Yawning Helps The Brain

Our nervous system performs numerous mysterious acts, which we may not understand, but accept and appreciate nonetheless.  One example is yawning.  We do know that this happens more when we are tired and appears to be contagious, so to speak, but new research has found that it may also play a role in temperature regulation of the brain.  It seems that this innate behavior, which is found in all animals with a spine, has a multifaceted purpose.  So the next time you yawn, remember not to stifle or block it, like we seem obligated to do, and allow your body to do what it knows best.

http://www.medicalnewstoday.com/releases/234707.php
http://slices-of-life.com/2011/08/01/why-are-yawns-contagious-and-what-to-about-it/