Psychology is the study of the mind and behavior. The history of psychology began in the late 19th century with Wilhelm Wundt opening the first experimental laboratory in psychology at the University of Leipzig in 1879. Key figures who contributed to the development of psychology include Sigmund Freud who developed psychoanalysis in 1896, Ivan Pavlov who developed classical conditioning in 1921, and B.F. Skinner who proposed operant conditioning.