Principle Of Reinforcement Research Paper

There is circularity in such a statement, as a stimulus event is judged to be a positive reinforcement to the extent that it actually increases the likelihood of the behavior that produced it. Thus, reinforcement is not quite the same as reward, since a reinforcer is defined in terms of what ‘works’ or functions to strengthen behavior, whereas a reward is identified by what an individual expresses a desire for, or enjoys. In practice, however, one selects reinforcements on the basis of prior experience, observation, and intuition that the planned consequence will be desired or enjoyable. When an organism will engage in a behavior that produces a consequence (food, praise, stimulation, or even apparently negative outcomes such as fatigue or annoying someone else) it is referred to as positive reinforcement; when an organism works actively to reduce or eliminate events currently in existence (such as cold, teacher demands, loneliness, boring activities), it is known as negative reinforcement.

Any previously neutral stimulus that signals the onset or further probability of a reinforcer comes to have reinforcing properties of its own, and is described as a secondary or conditioned reinforcer. Socially, money is the classic example. In applied contexts, a stimulus that has no value other than a designated rate of exchange with something desired is called a token reinforcement—often these are symbols such as poker chips or points that can later be exchanged for privileges.

1. History Of The Concept

Reinforcement is closely linked to evolutionary principles, in that it represents adaptive functioning with obvious survival implications, and applies to all species capable of benefitting from experience. Its origin as a formal principle of modern psychology derives from Thorndike’s (1927) Law of Effect: the occurrence of a ‘satisfying’ event ‘stamps in’ the behavior that was instrumental in producing it. Hull’s (1943) influential learning theory proposed that the increase is in the strength of the association between a prior stimulus (cue or context) and the response, with the mechanism underlying reinforcement being the reduction in a basic biological drive. However, many stimuli can serve as reinforcers when they have only incentive value (such as a sweet but non-nutritive substance).

Much past research has been devoted to the question of whether reinforcement is necessary for learning to occur; the present consensus is that it is not. The question, however, may be a spurious one, since it is difficult to imagine a behavior that has no consequences, and the positive nature of the outcome might be as simple as reducing constraints on the individual, or predicting future pleasures.

In the classical conditioning paradigm, Pavlov also used the term to refer to the ‘unconditioned stimulus’ (UCS: the stimulus that evokes the reflexive response). When this stimulus is regularly paired with (predicted by) a neutral stimulus, the latter comes to evoke a somewhat similar response. The UCS is thus considered reinforcement, since its occurrence increases the tendency to emit a response in the presence of a previously neutral stimulus. Of considerable theoretical and practical importance is the phenomenon that when the UCS is removed and the previously neutral stimulus presented repeatedly, the conditioned response eventually ceases to occur. This phenomenon, as well as the procedure of removing the UCS, is known as extinction. It has an exact parallel in instrumental conditioning: if the overt behavior no longer produces the positive outcome, its probability decreases. This process is not simply the opposite of reinforcement; it is not unlearning or forgetting, but learning to do something else.

Although central to both conventional instrumental and classical learning situations, the concept of reinforcement has acquired much of its practical, applied implication from Skinner’s (1969) paradigm of operant conditioning. The typical laboratory procedure is for a specific ‘operant’ response, such as the pressing of a lever or push button, to result in the automatic delivery of a small amount of food for a hungry animal. The operants studied have been discrete, simple responses that can be repeated easily by the subject. A vast body of experimental research has demonstrated that the form, intensity, and temporal pattern (rate) of responding is a function of the rule specifying the relationship between the operant response, its consequence, and the context in which the consequence occurs (referred to as the ‘three-term contingency’).

2. Contingency Principles

The effectiveness of this procedure for developing or maintaining a specified operant is influenced by the immediacy and predictability with which the reinforcement is delivered. Although it will slow the acquisition of new responses, the reinforcement need not be delivered after every response, an arrangement called a ‘partial schedule of reinforcement.’ The most common are ratio schedules, in which reinforcement is delivered after a specified number of responses; and interval schedules, in which reinforcement is delivered to the first response occurring after a predetermined period of time has elapsed. In the laboratory, these different schedules of reinforcement produce characteristic patterns of response rate. Analogies are often made with workplace contingencies; for example, if one is paid on a piecework basis it is a ratio schedule, whereas being paid every month is an interval schedule of reinforcement. Reinforcement can also be delivered after a variable number of responses or periods of time—gambling on a slot machine represents a variable ratio schedule.

Of greater importance for application is that partial schedules of reinforcement result in a behavior being highly resistant to extinction, such that the subject will persist in the behavior for long periods of time, even when the reinforcement has been withdrawn (extinction). In clinical situations one might think that a behavior is maladaptive as it is apparently not being reinforced and should therefore extinguish. If the individual’s history of reinforcement were known, however, it would be recognized that this behavior may have been reinforced sporadically in the past.

The precise form of any behavior can be determined by differential reinforcement, in which the criteria for exactly what response will result in reinforcement are carefully specified. By changing or narrowing these criteria gradually, a behavior can be ‘shaped’ into a specified configuration. Similarly, it is quite common in practice to reinforce differentially decreases in an undesirable behavior, or reinforce differentially alternative, more appropriate behaviors.

3. Limitations In Generalizing From The Laboratory

Despite the substantial body of knowledge derived from studies of animal behavior, the analogy between the operant laboratory and real life has limitations. Laboratory contingencies are contrived—unlike foraging in the wild, there is no intrinsic relationship between a lever press and obtaining food. There are many comparable artificial contingencies operating in everyday life, particularly work settings, in which a person is reinforced with money, food, or favors, for activities desired by the individual controlling these reinforcers. But more commonly our activities are intrinsically as well as socially rewarding, for instance, reading a book is reinforced by enjoyment of the story as well as by teacher approval, or climbing a mountain may be reinforced by a sense of accomplishment in addition to the admiration of friends.

It has long been debated that if an activity which is usually reinforced intrinsically is placed under an artificial external contingency (such as a monetary payment), this will later interfere with the intrinsic reward, such that once the artificial reward is withdrawn, the frequency of the behavior will drop below its previously (intrinsically) reinforced rate (see Carton and Nowicki 1998 for a discussion). There is also considerable overlap in practice between the concept of reinforcement and that of feedback—providing people with information regarding their task performance. Feedback too can impair performance, regardless of whether it provides information about success or failure, by directing attention to self rather than the task at hand.

Another major difference between reinforcement studied in the laboratory and the principles affecting human social behavior is that the verbal specification of a contingency can function much like an actual contingency. Thus, for example, people can be promised a reward for an activity and this will change their behavior. Skinner referred to this as ‘rule governed behavior,’ whereas more cognitively oriented theorists prefer to talk of expectancies. Bandura (1977), for example, argued that performance on a task depends partly on the expectation that a certain reward will be forthcoming (outcome expectancy). Another way an individual can learn about a potential contingency between a behavior and a reinforcer is to observe someone else being reinforced for an activity; this is known as vicarious reinforcement.

4. Motivation And Individual Differences

Most general behavior theories argue there is a link between reinforcement and emotion, for example, Staats’ (1996) A-R-D model, which proposes that stimuli serving as reinforcers (R) have simultaneous attitudinal (A) value (can elicit emotion) and discriminative stimulus (D) functions (can serve as a cue for approach). As active approach behavior and reward systems are linked in terms of neural processes, there are plausible biological mechanism for personality differences in the degree to which a given individual is responsive to positive outcomes. Relative sensitivity to reward over punishment may also be a characteristic of individuals exhibiting certain clinical syndromes, such as Attention Deficit Hyperactivity Disorder (ADHD), conduct disorder, and recent onset schizophrenia. There are also individual differences in preference for a small but immediate reinforcer as opposed to a larger, but more delayed reinforcer, a pattern that is generally considered to be maladaptive and detrimental to individual success. Humans are more influenced by reinforcers they have chosen than those arbitrarily selected by someone else. When environmental conditions deprive an organism of the opportunity to perform a particular behavior that would be engaged in a free choice situation, it will perform other activities in order to gain access to that behavior, a phenomenon sometimes referred to as the Premack (1965) principle.

Where reinforcement is artificial, such as a socially determined prize for a job well done, humans learn from prior experience the standard of performance that deserves to be rewarded. Even young children are unlikely to appreciate a reward given for performance that is below their own standard. Thus, although self-reinforcement is often included as a treatment component for enhancing self-control, it is unlikely to be influential over and above the intrinsic satisfaction of accomplishing one’s own goals. Furthermore, if the outcomes achieved after much effortful behavior are less positive than expected, people tend to reevaluate the outcome in an upward direction (Lawrence and Festinger 1962).

5. Reinforcement As Behavioral Regulation

Much of current reinforcement theory in the operant tradition is concerned not with understanding the motivational features of reinforcement, but with predicting the effect on the distribution of available activities of different conditions of reinforcement. Neobehavioral theories that relate reinforcement to motivation (e.g., need reduction), have given way to economic-type theories that consider the sum total of potential behaviors in a situation as well as the sum total of reinforcements. One of the most important observations underlying this approach is that if there is more than one operant being reinforced (concurrent operant schedules), animals will distribute their responses more or less in proportion to the amount of reinforcement available to each one. This is known as Herrnstein’s matching law (see Noll 1995 for a discussion).

In answer to the apparent anomalies discussed in Section 3, reinforcement is depicted as a homeostatic principle, referring to how an organism must adjust its actions to meet the demands of the environment. An organism will normally distribute its activities so as to minimize the demands (e.g., effortfulness of the response) and maximize opportunities, and this optimum—when there is unconstrained choice—is known as the behavioral ‘bliss point.’ Once reinforcement is seen in this light, it gives credence to applied approaches in which there is an emphasis on enhancing choices and opportunities for individuals in otherwise deprived environments, or those with limited responses in their repertoire.

Theories emphasizing behavioral regulation propose that contingencies serve to constrain the organism’s free flow of behavior. Given the wide range of behavioral choices available to individuals in natural situations, it is logical that removing a reinforcement for one behavior will not be successful in reducing this behavior unless another, more socially desirable, behavior is able to be reinforced. Clinical research has repeatedly demonstrated the value of reinforcing more appropriate alternatives. Since the systems or economic model emphasizes that increases in one behavior must inevitably be accompanied by decreases in others, extinguishing undesirable behavior and reinforcing appropriate responses may be two sides of the same coin.

6. Conclusions

While context behavior outcome contingencies are essential elements in the shaping and development of new skills, the reinforcing event itself has complex influences on human behavior and often serves as a cue initiating other activities. The effects of reinforcement are relative—related to the levels of reinforcement for other possible behaviors—which has important implications for designing environments that will support socially desirable activities. That there are motivational and emotional properties of reinforcement should not be underestimated, such as experiencing success, the relief of reduction in anxiety, or the satisfaction of a craving. There are also cognitive properties, with the history of availability being judged by the individual and influencing expectancies regarding the relative outcomes of different actions. Past experience with certain types of contingencies and deprivation experiences influence the way an individual will respond to a given reinforcement contingency. The relatively simple idea that all behavior has a function—achieves some outcome for an organism—and that function regulates or controls the behavior, is a critical insight for analyzing behaviors that one wishes to change. However, the reverse of this principle—that we can artificially manipulate behavior by managing its consequences—has proved more complex than it appears, partly perhaps because humans at least, resist the experience that they are being deliberately controlled.

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