Conditioning is a broad term to describe techniques used by psychologists to study the process of learning.
Psychology has often been defined as the study of behavior. In behavioral psychology, conditioning is the process that states a response (what is known as a reaction) to an object or event (a stimulus or reward) by a person or animal in a given environment, which can be modified (or conditioned) by learning. The theories based on conditioning are generally called stimulus-response (S-R) theories. Thus, behaviorists, those who study behaviorism, believe that behaviors are the result of conditioning.
Beginning in the early twentieth century, American, British, and Russian physiologists, and then later psychologists, began to develop definitions, observations, and procedures about conditioning. As such, physiologists and psychologists have developed a diverse array of methods for studying both human and nonhuman animal activity.
Two of the most commonly used techniques are classical conditioning and operant conditioning. They have been used to study the process of learning, one of the key areas of interest to psychologists in the nineteenth-century early days of psychology. Psychologists also attach considerable significance to conditioning because it has been effective in changing human and nonhuman animal behavior in predictable and desirable ways.
The Russian physiologist Ivan P. Pavlov (1849– 1936) developed the principles of classical conditioning. In his Nobel Prize–winning research on the digestive processes, he placed meat powder in the mouths of his research animals and recorded their levels of salivation. At one point, he noticed that some of his research animals began to salivate in the absence of food. He reasoned that the presence of the animal caretakers led the animals to anticipate the meat powder, so they began to salivate even without the food.
When classical conditioning occurs, an animal or person initially responds to a naturally occurring stimulus with a natural response (e.g., the food leads to salivation). Then the food is systematically paired with a previously neutral stimulus (e.g., a bell or metronome), one that does not lead to any particular response. With repeated pairings, the natural response occurs when the neutral stimulus appears. The original salivation when food is introduced to the animal (such as a dog) is called the unconditioned response (UR) whereas the food itself is the unconditioned stimulus (US). However, the bell, for example, eventually becomes the conditioned stimulus (CS) and the salivation by the animal upon hearing the bell is the conditioned response (CR).
Pavlovian (i.e., classical) conditioning influenced psychologists greatly, even though Pavlov himself was skeptical of the work psychologists performed. In the United States, John B. Watson (1878–1958), the first widely known behaviorist, used the principles of classical conditioning in his research. For example, in a widely cited study, Watson tried to develop a classically conditioned phobia in an infant.
Although classical conditioning became the dominant Russian model for the study of behaviorism, another form of conditioning took hold in the United States. This version, which became known as operant or instrumental conditioning, initially developed from the ideas of the psychologist Edward L. Thorndike (1874– 1949). Thorndike began his psychological research by studying learning in chickens then in cats. Based on the problem solving of these animals, he developed the law of effect, which in simple form states that a behavior that has a positive outcome is likely to be repeated.
Similarly, Thorndike's law of exercise states that the more a response occurs in a given situation, the more strongly it is linked with that situation, and the more likely it is to be repeated in the future. Thorndike's behavioral theories of stimulus (S), organism/ individual (O), and response (R), often abbreviated as S-O-R theories, helped to explain social interactions between individuals and groups of individuals.
Operant conditioning was popularized by the American psychologist Burrhus Frederic Skinner (1904–1990), who is more commonly known as B. F. Skinner. His research and writings influenced not only psychologists but also the public, in general. Operant conditioning differs from classical conditioning in that, whereas classical conditioning relies on an organism's response to some stimulus in the environment, operant conditioning relies on the organism's initiating an action that is followed by some consequence.
For example, when hungry individuals put money into a vending machine, they are rewarded with some product. In psychologists’ terms, the behavior is reinforced; in everyday language, the individuals are satisfied with the outcome. As a result, the next time they are hungry, they are likely to repeat the behavior of putting money into the machine. However, if the machine malfunctions and the individuals get no food, then they are less likely to repeat the behavior in the future. This outcome is called punishment.
Any time a behavior leads to a positive outcome that is likely to be repeated, psychologists say that behavior has been reinforced. When the behavior leads to a negative outcome, psychologists refer to it as punishment. Two types of reinforcement and punishment have been described: positive and negative.
Positive reinforcement is generally regarded as synonymous with reward: When a behavior appears, something positive results. This leads to a greater likelihood that the behavior will recur. Negative reinforcement involves the termination of an unpleasant situation. Thus, if individuals have a headache, taking some kind of effective pain reliever leads to a satisfying outcome. In the future, when they have a headache, they are likely to take that pain reliever again. In positive and negative reinforcement, some behavior is likely to recur either because something positive results or something unpleasant stops.
Just as reinforcement comes in two versions, punishment takes two forms. Psychologists have identified positive punishment as the presentation of an unpleasant result when an undesired behavior occurs. By contrast, negative punishment occurs when something positive is removed. In both forms of punishment, an undesired behavior results in a negative consequence. As a result, the undesired behavior is less likely to recur in the future.
Many people mistakenly equate negative reinforcement with punishment because the word negative conveys the idea of punishment. In reality, a situation involving negative reinforcement involves the removal of a negative stimulus, leading to a more satisfying situation. A situation involving punishment always leads to an unwanted outcome.
Beginning with Watson and Skinner, psychology in the United States adopted a behavioral framework in which researchers began to study animals and people through conditioning. From the 1920s through the 1960s, many psychologists performed conditioning experiments with animals with the idea that what was true for nonhuman animals would also be true for humans. Psychologists assumed that the principles of conditioning are universal. Although many of the principles of learning and conditioning developed in nonhuman animal research pertain to human learning and conditioning, psychologists later realized that each species has distinct behavioral characteristics. Consequently, although the principles of conditioning may generalize from nonhuman animals to humans, researchers must consider the differences between species as well.
See also Aversive conditioning ; Classical conditioning ; Operant conditioning .
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Association for Behavior Analysis International, 550 W. Centre Ave., Portage, MI, 49024, (269) 4929310, Fax: (269) 492-9316, https://www.abainternational.org.