathy you can muster for someone, the more likely you are to start yawning when the other person does.
2. Your brain needs cooling
In the search for a scientific explanation for yawning, it was discovered that a yawn provides some air for your brain. This ensures that you get just that little bit of extra energy. That could explain why we yawn more when we are tired, your brain can always use some fresh air and extra energy.
3. You have a big brain
The length of your yawn may say something about the size of your brain. The longer your yawn, the bigger your brain would be.
