As humans, we have this notion that people generally wear their feelings on their sleeve. This is the idea that we, the observer, can infer the feelings of other people through their mannerisms, attitude and actions. If someone is smiling, we tend to believe they are enjoying themselves. If someone furrows their brow, we assume they either do not understand something, or are thinking of something to say. Of course, people are much more complex than this, and even my examples may not be 100% true to you,...