Look at the pupils of a person. When a person is excited, attentive or interested, his pupils will dilate. After watching a little person, you can determine what's causing him concern, and thereby to calculate some features of his character.
Note that dilated pupils are almost always considered a sign of positive feelings. And constricted pupils, on the contrary, a symptom of something negative. This confirms, for example, a psychological experience, when a group of men were shown a photo of the same girl. But a single one of her pupils were large, on the other narrowed. The girl with the big eyes called soft, pretty and feminine. The girl with the small pupils identified as violent, self-centered, cold.
Trying to determine the character of a person in the face, you need to consider what culture it belongs to. For example, the Chinese protruding tongue is a symptom of surprise. Accordingly, it is erroneous to believe that this man loves to be teased or treated disrespectfully.
Asking a person a question, you can refer to the experience of neuro-linguistic programming, and depending on which direction man will take his eyes (he will take – you can spend experience, to look fixedly at one point and try to think, determine visualize it, kinetic or audiolist.
To determine the character of a man in his face might help, and the science of physiognomy. Many of the conclusions of this science can be done intuitively, for example, a man with wrinkles around the eyes (the so-called "fishtail") will be considered a truly successful women. Everything is logical: gay men women love, and the one who laughs a lot, easily earns the wrinkles around the eyes.