I haven't yawned for 12 years. Now my sister wants scientific sources on my claims why you should not yawn and why yawning is bad! I am my own scientist and have come to my own conclusion myself because I can relate to my life before when I actually used to yawn sometimes compared to now being one of the few non-yawners in the world. Google is not helpful at all. All results are pro-yawn. Help me with links!