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Contingencies of reinforcement: A theoretical analysis
BEHAVIORTHERAPY(1970) 1, 260-264
Critical Notice
SKINNER, B. F., Contingencies of Reinforcement: A Theoretical Analysis. New York:
Appleton-Century-Crofts, 1969. xiv + 319 pp. $6.00. H. J. EYSENCK University of London Institute of Psychiatry
A book by B. F. Skinner is always an event; the present one is half an event because it is simply a collection of lectures and papers given at various times to various audiences and brought together here under a title which may promise more than it fulfills. T h e book certainly deals with contingencies of reinforcement; it is the subtitle " A Theoretical Analysis" which may cause one to wonder. Skinner complains in his preface that, as a consequence of the publication of his 1950 paper " A r e Theories of Learning N e c e s s a r y ? " , his position has been described as a grand antitheory. H e argues that this is a misconception; in his definition, theory meant "an explanation of an observed fact which appeals to events taking place somewhere else, at some other level of observation, described in different terms, and measured, if at all, in different dimensions." T h e prime example of such methods as he disapproves of is the hypothetico-deductive method. " B e h a v i o r is one of those subject matters which do not call for hypothetico-deductive methods. Both behavior itself and most of the variables of which it is a function are usually conspicuous . . . . if hypotheses commonly appear in the study of behavior, it is only because the investigator has turned his attention to inaccessible e v e n t s - - s o m e of them fictitious, others irrelevant . . . . we can avoid hypothetico-deductive methods in all these fields by formulating the data without reference to cognitive processes, mental apparatuses, or traits. Many physiological explanations of behavior seem at the moment to call for hypotheses, but the future lies with techniques of direct observation which will make them un-necessary." Every dog must have its day, and I suppose it would be churlish to complain of Skinner's tendency to hurl unqualified obiter dicta at the world in this fashion. H e may, of course, be right; the point is that he never argues the point but assumes what requires to be demonstrated. 260
CRITICAL NOTICE
261
Peter Medawar, F. R. S. and Nobel Prize winner for his work in biology, has presented the argument in favor of the hypothetico-deductive method and against Skinner's purely inductive approach, in his book on The Art of the Soluble; it seems a pity that Skinner could not have elaborated his point (which obviously is very important to him) in such a way as to meet the arguments on the other side. It is, of course, characteristic of his writing that he constantly presents challenging statements without empirical or even argumentative support; but does this do a service to science or to Skinner's own position? This extends to what one must regard as misrepresentations of fact. Thus he says that "research which is not designed to test hypotheses . . . appears perfectly reasonable to physicists, chemists, and most biologists." Medawar has quoted much evidence to show that this is not so; Skinner only gives us his unsupported statement. When he does present arguments, there are patently erroneous. Thus, for instance, he maintains that nontheoretical approaches are more valuable because "few data have b e c o m e useless because a theory they were designed to test has been discarded." Is it true that all the experimental results derived from attempts to test N e w t o n ' s theories were discarded when his theory became in fact untenable? Facts once established may be reinterpreted, but scientists do not throw them away like a woman might throw away a hat because it has gone out of fashion. This sort of argument may be exhilarating and provocative, but it is not very helpful to the young student who may not realize how one-sided a picture Skinner is presenting of the situation. This is a pity precisely because Skinner, in my opinion, has a point. The hypothetico-deductive method becomes more and more appropriate the more we kaow about the subject; Baconian induction may be more helpful in an earlier phase. Such a modest truth tends to get lost in the intemperate language favored by Skinner and his adherents. A similar tendency to cut the Gordian knot is observed in his recommendation to students faced with the very extensive literature they have to read. This is what Skinner advises: " A field of specialisation helps, but most fields are still large. Some principle of selection is needed, and a useful guide is the significance of the variables studied. A glimpse of the coordinates of the graphs in an article will usually suffice. A good rule of thumb is as follows: do not spend much time on articles in which changes in behavior are followed from trial to trial or in which graphs show changes in the time or number of errors required to reach a criterion, or in amount remembered, or in percent of correct choices made, or which report scores, raw or standard. Sometimes a look at the apparatus will help. Dimensions are probably
262
H.J.
EYSENCK
suspect if the work was done with mazes, T-mazes, jumping stanUs, or memory drums." Following these rules would certainly make life easier for the student; it would also eliminate most of the work considered important and interesting by non-Skinnerians! One of Skinner's main claims for what he insists on calling "the experimental analysis of behavior" is that "the specific method which has made it successful in the laboratory makes it almost immediately available for practical purposes. It is not concerned with testing theories but with directly modifying behavior," and he goes on to point out that "the two fields in which an experimental analysis of behavior has already yielded the most extensive technology (education and psychotherapy) are those closest to psychology itself. .... This quotation reflects two errors frequently encountered but nevertheless not presenting a true state of affairs. The technologies in question may have benefitted by the theoretical underpinning given to them by Skinner, but their inception antidates his own contribution. Teaching machines, to take but one example, were invented and developed by Pressey long before Skinner turned his interest to this field; his own contribution on the theoretical side consisted mainly in the almost certainly mistaken view that small steps of progression and almost invariable positive reinforcement were necessary and desirable ingredients in the programming of a successful teaching machine. The evidence seems to go clearly counter to this view, and, while I am willing to believe that teaching machines may in due course make a contribution to education, ! find that the evidence demonstrating their superiority over ordinary teaching methods is no better than that demonstrating the value of Freudian psychotherapy. Premature congratulations would not seem to be in order. The same may be said with respect to token economies, as applied to the rehabilitation of criminals and of chronic psychotics. This method was first advocated and put into practice by Alexander Maconochie, who was made Superintendent of the convict settlement of Norfolk Island in 1840 and later on became Governor of Birmingham Prison in England. His introduction of what he called "the mark system of prison discipline" consitutes a milestone in the field of behavior modification, and is still the best available evidence for the successful working of a token economy. To suggest that such advances are contingent upon laboratory work on operant conditioning suggests a lack of historical sophistication; it would have been very interesting to have been given Skinner's views of the work of his eminent predecessor! Skinner pays little attention to individual differences although he does not deny their existence. He simply refers them to the organism's history
CRITICAL NOTICE
263
of reinforcement. " T he complex system we call an organism has an elaborate and largely unknown history which endows it with a certain individuality"; the impressive work on genetic factors does not receive a mention, let alone a review. For Skinner, what does not interest him does not exist. This makes for a cohesive and highly motivated school, but it does not make for good scholarship or--ultimately--good science. To say this is, of course, not to deny that this volume contains much that is valuable and important. Like most people, Skinner is at his best when writing about the things that interest him, and that means, in the present context, that he is concerned with the more general problems of behavior and its control through the management of reinforcement contingencies. His discussions are pithy, often witty, and always well written: when Skinner gets away from the ugliness of operant jargon he is one of the most attractive writers in psychology. Quite often he slips in a remark which throws an entirely new light on an old topic. Consider, for instance, the following point made quite incidentally: "Recent work by Harlow and others on the behavior of infant monkeys is said to be particularly significant for human behavior because monkeys are primates; but so far as a behavioral repertoire is concerned, the human infant is much closer to a kitten or puppy than to an arboreal monkey. The kinship is not in the line of descent, but in the contingencies of survival. The monkey is more likely to survive if infants cling to their mothers, scream and run if left alone, and run to their mothers when frightened. The human baby cannot do much of this, and if it could, the behavior would have no great survival value in a species in which the mother leaves the young while foraging since highly excitable behavior in the infant would attract predators. Mild activity in hunger or physical distress and clinging and sucking when hungry are no doubt important for the human infant, but they lack the extremity of the responses of the infant monkey." This surely throws an entirely new light on Harlow's work and its relevance to human behavior. Or consider this important point which is so often forgotten by the builders of modern Utopias: "Men are happy in an environment in which active, productive, and creative behavior is reinforced in effective ways. The trouble with both affluent and welfare societies is that reinforcers are not contingent on behavior. Men who are not reinforced for doing anything do little or nothing. This is the 'contentment' of the Arcadian idyll and of the retired businessman. It may represent a satisfaction of needs, but it raises other problems. Only when we stop using reinforcers to allay the needs can we begin to use them to 'fulfill man's nature' in a much more important sense." At the other end of the scale, however, he frequently makes remarks which strike one as unlikely and rather difficult
264
H. J. E Y S E N C K
to prove. He accounts for Don Giovanni's sexual behavior in terms of a particularly effective schedule of reinforcement. "A moderate susceptibility to sexual reinforcement should be enough to make every attractive girl the occasion for attempted seduction if early successes are favorably programmed. An effective variable-ratio schedule should maintain the behavior at a high level even in a person who is sexually below normal, in which case it might be tempting to argue that the above-normal behavior shows 'compensation.'" To interpret the behavior of literary or mythological figures in terms of one's pet theory puts Skinner on the same plane as Freud or Jones, who interpreted Hamlet in terms of the Oedipus complex. This may be amusing to the literati, but it tends to take us out of science. In short, this book demonstrates one of the odd things about modem psychology, to wit, that people write well and reasonably about the things they know, and tend to talk nonsense about the things they don't know and don't care about. What is odd is not perhaps that this should be so, but rather that psychologists should ever go outside their own field of competence in this manner. A physicist working in cryogenics wouldn't dream of criticizing the methods or results of workers in cosmology, and a rheologist wouldn't consider it his job to discuss the things done by electronics experts. It is only in psychology that you tend to get this omniscience complex, this belief that only what you are doing is worth doing, and that everyone outside the narrow group is either misguided or foolish. The work that Skinner is doing is clearly important and valuable, both on the experimental and the applied level; why must he spoil a good story by implying that this is the whole of psychology, and that his methods and predilections are the only tolerable ones? This would have been a very much better book if Skinner had concentrated on the tremendous positive contribution he has made to psychology; there may be just one or two important things to be done which do not depend on the contingencies of reinforcement; and the methodology favored by Skinner, while obviously very fruitful in his hands, may with advantage be supplemented by others, in different hands and for different purposes. General verdict: brilliant but erratic; could do better with a little discipline.
Critical Notice
SKINNER, B. F., Contingencies of Reinforcement: A Theoretical Analysis. New York:
Appleton-Century-Crofts, 1969. xiv + 319 pp. $6.00. H. J. EYSENCK University of London Institute of Psychiatry
A book by B. F. Skinner is always an event; the present one is half an event because it is simply a collection of lectures and papers given at various times to various audiences and brought together here under a title which may promise more than it fulfills. T h e book certainly deals with contingencies of reinforcement; it is the subtitle " A Theoretical Analysis" which may cause one to wonder. Skinner complains in his preface that, as a consequence of the publication of his 1950 paper " A r e Theories of Learning N e c e s s a r y ? " , his position has been described as a grand antitheory. H e argues that this is a misconception; in his definition, theory meant "an explanation of an observed fact which appeals to events taking place somewhere else, at some other level of observation, described in different terms, and measured, if at all, in different dimensions." T h e prime example of such methods as he disapproves of is the hypothetico-deductive method. " B e h a v i o r is one of those subject matters which do not call for hypothetico-deductive methods. Both behavior itself and most of the variables of which it is a function are usually conspicuous . . . . if hypotheses commonly appear in the study of behavior, it is only because the investigator has turned his attention to inaccessible e v e n t s - - s o m e of them fictitious, others irrelevant . . . . we can avoid hypothetico-deductive methods in all these fields by formulating the data without reference to cognitive processes, mental apparatuses, or traits. Many physiological explanations of behavior seem at the moment to call for hypotheses, but the future lies with techniques of direct observation which will make them un-necessary." Every dog must have its day, and I suppose it would be churlish to complain of Skinner's tendency to hurl unqualified obiter dicta at the world in this fashion. H e may, of course, be right; the point is that he never argues the point but assumes what requires to be demonstrated. 260
CRITICAL NOTICE
261
Peter Medawar, F. R. S. and Nobel Prize winner for his work in biology, has presented the argument in favor of the hypothetico-deductive method and against Skinner's purely inductive approach, in his book on The Art of the Soluble; it seems a pity that Skinner could not have elaborated his point (which obviously is very important to him) in such a way as to meet the arguments on the other side. It is, of course, characteristic of his writing that he constantly presents challenging statements without empirical or even argumentative support; but does this do a service to science or to Skinner's own position? This extends to what one must regard as misrepresentations of fact. Thus he says that "research which is not designed to test hypotheses . . . appears perfectly reasonable to physicists, chemists, and most biologists." Medawar has quoted much evidence to show that this is not so; Skinner only gives us his unsupported statement. When he does present arguments, there are patently erroneous. Thus, for instance, he maintains that nontheoretical approaches are more valuable because "few data have b e c o m e useless because a theory they were designed to test has been discarded." Is it true that all the experimental results derived from attempts to test N e w t o n ' s theories were discarded when his theory became in fact untenable? Facts once established may be reinterpreted, but scientists do not throw them away like a woman might throw away a hat because it has gone out of fashion. This sort of argument may be exhilarating and provocative, but it is not very helpful to the young student who may not realize how one-sided a picture Skinner is presenting of the situation. This is a pity precisely because Skinner, in my opinion, has a point. The hypothetico-deductive method becomes more and more appropriate the more we kaow about the subject; Baconian induction may be more helpful in an earlier phase. Such a modest truth tends to get lost in the intemperate language favored by Skinner and his adherents. A similar tendency to cut the Gordian knot is observed in his recommendation to students faced with the very extensive literature they have to read. This is what Skinner advises: " A field of specialisation helps, but most fields are still large. Some principle of selection is needed, and a useful guide is the significance of the variables studied. A glimpse of the coordinates of the graphs in an article will usually suffice. A good rule of thumb is as follows: do not spend much time on articles in which changes in behavior are followed from trial to trial or in which graphs show changes in the time or number of errors required to reach a criterion, or in amount remembered, or in percent of correct choices made, or which report scores, raw or standard. Sometimes a look at the apparatus will help. Dimensions are probably
262
H.J.
EYSENCK
suspect if the work was done with mazes, T-mazes, jumping stanUs, or memory drums." Following these rules would certainly make life easier for the student; it would also eliminate most of the work considered important and interesting by non-Skinnerians! One of Skinner's main claims for what he insists on calling "the experimental analysis of behavior" is that "the specific method which has made it successful in the laboratory makes it almost immediately available for practical purposes. It is not concerned with testing theories but with directly modifying behavior," and he goes on to point out that "the two fields in which an experimental analysis of behavior has already yielded the most extensive technology (education and psychotherapy) are those closest to psychology itself. .... This quotation reflects two errors frequently encountered but nevertheless not presenting a true state of affairs. The technologies in question may have benefitted by the theoretical underpinning given to them by Skinner, but their inception antidates his own contribution. Teaching machines, to take but one example, were invented and developed by Pressey long before Skinner turned his interest to this field; his own contribution on the theoretical side consisted mainly in the almost certainly mistaken view that small steps of progression and almost invariable positive reinforcement were necessary and desirable ingredients in the programming of a successful teaching machine. The evidence seems to go clearly counter to this view, and, while I am willing to believe that teaching machines may in due course make a contribution to education, ! find that the evidence demonstrating their superiority over ordinary teaching methods is no better than that demonstrating the value of Freudian psychotherapy. Premature congratulations would not seem to be in order. The same may be said with respect to token economies, as applied to the rehabilitation of criminals and of chronic psychotics. This method was first advocated and put into practice by Alexander Maconochie, who was made Superintendent of the convict settlement of Norfolk Island in 1840 and later on became Governor of Birmingham Prison in England. His introduction of what he called "the mark system of prison discipline" consitutes a milestone in the field of behavior modification, and is still the best available evidence for the successful working of a token economy. To suggest that such advances are contingent upon laboratory work on operant conditioning suggests a lack of historical sophistication; it would have been very interesting to have been given Skinner's views of the work of his eminent predecessor! Skinner pays little attention to individual differences although he does not deny their existence. He simply refers them to the organism's history
CRITICAL NOTICE
263
of reinforcement. " T he complex system we call an organism has an elaborate and largely unknown history which endows it with a certain individuality"; the impressive work on genetic factors does not receive a mention, let alone a review. For Skinner, what does not interest him does not exist. This makes for a cohesive and highly motivated school, but it does not make for good scholarship or--ultimately--good science. To say this is, of course, not to deny that this volume contains much that is valuable and important. Like most people, Skinner is at his best when writing about the things that interest him, and that means, in the present context, that he is concerned with the more general problems of behavior and its control through the management of reinforcement contingencies. His discussions are pithy, often witty, and always well written: when Skinner gets away from the ugliness of operant jargon he is one of the most attractive writers in psychology. Quite often he slips in a remark which throws an entirely new light on an old topic. Consider, for instance, the following point made quite incidentally: "Recent work by Harlow and others on the behavior of infant monkeys is said to be particularly significant for human behavior because monkeys are primates; but so far as a behavioral repertoire is concerned, the human infant is much closer to a kitten or puppy than to an arboreal monkey. The kinship is not in the line of descent, but in the contingencies of survival. The monkey is more likely to survive if infants cling to their mothers, scream and run if left alone, and run to their mothers when frightened. The human baby cannot do much of this, and if it could, the behavior would have no great survival value in a species in which the mother leaves the young while foraging since highly excitable behavior in the infant would attract predators. Mild activity in hunger or physical distress and clinging and sucking when hungry are no doubt important for the human infant, but they lack the extremity of the responses of the infant monkey." This surely throws an entirely new light on Harlow's work and its relevance to human behavior. Or consider this important point which is so often forgotten by the builders of modern Utopias: "Men are happy in an environment in which active, productive, and creative behavior is reinforced in effective ways. The trouble with both affluent and welfare societies is that reinforcers are not contingent on behavior. Men who are not reinforced for doing anything do little or nothing. This is the 'contentment' of the Arcadian idyll and of the retired businessman. It may represent a satisfaction of needs, but it raises other problems. Only when we stop using reinforcers to allay the needs can we begin to use them to 'fulfill man's nature' in a much more important sense." At the other end of the scale, however, he frequently makes remarks which strike one as unlikely and rather difficult
264
H. J. E Y S E N C K
to prove. He accounts for Don Giovanni's sexual behavior in terms of a particularly effective schedule of reinforcement. "A moderate susceptibility to sexual reinforcement should be enough to make every attractive girl the occasion for attempted seduction if early successes are favorably programmed. An effective variable-ratio schedule should maintain the behavior at a high level even in a person who is sexually below normal, in which case it might be tempting to argue that the above-normal behavior shows 'compensation.'" To interpret the behavior of literary or mythological figures in terms of one's pet theory puts Skinner on the same plane as Freud or Jones, who interpreted Hamlet in terms of the Oedipus complex. This may be amusing to the literati, but it tends to take us out of science. In short, this book demonstrates one of the odd things about modem psychology, to wit, that people write well and reasonably about the things they know, and tend to talk nonsense about the things they don't know and don't care about. What is odd is not perhaps that this should be so, but rather that psychologists should ever go outside their own field of competence in this manner. A physicist working in cryogenics wouldn't dream of criticizing the methods or results of workers in cosmology, and a rheologist wouldn't consider it his job to discuss the things done by electronics experts. It is only in psychology that you tend to get this omniscience complex, this belief that only what you are doing is worth doing, and that everyone outside the narrow group is either misguided or foolish. The work that Skinner is doing is clearly important and valuable, both on the experimental and the applied level; why must he spoil a good story by implying that this is the whole of psychology, and that his methods and predilections are the only tolerable ones? This would have been a very much better book if Skinner had concentrated on the tremendous positive contribution he has made to psychology; there may be just one or two important things to be done which do not depend on the contingencies of reinforcement; and the methodology favored by Skinner, while obviously very fruitful in his hands, may with advantage be supplemented by others, in different hands and for different purposes. General verdict: brilliant but erratic; could do better with a little discipline.