What is Psychology? | Definition of Psychology

The word psychology is derived from the Greek words ‘Psyche‘ and ‘logos.’ The term ‘psyche‘ means soul, whereas the word ‘logos‘ means study. So, the literal meaning of psychology was the study of the soul. As the soul has no physical existence and possesses mystical characteristics, this definition of psychology “study of the soul” was rejected. 

As psychology is a highly interdisciplinary discipline, it is hard to find the exact definition, but most of the professionals agree on this definition,

“Psychology is the scientific study of mental/cognitive processes and behavior.”

The phrases scientific studybehavior, and mental processes must be understood to mean many things.

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Scientific Study

Psychologists use the scientific method to find answers to the various questions related to mental processes and behavior rather than intuition and speculation.

Scientific study/method is a technique for investigating phenomena that are based on observation and measuring events. In psychology, knowledge is gathered by the careful organization of observed facts. Measurement is an inevitable part of scientific study. While everyone is familiar with the measurement of physical objects like weight, length, and temperature, etc., one might wonder how the concept of measurement implies in psychology.

Unlike physical sciences such as physics and chemistry, many things in psychology can not be measured directly. For example, Different psychological attributes like happiness, love, etc. can not be measured using physical scales. How do you measure happiness? As happiness is a value judgment, different people have a different definition of happiness. These things that are difficult to measure are measured using various scales. It is also important to note that not everything that psychologists study is difficult to measure like happiness.

Mental Process

The term mental process or cognitive process is used to indicate the things that the brain does continuously. These include sensation, perception, attention, learning, memory, thinking, reasoning, problem-solving, and so on. Mental processes are assumed to involve the acquisition, storage, interpretation, manipulation, transformation, and use of knowledge. In short, mental processes includes all the workings of the human mind.


Behavior is anything that a person or an organism does. The study of behavior is really important as various internal processes occurring in the brain are manifested through what people do.

As wonderfully put forward by Morgan et al., “behavior is the avenue through which mental processes are studied.” There are two types of behavior; overt behavior and covert behavior. The readily observable behavior called overt behavior, and the behavior which is not observable is called covert behavior. Gestes, postures, and actions such as running dancing, etc. are examples of overt behavior, while the covert behavior includes deception, lying, thinking, and so on.

More about Psychology

Psychology also helps to solve many real-life problems that you encounter in your daily life, but you can’t relate everything that you studied in your everyday life experience. Psychology tries to understand almost all aspects of human behavior, including everything we think, feel, or experience. To achieve this goal, many pioneers of this highly interdisciplinary field have embraced a variety of perspectives.

These perspectives offer different views on mental processes and behavior, each having their strengths and weakness. They also emphasize on various factors.

The prospectives of psychology are biological/neuroscience perspective (focusing on the biological characters such as genes and physiology), behavioral perspective (focusing on the observable/overt behavior), cognitive perspective (focusing on the various cognitive process like memory, thinking, problem-solving, etc.), humanistic perspective (focusing on human virtues), psychodynamic perspective (focusing on the unconscious forces), evolutionary perspective (focusing on the inherent tendencies shaped by evolution), developmental perspective (focusing on changes in behavior and cognitive processes over the lifespan), socio-cultural perspective (focusing on various social and cultural factors), etc.