Anger happens when situational infringed your interests have been violated by the psychological border. It also occurs when we are prevented from doing what we have begun. These are two natural mechanism, they are all peoples of the world. Scientist Paul Ekman fact witness. In these two cases, the anger is adequate to the situation and serves as a person in achieving its objectives to obtain desired and defend their interests.
Sometimes anger, inadequate situation. For example, nobody bothers and isn't anything, and the man takes away angry. Or a person touched lightly, and it exploded, as if it hurt. It's the anger pent arising and depressed for a long time. During therapy he is released and clients note that experiencing anger is easier, and for no reason it occurs less frequently.