Theory of learning investigated and developed by the Russian physiologist J.P.Pavlov (1849–1936). A spontaneous (conditioned) reaction, triggered by a particular stimulus can in turn be triggered by another stimulus if this other stimulus is repeatedly combined with the original stimulus; after training, the reaction will occur in response to the second stimulus even if it is given without the original stimulus (stimulus-response). This form of conditioning was used, influenced by the behaviorist school (behaviorism; see Skinner 1957), to explain language acquisition. Thus, meanings are purportedly learned by pointing to (unconditioned stimulus) and naming (second stimulus) the given object until such time as merely uttering the word produces reference to the object.
Producing such reactions can be accelerated and stabilized or intensified by an appropriate reward. Such cases are known as ‘instrumental’ or ‘operant’ conditioning (in contrast to the ‘classical’ conditioning by Pavlov 1929).
