What is the field of psychology? It’s a vast subject that is only briefly touched on in this series of posts. It can be seen as the bridge between philosophy and physiology. Physiology is the branch of biology that deals with the normal functions of living organisms and their parts. Philosophy deals with thoughts and ideas, and psychology deals with how we come to have these thoughts and what they tell us about how our brains work.

As the DK book called The Psychology Book Big Ideas Simply Explained says, all sciences developed from philosophy by applying scientific methods to philosophical questions. Only in the 19th century did psychology become established as a scientific discipline in its own right. The world’s first laboratory of experimental psychology was established by Wilhelm Wundt at the University of Leipzig in 1879. By the way, the oldest monument to Johann Sebastian Bach is in Leipzig Germany. All the branches of psychology grew in the 20th century.

In the early days of the development of the discipline of psychology, there were two different approaches. In the United States, the roots lay in philosophy and was therefore theoretical in nature. In Europe, psychology was rooted in the sciences, so the emphasis was on mental processes like memory and perception.

Thoughts are very subjective but actions are more objective. It’s much easier to simply observe an animal or person’s actions than their thoughts that proceed it. Ivan Pavlov’s experiments in the 1890’s were key to the advancement of psychology . He proved that animals could be conditioned to produce a response, an idea that developed into a new movement called behaviorism. Behavior is shaped by interaction with the environment. This is a “stimulus-response” theory. This spawned new learning theories.

Psychology moved through several movements, namely philosophy, behaviorism, psychotherapy and the study of cognitive, social and developmental psychology, and finally to the psychology of difference.