History of psychology.

The beginnings of psychology can be traced back to when René Descartes wrote about the duality of the human being, establishing the difference between the body and the soul.

The first time someone wrote a book trying to explain how the human mind works was in 1754 when Hume wrote about how impressions influence our thinking. However, this was more philosophy than psychology.

In 1873, Wilhelm Wundt published "Principles of Physiological Psychology." This was the first book to discuss psychology.

Sigmund Freud was the first psychologist to begin treating patients by exploring the unconscious mind. This was a revolutionary advance in psychology.

Wertheimer, Koffka, Köhler, and the Gestalt psychologists discussed sensation and perception.

Between 1849 and 1936, Ivan Pavlov conducted experiments on animal behavior using a system of rewards and punishments. He argued that the human mind could be taught to behave in a certain way.

Between 1908 and 1970, Abraham Maslow proposed a hierarchy of human needs.