Did you know that yawning may be a way to cool your brain? University of Albany researchers found that our brains work more efficiently when they are cool (like a computer) and that yawning brings in cooler air and increases blood flow to cool the brain and help us to think more effectively.
Recognizing that yawning seems to be contagious, the researchers tested what might prompt a contagious yawn. When test subjects held an ice pack to their head while watching videos of people yawning, they did not yawn as much as when people held a warm pack to their heads. Breathing through the nose rather than the mouth also cools the brain more effectively.
They also proposed that we are biologically hard-wired to yawn to stay alert and protect us from danger. And, when one person yawns, others may feel the need to yawn as well as a way to promote group vigilance in the face of potential danger.
So, if someone yawns when they are talking to you, take it as a compliment because they may just be trying hard to pay more attention to you!