In early part of the 20th century the powerful voice of John B. Watson had an enormous impact on academic psychology and the general public. During more recent years, B.F. Skinner exerted a comparable influence and advocated some of the same reforms. Skinner was an ardent behaviourist, convinced of the importance of objective method, experimental vigor and the capacity of elegant experimentation and inductive science to solve the most complex behaviour problems. He applied his concepts and methods to the major concerns of out time both practical and theoretical.
Skinner's position often has been described as a stimulus-response theory, but he repudiated this label on two grounds. First, his approach depends on the connection between a response and a subsequent reinforcing event, and not a stimulus and a subsequent response. Skinner concluded that there are no controlling or elicting stimuli for most behaviours: rather, the hallmark of skinner's operant conditioning is that control resides in the consequences of behaviour. Second, skinner has been distinguished by a distaste for formal theory. The goal of skinner's science is the control, prediction and interpretation of behaviour-a goal believed to be attainable because of the assumed lawfulness of behaviour.
Personal History
Skinner was born in 1904 and raised in Swquehann, Pennsylvania, in a warm and stable family setting. As an undergraduate he attended a small liberal arts school, Hamilton College, where he majored in English and determined to become a writer. Skinner received his PhD in 1931 and spent five post doctoral years working in Crozier's laboratory, the last three of which as a Junior Fellow, Harvard's most prestigious position for a young scholar. Crozier was one of a number of rigorous biologists who influenced skinner's thought. Others include Jacques Loob, C.S. Sherrington, and Ivan Pavlov. Among major psychologists in his intellectual lineage are John B. Watson and E.L. Thorndike. His first academic position was at the University of Minnesota where he moved in 1936, the nine subsequent years at Minnesota were remarkably productive and established skinner as one of the major experimental psychologists of the time. Following a brief stay at Indiana he returned to Harvard for the duration of his career. During these years skinner was accorded many honors including the distinguished scientific award of the American Psychological Association, membership in the National Academy of Sciences, the gold medal award of the American Psychological Foundation, serving as the William James Lecturer at Harvard and receipt of the President's medal of science. B.F. Skinner died of leukemia on August 18, 1990, only eight days after receipt of the only award the American Psychological Association had given for outstanding lifetime contribution to psychology.
General Considerations
Skinner's work is based on some basic assumptions and attitudes.
Lawfulness of Behaviour
Although the assumption that behavour is lawful is implicit in all psychological research it is often not explicit and many of its implications remain unrecognized. Skinner was the first person to place emphasis on the orderliness of behaviour, and communicate this belief to a large segment of the society. Skinner strongly believed that the principle of determinism applies to human beings. According to him behaviour is a product of forces assumed that behaviour was lawful, skinner drew out the implications of this assumption so that the ordinary person could understand them. The assumption that all behaviour is lawful clearly implies the possibility of behaviour control. All that is required is to manipulate these conditions that influence or result in a change in behaviour. Skinner's interest in behaviour stems from a curiosity of how behaviour works, and on intense desire to go about the job of manipulating.
Functional analysis
Skinner believed that a functional analysis is most appropriated to achieve the control of behaviour. By a functional analysis Skinner meant an analysis of behaviour in terms of cause and effect relationships, where the causes themselves are controllable.
Skinner consistently argued that behaviour can best be studied by considering how it is related to antecedent events. He also argued that in a functional analysis of behaviour there is no necessity to talk about mechanisms operating within the organism. Behaviour can be explained and controlled purely by the manipulation of the environment that contains the behaving organisms, and there is no need to take the organism apart of make any inferences about the events that are going on inside the organism.
Skinner's approach was based on the assumption that behaviour is orderly and that our primary purpose is to control it. This control can be achieved best by lawfully relating independent variables or inputs into the organism to dependent variable or out puts of the organism and the controlling subsequent behaviour by the manipulation of those same inputs (environmental events) in such a way as to obtain a particular output (response).
Structure of Personality
Skinner focused primarily on modifiable behaviour. His emphasis is on control of behaviour. Control is achieved only through modification: control implies that the environment can be varied in order to bring about different behaviour patterns.
Skinner did not claim that an individual's behaviour is only a product of the environment. He simply de-emphasized the practical importance of biological variability because in a purely behaviour science, this variability cannot easily be placed under behavioural control.
In selecting response variable, Skinner was primarily concerned with their simplicity and their lawful or regular association with environmental variation. The major classification that skinner suggested is the distinction between operant and respondent. This distinction primarily involves the difference between responses that are elicited and those that are emitted. The focus of skinner's concern is on the operant that is emitted in the absence of any elictiong stimulus. A respondent, on the other hand, is elicited by a known stimulus and is best illustrated by a response such a knee-jerk reflex where there is a known and relatively invariable response associated with a specified stimulus.
Dynamics of Personality
Skinner recognized that a person does not always exhibit the same behaviour to the same degree when in a constant situation. In as much as behaviour tends to be highly variable in some situations, an internal force is assumed to account for their variability. Skinner believed that even when behaviour shows this type of variability it is still unnecessary and often misleading to postulate an internal energizing force. Skinner treated the variability in the vigor of behaviour as a direct causal consequence of the variation in an independent variable.
Certain variables affect the probability of occurrence of whole groups of behaviour patterns E.g. Thrist. Thrist can be increased by several different operations and in turn may influence a number of different responses. Each of these operations will increase the animal's thirst and increase the likelihood that the animal will engage in one or more group of activities all of which are affected by this group of operations. Thus, an animal will perform a learned response more vigorously, if it produced water drink water more vigorously choose water instead of food, or any other response that was followed by water in the past. Thus, certain operations tend to increase the occurrence of certain responses.
Skinner employed a set of concepts that might be called dynamic or motivational. These concepts, were employed to account for the variability of behaviour in otherwise constant situations. In Skinner's system, they occupy a distinct category because they relate groups of responses to groups of operations, not because they are equated with energy states, purpose or any other condition that implies they are causal antecedents of behaviour.
Development of Personality
Skinner believed that an understanding of personality will develop from a consideration of the behavioural development of the human organism in continuing interaction with the environment. A key concept within skinne's system is the principle of reinforcement.
Classical Conditioning
To reinforce behaviour is to carry out a manipulation that changes the probability of occurrence of that behaviour in the future. The finding that certain operations change the probability of occurrence of responses in a lawful manner is credited primarily to two early leaders in the study of behavioural modification, I. Pavlov and E.L. Thorndike.
Pavlov discovered the principle of reinforcement as it applies to classical conditioning. Suppose on a number of occasions a bell is sounded in the presence of a hungry dog and is immediately followed by the presentation of meat to the dog. Though the dog salivates only when the meat is presented during the first few trails, later, salivation begins to occur as soon as the bell is sounded; before the presentation of the meat. At this stage the salivary response is conditioned to the sound of the bell. Here, the presentation of the meat immediately following the sound of the bell is the critical operation responsible for this conditioning. Thus the presentation of meat is a reinforcement operation, and because its presentation increases the chances of salivation, it is classified as a positive reinforcer, and the sounding of the bell is the conditioned stimulus. Now, if the bell is sounded and is not followed by meat, which is the reinforcing stimulus, the conditioned response, salivating at the sound of the bell gets extinguished. That is, its frequency of occurrence and its magnitude decline, with successive soundings of the bell, until finally no salivation is elicited by the bell at all. The conditioned responsed is then completely extinguished.
Skinner accepted the existence of classical conditioning and its dependence on the principle of reinforcement. But he was more interested in another type of learning, which was first systematically investigated by Thorndike, and is called instrumental or operant conditioning.
Operant Conditioning
An operant is a response that operates on the environment and changes it. The change in the environment affects the subsequent occurrence of the response. In operant conditioning, the reinforcer is not associated with the response that produces the reinforcement. When an operant response is conditioned, it is essential that the reinforcer be presented after the occurrence of the response. Skinner proposed the empirical law of effect. That is, a reinforcing stimulus is an event that increases the frequency of behaviour with which it is paired.
Next, Skinner proposed that organisms can learn complicated behaviours through shaping, using the principle of successive approximations. We start by reinforcing a behaviour that is a first step toward the final behaviour and then gradually reinforce successively closer approximations to the final behaviour. Through this process, organisms can acquire extremely complicated behaviours.
A punishing stimulus is an aversive stimulus, which, when occurring after an operant response, decreased the future likelihood of that response. A punishment is not the same as a negative reinforcer. Reinforcement increases the likelihood of occurrence of a behaviour with which it is paired, and a punishment decreases the likelihood of behaviour. Behaviour can be reinforced by the removal of an aversive stimulus, in which case we refer to a negative reinforcer.
Skinner argued that personality is a collection of behaviour patterns and the development of personality is the development of these behaviour patterns Skinner believed that we can predict, control and explain these developments by seeing how the principle of reinforcement has worked to account for the present day behaviour of an individual as a result of the reinforcement of previous responses.
Schedules of Reinforcement
If a response is strengthened by presenting a reinforcement on each occasion that the response occurs, it is known as continuous response. If the reinforcement is contingent on an interval of time, it is referred to as interval reinforcement; if this interval is unchanging we have fixed interval reinforcement schedule. Instead of providing reinforcement following a constant interval of time, it can be provided according to an intermittent or variable-interval schedule. Here, although the reinforcement may be available on the average at five-min intervals, the actual interval will vary randomly around this average. Thus, at each moment there is a low and constant probability that reinforcement is available. Under these conditions the organism respond with a steady rate of response. Most of these responses are not reinforced, but those that are reinforced serve to maintain the overall response rate. If the response is no longer reinforced, the response again extinguishes, but it does so at a much slower rate than when reinforcement was continuous.
Another type is the ratio-reinforcement schedule. Here the reinforcement is determined only b the number of responses that have been emitted since last reinforcement. This would be referred to as fixed-ratio reinforcement or the number might vary on a random basis, so that reinforcement might on the average be given after every fifth response by in actuality be randomly distributed around this average. This would be called a variable-ratio schedule.
The importance of these various schedules is that on the one hand they show correspondence to many learning situations of interest to personality investigator. On the other hand they relate to particular patterns of acquisition and extinction of the responses being learned.
Superstitious Behaviour
It is not necessary for a response to physically produce the reinforcement for it to be reinforced. Ordinarily, for experimental purposes, an experimental apparatus is set up so that a reinforcer is produced by a response through its effects on the apparatus. However, free reinforcement can be delivered quite independently of the subject's behaviour. When this 'free' reinforcement is delivered that subject may have been involved in a particular kind of behaviour or movement sequence. Although, that behaviour did not produce the reinforcer, it was immediately followed by a reinforcer.
Summary
Skinner contends that behaviour is lawfully determined, predictable and environmentally controlled. Further, he contends that the fundamental principles underlying human behaviour are most readily discerned by studying lower organisms. Skinner has focused most of his scientific attention upon operant behaviour. He has shown quantification of such behaviour, indicated the lawful control of various reinforcement schedules, conditioned reinforcers, and aversive stimuli, demonstrated the shaping of operant behaviour through successive approximation and indicated its extension and appropriate adaption to new stimuli (stimulus generalization and discrimination). He also attempted to modify abnormal behaviour (a learnt response) by manipulation of the environment (stimuli) by the techniques of operant and respondent classical conditioning.
Personal History
Skinner was born in 1904 and raised in Swquehann, Pennsylvania, in a warm and stable family setting. As an undergraduate he attended a small liberal arts school, Hamilton College, where he majored in English and determined to become a writer. Skinner received his PhD in 1931 and spent five post doctoral years working in Crozier's laboratory, the last three of which as a Junior Fellow, Harvard's most prestigious position for a young scholar. Crozier was one of a number of rigorous biologists who influenced skinner's thought. Others include Jacques Loob, C.S. Sherrington, and Ivan Pavlov. Among major psychologists in his intellectual lineage are John B. Watson and E.L. Thorndike. His first academic position was at the University of Minnesota where he moved in 1936, the nine subsequent years at Minnesota were remarkably productive and established skinner as one of the major experimental psychologists of the time. Following a brief stay at Indiana he returned to Harvard for the duration of his career. During these years skinner was accorded many honors including the distinguished scientific award of the American Psychological Association, membership in the National Academy of Sciences, the gold medal award of the American Psychological Foundation, serving as the William James Lecturer at Harvard and receipt of the President's medal of science. B.F. Skinner died of leukemia on August 18, 1990, only eight days after receipt of the only award the American Psychological Association had given for outstanding lifetime contribution to psychology.
General Considerations
Skinner's work is based on some basic assumptions and attitudes.
Lawfulness of Behaviour
Although the assumption that behavour is lawful is implicit in all psychological research it is often not explicit and many of its implications remain unrecognized. Skinner was the first person to place emphasis on the orderliness of behaviour, and communicate this belief to a large segment of the society. Skinner strongly believed that the principle of determinism applies to human beings. According to him behaviour is a product of forces assumed that behaviour was lawful, skinner drew out the implications of this assumption so that the ordinary person could understand them. The assumption that all behaviour is lawful clearly implies the possibility of behaviour control. All that is required is to manipulate these conditions that influence or result in a change in behaviour. Skinner's interest in behaviour stems from a curiosity of how behaviour works, and on intense desire to go about the job of manipulating.
Functional analysis
Skinner believed that a functional analysis is most appropriated to achieve the control of behaviour. By a functional analysis Skinner meant an analysis of behaviour in terms of cause and effect relationships, where the causes themselves are controllable.
Skinner consistently argued that behaviour can best be studied by considering how it is related to antecedent events. He also argued that in a functional analysis of behaviour there is no necessity to talk about mechanisms operating within the organism. Behaviour can be explained and controlled purely by the manipulation of the environment that contains the behaving organisms, and there is no need to take the organism apart of make any inferences about the events that are going on inside the organism.
Skinner's approach was based on the assumption that behaviour is orderly and that our primary purpose is to control it. This control can be achieved best by lawfully relating independent variables or inputs into the organism to dependent variable or out puts of the organism and the controlling subsequent behaviour by the manipulation of those same inputs (environmental events) in such a way as to obtain a particular output (response).
Structure of Personality
Skinner focused primarily on modifiable behaviour. His emphasis is on control of behaviour. Control is achieved only through modification: control implies that the environment can be varied in order to bring about different behaviour patterns.
Skinner did not claim that an individual's behaviour is only a product of the environment. He simply de-emphasized the practical importance of biological variability because in a purely behaviour science, this variability cannot easily be placed under behavioural control.
In selecting response variable, Skinner was primarily concerned with their simplicity and their lawful or regular association with environmental variation. The major classification that skinner suggested is the distinction between operant and respondent. This distinction primarily involves the difference between responses that are elicited and those that are emitted. The focus of skinner's concern is on the operant that is emitted in the absence of any elictiong stimulus. A respondent, on the other hand, is elicited by a known stimulus and is best illustrated by a response such a knee-jerk reflex where there is a known and relatively invariable response associated with a specified stimulus.
Dynamics of Personality
Skinner recognized that a person does not always exhibit the same behaviour to the same degree when in a constant situation. In as much as behaviour tends to be highly variable in some situations, an internal force is assumed to account for their variability. Skinner believed that even when behaviour shows this type of variability it is still unnecessary and often misleading to postulate an internal energizing force. Skinner treated the variability in the vigor of behaviour as a direct causal consequence of the variation in an independent variable.
Certain variables affect the probability of occurrence of whole groups of behaviour patterns E.g. Thrist. Thrist can be increased by several different operations and in turn may influence a number of different responses. Each of these operations will increase the animal's thirst and increase the likelihood that the animal will engage in one or more group of activities all of which are affected by this group of operations. Thus, an animal will perform a learned response more vigorously, if it produced water drink water more vigorously choose water instead of food, or any other response that was followed by water in the past. Thus, certain operations tend to increase the occurrence of certain responses.
Skinner employed a set of concepts that might be called dynamic or motivational. These concepts, were employed to account for the variability of behaviour in otherwise constant situations. In Skinner's system, they occupy a distinct category because they relate groups of responses to groups of operations, not because they are equated with energy states, purpose or any other condition that implies they are causal antecedents of behaviour.
Development of Personality
Skinner believed that an understanding of personality will develop from a consideration of the behavioural development of the human organism in continuing interaction with the environment. A key concept within skinne's system is the principle of reinforcement.
Classical Conditioning
To reinforce behaviour is to carry out a manipulation that changes the probability of occurrence of that behaviour in the future. The finding that certain operations change the probability of occurrence of responses in a lawful manner is credited primarily to two early leaders in the study of behavioural modification, I. Pavlov and E.L. Thorndike.
Pavlov discovered the principle of reinforcement as it applies to classical conditioning. Suppose on a number of occasions a bell is sounded in the presence of a hungry dog and is immediately followed by the presentation of meat to the dog. Though the dog salivates only when the meat is presented during the first few trails, later, salivation begins to occur as soon as the bell is sounded; before the presentation of the meat. At this stage the salivary response is conditioned to the sound of the bell. Here, the presentation of the meat immediately following the sound of the bell is the critical operation responsible for this conditioning. Thus the presentation of meat is a reinforcement operation, and because its presentation increases the chances of salivation, it is classified as a positive reinforcer, and the sounding of the bell is the conditioned stimulus. Now, if the bell is sounded and is not followed by meat, which is the reinforcing stimulus, the conditioned response, salivating at the sound of the bell gets extinguished. That is, its frequency of occurrence and its magnitude decline, with successive soundings of the bell, until finally no salivation is elicited by the bell at all. The conditioned responsed is then completely extinguished.
Skinner accepted the existence of classical conditioning and its dependence on the principle of reinforcement. But he was more interested in another type of learning, which was first systematically investigated by Thorndike, and is called instrumental or operant conditioning.
Operant Conditioning
An operant is a response that operates on the environment and changes it. The change in the environment affects the subsequent occurrence of the response. In operant conditioning, the reinforcer is not associated with the response that produces the reinforcement. When an operant response is conditioned, it is essential that the reinforcer be presented after the occurrence of the response. Skinner proposed the empirical law of effect. That is, a reinforcing stimulus is an event that increases the frequency of behaviour with which it is paired.
Next, Skinner proposed that organisms can learn complicated behaviours through shaping, using the principle of successive approximations. We start by reinforcing a behaviour that is a first step toward the final behaviour and then gradually reinforce successively closer approximations to the final behaviour. Through this process, organisms can acquire extremely complicated behaviours.
A punishing stimulus is an aversive stimulus, which, when occurring after an operant response, decreased the future likelihood of that response. A punishment is not the same as a negative reinforcer. Reinforcement increases the likelihood of occurrence of a behaviour with which it is paired, and a punishment decreases the likelihood of behaviour. Behaviour can be reinforced by the removal of an aversive stimulus, in which case we refer to a negative reinforcer.
Skinner argued that personality is a collection of behaviour patterns and the development of personality is the development of these behaviour patterns Skinner believed that we can predict, control and explain these developments by seeing how the principle of reinforcement has worked to account for the present day behaviour of an individual as a result of the reinforcement of previous responses.
Schedules of Reinforcement
If a response is strengthened by presenting a reinforcement on each occasion that the response occurs, it is known as continuous response. If the reinforcement is contingent on an interval of time, it is referred to as interval reinforcement; if this interval is unchanging we have fixed interval reinforcement schedule. Instead of providing reinforcement following a constant interval of time, it can be provided according to an intermittent or variable-interval schedule. Here, although the reinforcement may be available on the average at five-min intervals, the actual interval will vary randomly around this average. Thus, at each moment there is a low and constant probability that reinforcement is available. Under these conditions the organism respond with a steady rate of response. Most of these responses are not reinforced, but those that are reinforced serve to maintain the overall response rate. If the response is no longer reinforced, the response again extinguishes, but it does so at a much slower rate than when reinforcement was continuous.
Another type is the ratio-reinforcement schedule. Here the reinforcement is determined only b the number of responses that have been emitted since last reinforcement. This would be referred to as fixed-ratio reinforcement or the number might vary on a random basis, so that reinforcement might on the average be given after every fifth response by in actuality be randomly distributed around this average. This would be called a variable-ratio schedule.
The importance of these various schedules is that on the one hand they show correspondence to many learning situations of interest to personality investigator. On the other hand they relate to particular patterns of acquisition and extinction of the responses being learned.
Superstitious Behaviour
It is not necessary for a response to physically produce the reinforcement for it to be reinforced. Ordinarily, for experimental purposes, an experimental apparatus is set up so that a reinforcer is produced by a response through its effects on the apparatus. However, free reinforcement can be delivered quite independently of the subject's behaviour. When this 'free' reinforcement is delivered that subject may have been involved in a particular kind of behaviour or movement sequence. Although, that behaviour did not produce the reinforcer, it was immediately followed by a reinforcer.
Summary
Skinner contends that behaviour is lawfully determined, predictable and environmentally controlled. Further, he contends that the fundamental principles underlying human behaviour are most readily discerned by studying lower organisms. Skinner has focused most of his scientific attention upon operant behaviour. He has shown quantification of such behaviour, indicated the lawful control of various reinforcement schedules, conditioned reinforcers, and aversive stimuli, demonstrated the shaping of operant behaviour through successive approximation and indicated its extension and appropriate adaption to new stimuli (stimulus generalization and discrimination). He also attempted to modify abnormal behaviour (a learnt response) by manipulation of the environment (stimuli) by the techniques of operant and respondent classical conditioning.
