You sit in room with other people, watching a movie or reading a book or maybe just listening and observing the other people in a room. Then, you see one of them opens up his mouth wide and yawns. *Yawn* Next thing you know, you along with the other people in the room yawn as well. The yawning spreads like wildfire. One yawns after the other. Yawning seems pretty contagious, right? Then why do we yawn when we see other people yawn?