Professor Vernon discusses in detail the scientific status of psychoanalytic and other 'depth' theories of motivation, the value of different types of psychotherapeutic treatment and counselling, the influence of upbringing on the development of personality, and the effectiveness of projective techniques. He also examines the reasons for the highly variable results obtained with personality tests and questionnaires.
As well as providing a balanced review of theories of personality and of various types of test, this work made a fresh contribution to developing improved techniques of assessment.