5. Yawns Are Contagious
Have you ever sat in a room with other people, and then when one person started yawning, it seemed to spread like a reflex? Alternatively, maybe you were talking to somebody, and when one of you yawned, the other person immediately followed suit.
Yes, yawns are contagious. A virus or bacteria may not cause them, but the way that they can spread can undoubtedly make them feel like they are. Moreover, there are plenty of explanations as to why yawns are contagious, all of which probably have some degree of validity.