This publication is one of the few professional books that attempts to explain the psychological concept of the locus of control into a theoretical as well as research aspect. The Czech equivalent for this term is the 'místo kontroly'. The essence of this concept is the belief of man in what generally controls the reinforcements (rewards and punishments) that he receives. 'Internists' (internal locus of control) have a higher need for independence, better cope with stressful situations, they are less ill and live longer. 'Externalists' (external locus of control) often experience feelings of helplessness, use passive strategies for coping with life, or more often addicted to alcohol or drugs.