It think people yawn when they're bored, atleast I do. I'm always yawning...if I'm in class or something and my professor is lecturing If I'm not interested in the topic...I start yawning...it doens't necesarily means that I'm sleepy or anything. I hardly ever get 8 hours of sleep thats like impossible for me. I have a midterm tomorrow too. And I still have a lot of studying to do....SMH!!!!