For more on Behaviourism see secs. , and .
Ivan Pavlov (1849-1936) Russian physiologist - numerous studies on classical conditioning. Using dogs as subjects, Pavlov paired a conditioned stimulus (food) that normally elicited a conditioned response (salivation) with an unconditioned stimulus (bell ringing). Eventually, the unconditioned stimulus became associated with the conditioned response. Pavlov also showed that conditioned responses could not be learned by dogs after removal of the cerebral cortex
John B. Watson (1878-1958) founded the behaviourist movement in the USA.
The proper subject for psychology is not the operation of the mind but the examination of objective, observable behaviours. There are no mental causes: the only causal relations are between stimuli and responses.
Operant conditioning - B.F. Skinner (1904-1990)
Of the behaviourists, Edward Tolman (1886-1959) felt that instead of conceptualising the brain as a telephone switchboard which connected stimuli directly to response it would be more profitable to think of ``a map room'' where stimuli were sorted out and arranged before the response occurred (mediation theory).
Tolman proposed that rats navigate by constructing ``cognitive maps.'' He also demonstrated learning without reward or punishment ``latent learning'', learning of associations that is not directly evident in changes in behaviour (?) and he posited a role for expectations, purpose, meaning and other ``intervening variables.''
Tolman's primary rival was neobehaviourist Clark Hull (1884-1952) (Principles of Behaviour, 1943). Hull's mathematico-deductive theory of instrumental conditioning:
Response strength (reaction time) a function of drive (i.e. hours of food deprivation) and habit strength (fn of no. of reinforcements).
In Skinner's operant conditioning paradigm there were no intervening variables and in fact no formal theory.