[The concept of aggression in psychology and psychotherapy].

Aggressiveness is one of the basic characteristics of human beings. It can be defined as a relatively constant individual disposition or group characteristic manifested by the frequency, intensity and mode of aggressive behaviour. Aggressiveness has an inborn basis but its frequency, intensity and form are acquired during life and can therefore be influenced by the environment, i.e. also by training and psychotherapy. With regard to the genesis and purpose we differentiate between reflex, instrumental aggression, aggression with an end in itself and aggression resulting from affection. Psychological theories on the genesis of aggression can be divided into endogenous, exogenous and the interaction approach. The author discusses in his paper also the relationship between aggression and the type of psychotherapeutic treatment, and expands in more detail on aggressiveness and its control within the framework of Rogers' approach (person-centered approach).