Adult Learning Timeline By clarke0811 1833 Alexander Kapp - the first known user of the andragogy concept link Period: 1920 to 1929 ean Piaget develops cognitive theory link 1921 John B. Watson studies an 11 month old child, concluding that classical conditioning could cause phobias in humans. link 1926 Eduard C. Lindeman - publishes The Meaning of Adult Education: link text 1937 B.F. Skinner introduces the Operant Conditioning Model link 1960 Jerome Bruner's The Process of Education has a great influence on education in the U.S. link 1962 Fred Keller - develops The Keller Plan link 1972 John D. Ingalls and Joseph M. Marceri publish A Trainer's Guide to Andragogy link 1978 Lev Vygotsky's work is published by Harvard University Press link 1981 Jack Mezirow proposes "Charter for Andragogy" link