The relation between experimental psychology and second language acquisition research has
gone through at least two major swings of the pendulum. During the heyday of behaviorism, the
pendulum swung strongly toward psychology. The behaviorist psychologists advised us to think
of language learning as nothing more than habit formation (Mowrer, 1960), and second language
learning materials reflected an emphasis on repetition, drill, rewards, practice, and conditioning.
During the early years of the cognitive revolution, Chomsky (1959) argued that viewing language
as a conditioned response (Skinner, 1957) ignores the complexities of both language structure
and cognition. Persuaded by these arguments, second language researchers turned away from
behaviorist psychology and sought the explanation for language acquisition in universals of
language structure (Dulay & Burt, 1974).