Thorndikes Connectionism

Edward L. Thorndike (1911/1965) is credited with founding the study of instrumental learning and placing comparative psychology on an experimental foundation. He was specifically interested in the question of how performance improved through trial and error, and he performed numerous experiments involving problem solving in cats and other animals.

Basic Mechanisms of Behavioral Change: Stamping In and Stamping Out in the typical experiment, a cat was confined inside a puzzle box equipped with various mechanisms that could be manipulated to gain escape. A piece of fish was placed just outside of the cage as an added incentive. Thorndike measured the amount of time it took for each cat to find a way out, for example, by pulling on a loop of string or stepping on a platform arranged to release the door. Typically, cats engaged in a great deal of anxious searching behavior until they happened upon the correct solution by chance. Over the course of succeeding trials, the cats gradually became more skilled at escape. Thorndike observed that cats did not learn through insight or discovery but struggled through a process of trial and error with successful behaviors being stamped in, whereas frustrating, unsuccessful behaviors were stamped out. He concluded that a response was directly connected or bonded to the associated stimulus complex through a process of stamping in. According to Thorndike, all "learning is connecting." The animal's trial-and-error learning is dependent neither on deliberate reasoning nor on the exercise of some specialized instinct but depends entirely on the selective stamping in or stamping out of relevant S-R connections.

Thorndike's Basic Laws

Thorndike sums up his experimental findings in three basic laws of learning:

1. The law of effect states that an S-R connection (or bond) is strengthened or weakened depending on the hedonic quality of consequences following it. A response followed by a reward or "satisfier" strengthens the S-R bond and is stamped in. A response followed by a punisher or "annoyer" is weakened and is stamped out.

2. The of law of exercise states that a response is strengthened through use and weakened through disuse.

3. The law of readiness is couched in a pe culiar language of conduction units. Hilgard and Bower (1975) suggest that what Thorndike means by such units is an objective action tendency or preparation for action. When an animal is motivationally prepared to act, then the performance of the action is satisfying. When an animal is ready to act but prevented from doing so, the animal is annoyed, i.e., mildly punished or frustrated. Annoyance is also experienced (expressed as resistance) when an animal is motivationally unprepared to act but compelled to do so anyway. Readiness to act is affected by an animal's mental set or attitude (i.e., personal motivations determining what will annoy or satisfy it at any given moment). The law of readiness anticipates in several details Premack's theory of reinforcer reversibility (Premack, 1962). What under one set of motivational conditions is reinforcing may be punitive under another. For example, a satiated dog may find the opportunity to go for a walk more satisfying than the chance to eat more food. Additional eating for a satiated dog is punitive, i.e., annoying. On the other hand, a well-exercised dog would more likely choose to eat than undergo additional exercise. Whether a particular activity is annoying or satisfying is relative to the animal's varying motivational state.

Thorndike's law of effect underwent significant modification in his later writings. As the result of studies involving the use of mild punishment such as the word wrong or brief isolation, he generalized (wrongly) that punishment did not weaken instrumental behavior as he had previously postulated in the second half of the law of effect (see Chapter 9). Although he still recognized the power of punishment to disrupt behavior, he no longer believed that it was sufficient to alter learned connections to the same extent that rewards do. He also revised the law of exercise. He now argued that learning was not substantially influenced by the mere effort of practice and repetition, although such practice may benefit the performance of an already learned connection. For practice to be effective (i.e., promote additional learning), the repeated behavior must be associated with reinforcement—rote practice will not alter learned connections by itself.

Thorndike's emphasis on reward over punishment was an important contribution in the development of modern educational philosophy. Although subsequently proven wrong by a variety of studies, the rejection of punishment and the endorsement of more positive methods for behavioral control had a widespread and beneficial effect on animal training, child-rearing practices, and educational programs.

Dog Training 101

Dog Training 101

If you own a dog, you will have to do more than just feed him and give him toys to play with. Just about every dog, no matter what breed, will have some bad habits and behaviors that you will need to break.

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