Secondly, anger might be classified as exciting or calm. The exciting anger has greater tension during the period of the emotion proper. There is usually less co-ordination and greater intensity of feeling which may be either pleasant or unpleasant. The motor reactions are more prominent than the mental reactions. On the other hand, calm anger usually has a longer observable fore and after-period of the emotion. Mental processes are intensified, the motor expression is correspondingly less. Anger may be classified according to its function. The emotion may be merely an end in itself. It relieves the tension of unpleasant feelings. It is purgative in its effect in removing an unpleasant mental situation. The underlying purpose of such anger is not to increase volitional action, in fact, it may disturb co-ordination to any purposive end. This type serves primarily to remove the tension of unpleasant accumulations of feelings in some act of expression. If successful in its purpose, it may have an indirect hygienic effect on mental action. Further, anger may be of a kind which intensifies volitional action, accomplishes work, and serves the end of survival. A residuum in mental attitude and emotional disposition follows, which has possibilities either of morbidity or a source of energy which is sublimated into work. Anger may be classified genetically on the basis of sentiments which are violated in its origin. Anger which springs from a thwarting of desires is primary in its origin. This is the usual type of anger of young children and animals. Anger which has its source in the self-feelings, such as the sentiments of honor and self respect and in social feelings, of injustice, of fairness, are genetically later in their development.