This material is provided by Robert Kentridge,
University of Durham, England.
The position that human behaviour could be explained entirely terms of reflexes, stimulus-response associations, and the effects of reinforcers upon them entirely excluding 'mental' terms like desires, goals and so on was taken up by John Broadhus Watson in his 1914 book 'Behavior: An Introduction to Comparative Psychology.'. Watson had also been involved in the introduction of the most favoured subject in comparative psychology - the laboratory rat.
One of his early jobs which he used to fund his Ph.D. was as a caretaker, one of whose duties was to look after laboratory rats used in studies intended to mimic 'real-life' learning tasks such as navigating complex mazes (a scale-model of the Hampton-Court maze!). Watson became adept at taming rats and found he could train rats to open a puzzle-box like Thorndike's for a small food-reward. He also studied maze- learning but simplified the task dramatically. One type of maze is simply a long straight alley with food at the end. Watson found that once the animal was well trained at running this 'maze' it did so almost automatically. Once started by the stimulus of the maze its behaviour becomes a series of associations between movements (or their kinaesthetic consequences) rather than stimuli in the outside world. This is made plain by shortening the alleyway - the well-trained rats now run straight into the end wall. This was known as the kerplunk experiment.
The development of well-controlled behavioural techniques by Watson also allowed him to explore animals sensory abilities, for example their abilities to discriminate between similar stimuli, experimentally. Watson's theoretical position was even more extreme than Thorndike's - he would have no place for mentalistic concepts like pleasure or distress in his explanations of behaviour. He essentially rejected the law of effect, denying that pleasure or discomfort caused stimulus-response associations to be learned. For Watson, all that was important was the frequency of occurrence of stimulus-response pairings. Reinforcers might cause some responses to occur more often in the presence of particular stimuli, but they did not act directly to cause their learning. Watson could therefore reject the notion that some mental traces of stimuli and responses needed to be retained in an animals mind until a reinforcer caused an association between them to be strengthened, which is a rather mentalistic consequence of the law of effect.
Watson became an extremely influential force in American Psychology, publishing his second book 'Psychology from the Standpoint of a Behaviorist' in 1919. His rejection of mentalism was total. He felt that thought was explicable as subvocalisation and that speech was simply another behaviour which might be learned by the law-of effect. In Psychology from the Standpoint of a Behaviorist' he addresses a number of practical human problems such as education, the development of emotional reaction and the effects of factors like alcohol or drugs on human performance. He even suggests that thought processes might be investigated by monitoring movements in the larynx.
Watson believed that mental illness was the result of 'habit distortion' which might be caused by fortuitous learning of inappropriate associations which then go on to influence a person's behaviour so that it become ever more abnormal. Watson tested part of this hypothesis on a baby in the hospital in which he worked. The baby, 'little Albert', apparently showed no particular fears or phobias about anything apart from sudden loud sounds. For example, when Watson placed a tame white rat in little Albert's lap the child happily played with the animal.
On a subsequent occasion Watson placed the rat in Albert's lap and his assistant made a loud noise by striking a large steel bar directly behind Albert's head. One week later Albert was subjected to the same experience. After this, when Albert was showed the rat be began to fret, appearing anxious. Similar reactions were produced by other furry objects (a fur coat). Watson was keen to use this as evidence for the behavioural basis of phobias, however, apparently Albert's reactions to the rate were quite mild. Nevertheless, one of the most widespread applications of conditioning has been in the treatment of phobias and other behaviour problems, and the case of Little Albert is often cited as the first experiment in this field.
The Fall and Rise of J.B.Watson
Shortly after his experiment on Little Albert Watson became romantically involved with one of his research assistant's - Rosalie Rayner. At the time such behaviour was not tolerated in American academia and Watson was eventually forced to retire from research.
He soon, however, found gainful employment with the J. Walter Thompson advertising agency where, using techniques from his behavioural psychology, he showed that people's preferences between rival products were not based on their sensory qualities but on their associations. He went on to develop the selling of products like Maxwell House Coffee, Pond's Cold Cream, Johnson's Baby Powder and Odorono (one of the first deodorants). By 1924 he was on of the four vice-presidents of this very successful agency.