Definition and Introduction to Psychology

Terminologies Used in Psychology

Psychology is both an academic and applied discipline involving the scientific study of mental processes and behavior. In this definition, there are three key words; scientific study (science), mental processes and behavior.

Science: It deals with a group of related facts and principles of a particular subject. It emphasizes the search for truth. Not only it collects related facts by the use of objective methods, but it also develops a theory to explain those facts. It arrives at some principles and laws. It can predict behaviour, given a certain set of circumstances. In fact, objectivity, reliability, validity and predictability are characteristics of science.

Psychology as a science deals systematically with human as well as animal behaviour, along with their motives, feelings, emotions, thoughts and actions. It discovers and explains the underlying laws and principles of behaviour. Like in science, psychologists do experiments and make observations which others can repeat and verify. Like a science again, it can predict the behaviour which will occur, if given a certain set of circumstances, to some extent.

Mental Processes: These include all private/ individual psychological activities which can't be directly observed by others but can be seen in activities; what a person does- his or her behaviour- is the avenue through which internal mental events can be studied.

Behaviour: It includes all observable activities (motor activities: walking, speaking etc., cognitive activities: perceiving, remembering, thinking, reasoning etc., emotional activities: feeling happy, angry, sad etc.). It includes all reactions and responses to the environmental stimuli.

Evolution of the Meaning of Psychology

In 1590, Rudolf Geockle used the word psychology for the first time (Anthikad, 2004). It is derived from two Greek words "psyche" and "logos". "Psyche" meaning "soul" and "logos" meaning "discourse". Psychology was thus literally the study of the soul. However, the of the word psychology has undergone many changes from time to time. Four distinct phases can be seen in the evolution of the concept of psychology as it stands today. 

• Phase 1: Psychology as the science of soul:
  Ancient Greek philosophers like Aristotle (384-322BC) and Plato (427-347BC) interpreted psychology as "the study of soul". According to them, the function of psychology was to study the nature, origin and destiny of the human soul. But soul is something metaphysical. The nature of soul could not be satisfactorily explained. Hence, the definition of psychology as the science of soul was given up.

• Phase 2: Psychology as the science of mind:
  Failure to define soul properly led some ancient Greek philosophers to define psychology as "the study of mind" and they considered it as a branch of mental philosophy. Mind, according to them, was the subject matter of psychology. But, the nature of mind was interpreted in different ways by different psychologists and this led to confusion and hence this definition was also rejected.

• Phase 3: Psychology as the science of consciousness:
  In the 19th century, psychologists like William James (1842 - 1910) and William Wundt (1832 - 1920) concluded to define psychology as "the science of consciousness". They argued that the description and explanation of states of consciousness was the task of psychology. This definition was also rejected on the ground that consciousness constituted only a negligible portion of total personality and it was not taking into consideration of subconscious and unconscious states of the mind. 

• Phase 4: Psychology as the science of behaviour:
  In the beginning of the 20th century, a scientific revolution occurred in the field of psychological thought and as a result psychology was emerged as "the science of behaviour". In 1905, McDougall defined psychology as the "positive science of conduct of living creature". In the same period, Pillsburry (1911) defined psychology as "the science of human behavior". Later, J. B. Watson (1878-1958), the father of the behaviourist school, proposed to elaborate the meaning of the term behaviour including in it both human and animal behaviour and consequently he defined psychology as "the science of behavior", taking into account the human as well as animal behaviour.