The predominant school of thought in learning theory during the first fifty years of the 20th century was behaviorism.
Behaviorism flourished in the 1950's with the birth of Skinner's programmed instruction movement and its application to instruction. Behaviorism thought of learning as a stimulus, response, and reinforcement process (S-R-R) which is mainly a reactive behavior. Skinner's work on negative and positive reinforcement, and schedules of reinforcement, emphasized the phenomena that in order for learning to take place, the behavior (response of a learner) must be modified or shaped (operant conditioning) by reinforcing it appropriately.
Behaviorism has its roots in Thorndike's Laws of Effect, readiness and exercise (practice), and Pavlov's Classical Conditioning theory.
The implications of the behaviorist approach on instructional technology led to the design of piecemeal instruction with immediate feedback and reinforcement, drill and practice procedures, and self-paced programmed instruction that branched the learner to repeat or revisit certain pieces or modules of the instruction based on the correctness of the learner's response (behavior). Behavioral objectives connected outcomes and instruction.
The Rise and Eclipse of Behaviorism
"At the turn of the new century, behavior theory, while still viable, no longer holds the dominance it once did in theoretical psychology." This is part of the conclusion of an article called "Behaviorism: the Rise and Fall of a Discipline" at the APA Monitor Online s site of the American Psychological Association. The article gives a quick overview of the history of a school of thought that still provides most of the structure of training programs. (Volume 30, Number 11 December 1999)