Quote Originally Posted by Alep View Post
OK, how about this. Could you generalize tells? Maybe for example, why do they exist and how are they supposed to reveal something? If you can throw some science in here... Thanks
Tells exist because poker is a game that naturally gets people's emotions going. Even in low-stakes games, where the money doesn't mean anything to people, it's a naturally competitive game that brings out people's spirit of competition.

And I think everyone would agree that there are differences in physical measurements based on emotional changes. We blush when we get nervous; our heartbeat speeds up when we get excited; we might try to look bigger or more intimidating when threatened physically, or maybe make ourselves look smaller.

My point is that there are definite changes the human body unconsciously does in reaction to emotions and feelings. Poker is like anything else. This is not to say that I think it's an exact science, or that we can always know what's going on in any situation. But it does mean I believe that many players will have strong, statistically-significant tendencies. Far from all; but enough to make it worthwhile to study.

If you'd like more scientific study into this area, I recommend Paul Ekman's books; he's a noted scientist who has studied the facial expressions and body language associated with emotions.