Yawning is contagious

Yawning is contagious. Even thinking about yawning is enough. In fact, there's a 50% that you're about to, or just did, yawn.

 Yawning is contagious - even thinking about yawning is enough. After reading this fact, there is a 50% chance you will yawn. 

Research shows that 11-week-old fetuses yawn. Yawns become contagious to people between the first and second years of life. When one person in a group yawns, over half of the people in the group will yawn within 5 minutes, and the rest will at least be tempted to yawn. Even animals yawn when they see another animal yawn. The average duration of a yawn is about 6 seconds, and guys yawn for longer than girls.