William James (1842 – 1910)
William James is considered by many to be the father of American psychology, representing the transition of influence in the field from Europe to the United States. Many of his influential ideas were first presented in his landmark publication, The Principles of Psychology. From these ideas, the school of functionalism grew.
James helped to fold the evolutionary theories of Charles Darwin and others into the prevailing psychological trends. He also expanded the scope of psychology by studying all aspects of human behavior. James introduced several influential concepts, including the stream of consciousness, the impact of habits and instincts, aspects of the self, the James-Lange theory of emotion, and the ideo-motor theory of behavior.