Some divisions of Psychology are applied fields, while others are more experimental in nature. The various applied fields include clinical, counselling, industrial, engineering, or Personnel, consumer and environmental. The most important of these specialities, clinical psychology, is concerned with the diagnosis and treatment of mental disorders' The broad field known as experimental psychology includes specialisations in child educational, social, developmental, psychological, and comparative psychology. Of these, child psychology applies psychologicalih.ory and research methods to children, educational Psychology is concerned with learning processes and problems associated with the teaching of students; social psychology is concerned with group dynamics and other aspects of human behaviour in its social and cultural setting, and comparative Psychology deals with- behaviour as it differs from one species of animal to another. The issues studied by psychologists cover a wide spectrum, comprising learning, cognition, intelligence, motivation, emotion, perception, Personality ,mental disorders, and the study of the extent to which individual differences are inherited or are shaped environmentally, known as behaviour genetics. The present book in two volumes, consists of twenty-four chapters covering all major aspects of experimental psychology.