Behaviourist theory was developed from the 1920s onwards in the work of the work of psychologists such as Watson and Skinner. It argued that all behaviour could be explained by observable factors - it was unnecessary to refer to mental processes.
Behaviourism and Learning
Behaviourists explained learning as a matter of stimulus - response - reinforcement. An action performed (the stimulus), possibly by chance, would create a result (the response). If this result was positive, the behaviour would be reinforced - the learner would want to repeat it. If it was negative, then they would not. Skinner exemplified this with experiments with rats : a hungry rat in a box would, by chance as it moved around, knock a lever at the side, causing a food pellet to fall out. Soon the rats would learn to press the lever intentionally. If, on the other hand, touching the lever produced a negative consequence, such as an electric shock, they would learn to stay away from the lever.
Behaviourism and First Language Acquisition
Skinner argued that children acquire language in the same way. Correct utterances are positively reinforced, while incorrect utterances are not. So for example, if the child says ‘teddy’ and the mother says "Here's teddy" and passes the bear to the child, the verbal behaviour is reinforced - the child learns that it works.
Behaviourism and Second Language Learning
Behaviourist theory was applied to second language learning in the 1930s, when the Audiolingual Method was developed. A typical audiolingual technique was the use of drills. Repetition drills were based on a model sentence (the stimulus) - eg I go to the supermarket every Saturday - which the learners would first repeat (the response). The teacher would then evaluate the response (the reinforcement) positively or negatively. If the drill was continued as eg a substitution drill, the teacher would then provide a stimulus - another word such as library - and the student would respond by substituting it in the model sentence. The teacher's positive or negative evaluation would again provide the reinforcement. For example :
T : OK, everyone - listen and repeat : I went to the supermarket on Saturday (stimulus)
Ss: I went to the supermarket on Saturday (response)
T : Lovely (positive reinforcement) - Jean, again : I went to the supermarket on Saturday. (stimulus)
J : I went to the supermarket on Saturday. (response)
T Good.. ... (positive reinforcement)
T : OK - Ayeesha - library. (stimulus)
A : I went to the library /laɪbə'reriː/ on Saturday. (response)
T : Mmm.... (negative reinforcement) Listen to the pronunciation /'laɪbrəriː/(stimulus)
A : /'laɪbrəriː/ (response)
T : Much better (positive reinforcement)