Yes, it's a mystery, yawning seems to be very contagious...(Sparky, about your yawning picture, I'm reading a book about the human body. In the chapter on sleep, it talks about yawning. It says we are all hard-wired to yawn sympathetically whenever we see anyone else yawn. No one knows why. And no one knows why we yawn, either. It obviously doesn't make us any less sleepy.)