Why Did I Just Yawn?

Have you ever been in the middle of a conversation with someone, you’re really engaged in it, and out of nowhere you just yawn? It’s like, I’m not trying to be rude, I swear I got a good night's sleep (or at least a decent sleep), but I can’t help but yawn. That strange bodily function is something we rarely think about, after all, we can’t really do anything about it. But here to help us understand a little bit more about this curious habit is Dr. Andrew Gallup, Assistant professor of Biopsychology at the New York Polytechnic Institute.