The importance of history in defining who we are cannot be overstated.

getting a history of the field helps to make sense of where we are and how we got here.

Precursors to American psychology can be found in philosophy and physiology. Philosophers such as John Locke (1632–1704) and Thomas Reid (1710–1796) promoted empiricism, the idea that all knowledge comes from experience.

Philosophical questions about the nature of mind and knowledge were matched in the 19th century by physiological investigations of the sensory systems of the human observer.

An important implication of Helmholtz’s work was that there is a psychological reality and a physical reality and that the two are not identical.

The question of the relationship between the mental (experiences of the senses) and the material (external reality) was investigated by a number of German researchers including Ernst Weber and Gustav Fechner.

The work of Wundt and his students demonstrated that the mind could be measured and the nature of consciousness could be revealed through scientific means.

Experimental psychology spread rather rapidly throughout North America. By 1900, there were more than 40 laboratories in the United States and Canada (Benjamin, 2000). Psychology in America also organized early with the establishment of the American Psychological Association (APA) in 1892.