Learning Theory

Theory about how people learn and modify pre-existing thoughts and behavior.

Psychologists have suggested a variety of theories to explain the process of learning. During the first half of the 20th century, American psychologists approached the concept of learning primarily in terms of behaviorist principles that focused on the automatic formation of associations between stimuli and responses. One form of associative learning— classical conditioning—is based on the pairing of two stimuli. Through an association with an unconditioned stimulus (such as meat offered to a dog), a conditioned stimulus (such as a bell) eventually elicits a conditioned response (salivation), even when the unconditioned stimulus is absent. Principles of classical conditioning include the extinction of the response if the conditioned and unconditioned stimuli cease to be paired, and the generalization of the response to stimuli that are similar but not identical to the original ones. In operant conditioning, a response is learned because it leads to a particular consequence (reinforcement), and it is strengthened each time it is reinforced. Positive reinforcement strengthens a response if it is presented afterwards, while negative reinforcement strengthens it by being withheld. Once a response has been learned, it may be sustained by partial reinforcement, which is provided only after selective responses.

In contrast to theories of classical and operant conditioning, which describe learning in terms of observable behavior, intervening variable theories introduce such elements as memory, motivation, and cognition. Edward Tolman demonstrated in the 1920s that learning can involve knowledge without observable performance. The performance of rats who negotiated the same maze on consecutive days with no reward improved drastically after the introduction of a goal box with food, leading to the conclusion that they had developed "cognitive maps" of the maze earlier, even in the absence of a reward, although this "latent learning" had not been reflected in their observable behavior. Even earlier, Wolfgang Köhler, a founder of the Gestalt school of psychology, had argued for the place of cognition in learning. Based on experiments conducted on the island of Tenerife during World War I, Köhler concluded that insight played a role in problem-solving by chimpanzees. Rather than simply stumbling on solutions through trial and error, the animals he observed seemed to demonstrate a holistic understanding of problems, such as getting hold of fruit that was placed out of reach, by arriving at solutions in a sudden moment of revelation or insight.

The drive-reduction theory of Clark L. Hull and Kenneth W. Spence, which became influential in the 1930s, introduced motivation as an intervening variable in the form of homeostasis, the tendency to maintain equilibrium by adjusting physiological responses. An imbalance creates needs, which in turn create drives. Actions can be seen as attempts to reduce these drives by meeting the associated needs. According to drive-reduction theory, the association of stimulus and response in classical and operant conditioning only results in learning if accompanied by drive reduction.

In recent decades, cognitive theories such as those of social learning theorist Albert Bandura have been influential. Bandura is particularly known for his work on observational learning, also referred to as modeling or imitation. It is common knowledge that children learn by watching their parents, other adults, and their peers. According to Bandura, the extent to which children and adults learn behaviors through imitation is influenced not only by the observed activity itself but also by its consequences. Behavior that is rewarded is more readily imitated than behavior that is punished. Bandura coined the term "vicarious conditioning" for learning based on the observed consequences of others' actions, listing the following requirements for this type of learning: attention to the behavior; retention of what is seen; ability to reproduce the behavior; and motivation. Cognitive approaches such as Bandura's have led to an enhanced understanding of how conditioning works, while conditioning principles have helped researchers better understand certain facets of cognition.

Computers play an important role in current research on learning, both in the areas of computer-assisted learning and in the attempt to further understand the neurological processes involved in learning through the development of computer-based neural networks that can simulate various forms of learning.