Y is for Yawn.
Is it true that yawns are contagious?
Research shows that at least 50% of people will catch a yawn when seeing someone else yawn or when reading or talking about yawns. Researchers also show a link between those that can "catch" a yawn and the ability to have empathy for others. Read about it here. And there are other "experts" who believe that it has nothing to do with empathy. So, basically, yes, the experts believe it's contagious!
Exactly what is involved in a yawn?
Obviously, it involves your mouth and jaw. When air goes into the lungs, the abdominal muscles flex, and the diaphragm is pushed down. When the lungs are at or near capacity, air is let out. Did you know it can actually increase your heart rate up to 30%?
Does yawning mean you're tired?
Not necessarily. Certain people yawn at odd times such as an Olympic athlete who yawns just prior to his or her event. In this case, it is stress relief or anxiety creating the yawn. Instead of being tired, it could also be your body's method of keeping the brain at the right temperature.
What is the one thing that is clear about yawns?
That scientists don't agree about the real reason WHY we yawn. This much is clear.
And one last tidbit...
People tend to yawn less when they are in a cold room.
I bet you yawned at least once while reading this! I did!