The contagious yawn, once unleashed, cannot be contained.
Did you know, there's research to suggest that the more empathetic you are, the more likely you are to catch someone's yawn? And did you know, even dogs can catch your yawn? If you're part of their social pack, it just may happen. Scientists are gaining more insight into why we yawn in the first place. I've read articles on how the brain heats up more during times of transition or fatigue, and yawning cools the brain. This might explain why some people yawn more just before experiencing a migraine or seizure -- these are times of transition. Cool stuff.