Contagious Yawn

You might not know it, but yawns are contagious. That's right. if you subconsciously see someone yawn, you will find yourself yawning. I'm willing to bet that a great number of the yawns that you have ever made are because you subconsciously saw someone else do it. If you dont believe it, you can just try it out on yourself or someone else. for example, go talk to someone and fervently slide in a yawn while you are in the middle of speaking with them, and you will see that they will not be able to hold back a yawn (considering that they dont know what youre up to).

There is also that new pepsi commmercial that carries this theme. One guy yawns, and another guy sees him, and so on and so forth until someone giving a public adress begins yawning and then people who are watching it begin yawning. The commercial is brought to and end when the pepsi product is drank by people and the yawning is stopped. "Wake up people" is the motto that is designed to show that this pepsi product will wake you up, hence the "wake up" part.