and founder of behaviourism. His first major work, Behavior: an Introduction to Comparative Psychology (1914), established the principles of scientific behaviourism, rejecting any reliance on introspection, consciousness, or intentionality in favour of observation and experiment in laboratory settings. His best-known textbook was Psychology from the Standpoint of a Behaviorist (1919). Watson spent the years after 1920 in advertising, perhaps appropriately as he became notorious for an antihumanist, mechanical, and emotionally arid approach to infant nurture.