The word Psychology is made of two ancient Greek words – psyche meaning soul and logos meaning word. Thus, Psychology pertains to the study of mind, thought, and behaviour. Although the subject mainly studies the human behavior but the animal behavior is also studied either as a separate branch of psychology (animal cognition) or it is studied in order to gain insight into human behavior and psychology by making a comparison between the two (comparative psychology). Wilhelm Wundt was the first person to call himself a “psychologist”, and he opened the first psychological laboratory in 1879 and it is only recently that Psychology has developed as a separate discipline and science. 

It must be observed that Psychology does not study brain or nervous system as such but rather it is studied in terms of phenomenological or information processing theories of mind. However, in the recent past psychology has included a deeper understanding of brain function both in psychological theory and practice, especially in the fields of cognitive neuroscience, neuropsychology and artificial intelligence. 

The study of Psychology is conducted in a scientific as well as non-scientific manner. Psychology has an eclectic approach and it draws on scientific knowledge from diverse fields of knowledge in order to explain and understand behaviour. The mainstream psychology largely draws up on positivism and it derives data from quantitative studies and uses scientific methods to test hypotheses in an experimental setting. Yet all psychological research methods don’t adhere to the classical scientific approach and method. The proponents of humanistic psychology completely reject a scientific approach while the mainstream psychology is biased towards the scientific methodology and it is dominated by cognitivism in its understanding of thought and behaviour. 

Psychology has a different approach in comparison to anthropology, sociology, political science and economics in order to study behavior. While Psychology studies behaviour of individuals (alone or in groups), the other sciences confine themselves to the behaviour of groups or aggregates themselves.