Asked in Yawning
Yawning

What causes a yawn and is a yawn really contagious?

Answer

Wiki User
01/06/2011

Yawns are in fact contagious as it is a subconscious effect of our mind. When yawning we gain more oxygen then we would breathing.

When the brain thinks that there is a lack of oxygen in a given space, due to the other person yawning, and you do as well, you are effectively trying to steal the oxygen from the other person to ensure you live. This also explains why dogs will yawn when a human does, and vice versa.