Fred Keller was born. A pioneering experimental psychologist and radical behaviorist who taught at Columbia University for 26 years, Keller is renowned for developing the Personalized System of Instruction (PSI); an innovative educational method rooted in Skinnerian behavior theory.

A skilled orator and prolific writer, 'Principles of Psychology: A Systematic Text in the Science of Behavior' first published in 1950 ranks among Keller's most influential publications.

In 1976, Keller received the American Psychological Association (APA) Distinguished Scientific Award for the Applications of Psychology.