Yawn

I am convinced there is a single yawn on this planet that travels from person to person. More to the point, I believe that a person yawning is caused by them being hit bit a subatomic particle that I will call a 'yawnion'. In all actuality, there is only one (1) 'yawnion' on the planet and it travels faster than the speed of light, this is why yawning appears to be contagious. The 'yawnion' has a higher chance of hitting someone next to you than someone on the other side of the planet. However, since it is a superluminal particle it can affect someone on the other side of the planet, and your physical neighbor all very suddenly.