John Watson

John Broadus Watson (January 9, 1878 – September 25, 1958) was an American psychologist who established the psychological school of behaviorism, after doing research on animal behavior. He also conducted the controversial "Little Albert" experiment. Later he went on from psychology to become a popular author on child-rearing, and an acclaimed contributor to the advertising industry.

http://en.wikipedia.org/wiki/John_B._Watson

Ivan Pavlov

Ivan Petrovich Pavlov (Russian: Иван Петрович Павлов, September 14, 1849 – February 27, 1936) was a Russian, and later Soviet, physiologist, psychologist, and physician. He was awarded the Nobel Prize in Physiology or Medicine in 1904 for research pertaining to the digestive system. Pavlov is widely known for first describing the phenomenon of classical conditioning.

http://en.wikipedia.org/wiki/Ivan_Pavlov