ABSTRACT
Thorndike (1911) laid the foundation for reinforcement theory. He stated in the law of effect that actions that lead to a “satisfying state of affairs” are repeated. According to this rather subjective notion, reinforcing stimuli strengthen certain behaviors by virtue of the fact that they produce a satisfying, or rewarding, state of affairs. This raises the question of what a satisfying state of affairs is. According to the law of effect, a satisfying state of affairs is produced by any stimulus that will reinforce behavior. Fortunately, this definitional circularity did not produce a satisfying state of affairs amongst reinforcement theorists. Over time, alternative conceptualizations of reinforcement emerged. For example, Hull (1943) focused not on subjective internal states, but rather on internal drive states (i.e., hunger). Within this framework, reinforcers reduce this drive state and establish internal homeostasis. Alternatively, the Skinnerian view (Skinner, 1958) is one of simple empiricism that does not rely on internal states. Rather, a reinforcer is a stimulus that increases the probability of an organism repeating a behavior that preceded the reinforcer’s presentation. Another approach involves Meehl’s (1950) principle of transsituationality. This principle assumes that reinforcers are effective at increasing the probability of responses across a broad range of behavioral situations. In contrast, Pavlov’s (1927) writings on reinforcement focused not on the behavioral responses that precede the reinforcing event, but rather on the elicitation of an unconditioned behavioral response by an unconditioned reinforcing stimulus. Pavlov further added that a conditioned response can be elicited by a previously neutral stimulus that has been paired with an unconditioned reinforcing stimulus. Finally, Bindra (1968, 1974) proposed an incentive-motivational model that incorporated many of the previous notions regarding reinforcement. This model asserts that both unconditioned and conditioned reinforcing stimuli are endowed with response eliciting and response strengthening properties that are characterized by approach, contact, and consummatory behaviors.
