The learning theory of psychologist Edward L. Thorndike (1874-1949) represents the original S-R framework of behavioral psychology: Learning is the result of associations forming between stimuli (S) and responses (R). Such associations or "habits" become strengthened or weakened by the nature and frequency of the S-R pairings. The paradigm for S-R theory was trial and error learning in which certain responses come to dominate others due to rewards. The hallmark of connectionism (like all behavioral theory) is that learning can be adequately explained without referring to any unobservable internal states.

Principles:

1. Learning requires both practice and rewards (laws of effect/exercise)
2. A series of S-R connections can be chained together if they belong to the same action sequence (law of readiness).
3. Transfer of learning occurs because of previously encountered situations.
4. Intelligence is a function of the number of connections learned.