Psychology is the scientific study of the mind and behavior. It includes many sub-fields of study such areas as human development, sports, health, clinical, social behavior and cognitive processes. Psychology investigates an enormous range of phenomena: learning and memory, sensation and perception, motivation and emotion, thinking and language, personality and social behavior, intelligence, child development, mental illness, and much more
The word, ‘Psychology’ is derived from two Greek words, ‘Psyche’ and ‘Logos’. Psyche means ‘soul’ and ‘Logos’ means ‘science’. Thus psychology was first defined as the ‘science of soul”.
According to earlier psychologists, the function of psychology was to study the nature, origin and destiny of the human soul. But soul is something metaphysical. It cannot be seen, observed and touched and we cannot make scientific experiments on soul.
In the 18th century, psychology was understood as the ‘Science of Mind’. William James defined psychology as the science of mental processes. But the word, ‘mind ‘is also quite ambiguous as there was confusion regarding the nature and functions of mind.
Modern psychologists defined psychology as the “Science of Consciousness”. James Sully defined psychology as the “Science of the Inner World”. Wilhelm Wundt defined psychology as the science which studies the “internal experiences’. But there are three levels of consciousness – conscious, subconscious and the unconscious and so this
definition also was not accepted by some.
Behavior generally means overt activities which can be observed and measured scientifically. But one’s behavior is always influenced by his experiences. So when we study one’s behavior we must also study his experiences.
Psychology should, therefore, be defined as a “science of behavior and experiences on human beings” (B.F. Skinner)
According to Crow and Crow, “Psychology is the study of human behavior and human relationship’”.