What you didn’t know about yawning

“We can put a man on the moon, but we do not understand what the function of yawning is,” Gary Hack University of Maryland School of Dentistry in Baltimore http://news.nationalgeographic.com/news/2011/11/111115-yawning-mystery-brains-sinuses-health-science/ Have you ever experienced yawning so much that tears roll down your face? Do you yawn from boredom, lack of sleep, or as nonverbal communication?…