Quote Originally Posted by Dr. Casey
People feel compelled to make sure people know what they're feeling, so they smile rather than just take the risk of letting others assume what they're feeling.
I disagree. Smiling is a reflex that most people have when something occurs to make them happy or laugh. Occasionally people will try to do a fake smile, and in that case they may well be insecure of something. But you can't just generalize on much-used social reflex.