Clinical psychologists deal with the study, diagnosis and treatment of abnormal behavior. They are trained to diagnose and treat problems ranging from the everyday crises of life– such as grief due to the death of a loved one– to more extreme conditions, such as loss of touch with reality. They explore the relationship between psychological factors and physical diseases. For example, they are interested in how long term stress can affect physical health. In addition, most clinical psychologists are trained to conduct research in emotional and behavioral problems, such as mental illness, delinquency, mental retardation, alcoholism, marriage adjustment and so on. They are mainly employed in mental hospitals, institutions for mentally retarded, prisons and private practice clinics.

In clinical psychology, often three specialists work together; psychiatrist, psychologist and social worker.

Physiological Psychologists

Closely related to experimental psychology is the smaller but rapidly growing area of physiological psychology. The physiological psychologists are mainly concerned with relationships between bodily processes and behavior. They may, for example, conduct research on how the brain regulates various motivations, such as hunger and thirst. They are also interested in the effect of brain on perceptual learning and in the study of chemical processes underlying vision.