Operant Conditioning

Description of the Strategy

Prior to the 1930s, behavioral psychology focused on the study of behaviors reliably elicited by unconditioned stimuli. In contrast to the study of classical (respondent) conditioning, in which an organism (“involuntarily”) responds to its environment almost reflexively, the study of operant conditioning, in which an organism (“voluntarily”) emits a behavior or acts/ operates on its environment, proposed that consequences, or events following a behavior rather than antecedent eliciting events, change the probability of that behavioral occurrence. Popularized by the research and publications of B. F. Skinner, operant conditioning works according to a three-term contingency involving the following terms: (1) the circumstances under which the organism acts (stimulus/antecedent), (2) the emitted behavior, and (3) the consequences of the emitted behavior. Although Skinner admired Pavlov's studies of classical conditioning, he believed that this explanation of behavior was severely limited because most behaviors are not elicited by a known stimulus. Furthermore, he believed that describing the consequences of behavior more accurately and usefully explains behaviors.

Skinner's ideas on behavior were greatly influenced by E. L. Thorndike's studies of how nonreflexive animal behaviors may be modified according to experience. Skinner's theories followed in the wake of Thorndike's Law of Effect, which stated that response probability is increased by “satisfying” consequences and decreased by “annoying” consequences. In addition, Charles Darwin's influence on Skinner's theory is evident in the parallels between the theory of natural selection and operant conditioning. In the same fashion that traits contributing to an organism's survival and species propagation are selected, consequences of available operant responses result in the strengthening or maintaining of some behaviors and the elimination or extinction of others.

Discussion of operant conditioning involves a closer examination of each of Skinner's three terms: stimulus/antecedent, behavior, and consequence. Because the most notable difference between operant conditioning and classical/respondent conditioning involves the role of behavioral consequences, this third term will be presented first. In operant conditioning, the consequences of an emitted behavior may either increase or decrease the probability of the event recurring in the future. Consequences may be divided into two distinct classes: reinforcers and punishers. Reinforcers are stimuli that follow a response, thereby increasing the probability that the response will recur in the future. Punishers are stimuli that follow a response and decrease the probability that the response will recur in the future.

Often mistakenly equated with rewards, reinforcers are not inherently pleasant and are context dependent (e.g., the candy bar that reinforces the hungry child may be punishing for the child who just ate a large dinner). Whereas rewards do not necessarily increase the probability that a response will recur in the future, reinforcers, by definition, must. Reinforcers may be categorized according to whether or not learning is required for them to increase response probability. Primary reinforcers are stimuli that are inherently reinforcing. Stimuli that meet biological needs (e.g., [Page 924]sexual gratification, food) are common examples. Generalized reinforcers are learned reinforcers that increase a wide variety of behaviors due to their cultural value (e.g., money, power, intelligence). Secondary reinforcers are stimuli that, while not inherently reinforcing, acquire the ability to increase response probability via pairing with primary or generalized reinforcers through classical conditioning (e.g., stickers used to reinforce good schoolwork). These objects are not inherently reinforcing, but through their association with other reinforcers such as intelligence, praise, and even money, they come to increase the probability of the events preceding reinforcement (e.g., studying, working hard).

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