problems with radical behaviorism


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(Updated 6/23/04)

Noam Chomsky
A Review of B. F. Skinner's Verbal Behavior
Language, 35, No. 1 (1959), 26-58.
"The other fundamental notion borrowed from the description of bar-pressing experiments is reinforcement. It raises problems which are similar, and even more serious. In Behavior of Organisms, "the operation of reinforcement is defined as the presentation of a certain kind of stimulus in a temporal relation with either a stimulus or response. A reinforcing stimulus is defined as such by its power to produce the resulting change [in strength]. There is no circularity about this: some stimuli are found to produce the change, others not, and they are classified as reinforcing and nonreinforcing accordingly" (62). This is a perfectly appropriate definition for the study of schedules of reinforcement. It is perfectly useless, however, in the discussion of real-life behavior, unless we can somehow characterize the stimuli which are reinforcing (and the situations and conditions under which they are reinforcing). Consider first of all the status of the basic principle that Skinner calls the "law of conditioning" (law of effect). It reads: "if the occurrence of an operant is followed by presence of a reinforcing stimulus, the strength is increased" (Behavior of Organisms, 21). As reinforcement was defined, this law becomes a tautology. For Skinner, learning is just change in response strength. Although the statement that presence of reinforcement is a sufficient condition for learning and maintenance of behavior is vacuous, the claim that it is a necessary condition may have some content, depending on how the class of reinforcers (and appropriate situations) is characterized. Skinner does make it very clear that in his view reinforcement is a necessary condition for language learning and for the continued availability of linguistic responses in the adult. However, the looseness of the term reinforcement as Skinner uses it in the book under review makes it entirely pointless to inquire into the truth or falsity of this claim. Examining the instances of what Skinner calls reinforcement, we find that not even the requirement that a reinforcer be an identifiable stimulus is taken seriously. In fact, the term is used in such a way that the assertion that reinforcement is necessary for learning and continued availability of behavior is likewise empty.

To show this, we consider some examples of reinforcement. First of all, we find a heavy appeal to automatic self-reinforcement, Thus, "a man talks to himself... because of the reinforcement he receives" (163); "the child is reinforced automatically when he duplicates the sounds of airplanes, streetcars ..." (164); "the young child alone in the nursery may automatically reinforce his own exploratory verbal behavior when he produces sounds which he has heard in the speech of others" (58); "the speaker who is also an accomplished listener 'knows when he has correctly echoed a response' and is reinforced thereby" (68); thinking is "behaving which automatically affects the behaver and is reinforcing because it does so" (438; cutting one's finger should thus be reinforcing, and an example of thinking); "the verbal fantasy, whether overt or covert, is automatically reinforcing to the speaker as listener. Just as the musician plays or composes what he is reinforced by hearing, or as the artist paints what reinforces him visually, so the speaker engaged in verbal fantasy says what he is reinforced by hearing or writes what he is reinforced by reading" (439); similarly, care in problem solving, and rationalization, are automatically self-reinforcing (442-43). We can also reinforce someone by emitting verbal behavior as such (since this rules out a class of aversive stimulations, 167), by not emitting verbal behavior (keeping silent and paying attention, 199), or by acting appropriately on some future occasion (152: "the strength of [the speaker's] behavior is determined mainly by the behavior which the listener will exhibit with respect to a given state of affairs"; this Skinner considers the general case of "communication" or "letting the listener know"). In most such cases, of course, the speaker is not present at the time when the reinforcement takes place, as when "the reinforced by the effects his works have upon... others" (224), or when the writer is reinforced by the fact that his "verbal behavior may reach over centuries or to thousands of listeners or readers at the same time. The writer may not be reinforced often or immediately, but his net reinforcement may be great" (206; this accounts for the great "strength" of his behavior). An individual may also find it reinforcing to injure someone by criticism or by bringing bad news, or to publish an experimental result which upsets the theory of a rival (154), to describe circumstances which would be reinforcing if they were to occur (165), to avoid repetition (222), to "hear" his own name though in fact it was not mentioned or to hear nonexistent words in his child's babbling (259), to clarify or otherwise intensify the effect of a stimulus which serves an important discriminative function (416), and so on.

From this sample, it can be seen that the notion of reinforcement has totally lost whatever objective meaning it may ever have had. Running through these examples, we see that a person can be reinforced though he emits no response at all, and that the reinforcing stimulus need not impinge on the reinforced person or need not even exist (it is sufficient that it be imagined or hoped for). When we read that a person plays what music he likes (165), says what he likes (165), thinks what he likes (438-39), reads what books he likes (163), etc., BECAUSE he finds it reinforcing to do so, or that we write books or inform others of facts BECAUSE we are reinforced by what we hope will be the ultimate behavior of reader or listener, we can only conclude that the term reinforcement has a purely ritual function. The phrase "X is reinforced by Y (stimulus, state of affairs, event, etc.)" is being used as a cover term for "X wants Y," "X likes Y," "X wishes that Y were the case," etc. Invoking the term reinforcement has no explanatory force, and any idea that this paraphrase introduces any new clarity or objectivity into the description of wishing, liking, etc., is a serious delusion. The only effect is to obscure the important differences among the notions being paraphrased. Once we recognize the latitude with which the term reinforcement is being used, many rather startling comments lose their initial effect -- for instance, that the behavior of the creative artist is "controlled entirely by the contingencies of reinforcement" (150). What has been hoped for from the psychologist is some indication how the casual and informal description of everyday behavior in the popular vocabulary can be explained or clarified in terms of the notions developed in careful experiment and observation, or perhaps replaced in terms of a better scheme. A mere terminological revision, in which a term borrowed from the laboratory is used with the full vagueness of the ordinary vocabulary, is of no conceivable interest." [Full Text]

MacKenzie BD.
Behaviorism and the Limits of Scientific Method.
London: RKP, 1977.

Dennett DC.
Brainstorms: Philosophical Essays in Mind and Psychology.
Hassocks, Sussex: Harvester Press, 1978.

Popper KR.
Objective Knowledge: an Evolutionary Approach.
Oxford University Press, 1972.

Stich, S.
Is Behaviorism Vacuous?
Behavioral and Brain Sciences, 7, 647-649. 1984.

Efron R.
The conditioned reflex: a meaningless concept.
Perspectives in Biology and Medicine, 1966; 9: 488-514.

N. McLaren

"As mentioned, Dennett is of the view that, at the beginning of his career, Skinner made a profound and far-reaching mistake by equating mentalism with the supernatural. The psychologist was determined to eradicate from his "science of general psychology" all mentalist concepts, and therefore never looked seriously at the age-old questions of whether a non-mentalist psychology is possible or, in the alternative, whether mentalism is genuinely beyond analysis. Thus, there was a great deal of circularity, even question-begging, in Skinner's psychology, i.e. he frequently assumed the truth of that which required proof. For example, it is typical of humans that we 'plan ahead,' which means just what everybody thinks it means. But Skinner did not allow any mentalist concepts, and planning ahead is entirely mentalist. Behavior is under the control of the environment, he believed, but since future events have not yet happened, they cannot control behavior. What appears to be a case of somebody planning ahead is, he insisted, actually a matter of their past history of reinforcing contingencies. Given a detailed account of everything that has happened to that person, we would be able to say just what compels them to act in a particular way just now such that, lo and behold, a few days or weeks down the track, they get whatever it is they said they wanted in the first place.

Unfortunately, in discarding mentalism as non-science, Skinner adopted another bit of non-science. As every psychologist knows, keeping track of the history of reinforcing contingencies of even a laboratory animal is difficult; working out what has happened to a human years before, when no records were kept, is just impossible, and all talk of doing so is fanciful. All talk of a "proper behavioral analysis" is just deus ex machina. Skinner was led to this error by his major assumptions:

1. Mentalism is necessarily supernatural;
2. Therefore, behavior must be under environmental control;
3. But future events cannot control behavior because they have not yet happened;
4. Therefore, the controlling element must lie in the past history of environmental contingencies."

"In the title to his paper, Efron asserted that the concept of the conditioned reflex was meaningless. He pointed out that, within psychology, different authors use the term 'conditioned reflex' in a variety of totally different ways. He cited the dispute between two authors, one of whom argued that worms can be 'conditioned' while the other insisted that the first did not know the difference between 'true conditioning' and 'pseudo-conditioning.' Efron made a number of points:

a) that these types of disputes were due to 'epistemological chaos' rather that to disagreements over genuine scientific facts;
b) the chaos derives from the assumption that all human behavior can be explained by reductionist materialism, i.e. that all "concepts of consciousness, volition and the causal efficacy of mental processes" can and should be excluded from the field of science;
c) that in attempting to eliminate all mention of conscious mental processes, reductionist biologists (essentially psychologists) have degraded the narrow concept of the reflex byprogressively broadening it, to the extent that it has long since become entirely meaningless;
d) all attempts to salvage a meaning for conditioning, such as operationalism, are doomed to failure because they necessarily enter an infinite regress.

Efron showed that, 150 years ago, the term 'reflex' had a very restricted meaning, essentially that of the automatic response of an intact, functioning animal to an external stimulus: "The definition of 'reflex' action contains, therefore, by implication, reference to a class or classes of action which are non-reflexive....Behavior which is automatic, innate, involuntary, and independent of consciousness needs to be isolated conceptually (i.e. defined) only because other behaviour exists which is voluntary, learned and dependent on conscious activity...To attempt to use the concept 'reflex' while at the same time denying the validity of the concepts of 'consciousness' and of 'volition' is not logically permissible" (p491). But this is exactly what reductionist psychology and biology intended to do: deny consciousness. Not explain it, nor show it was necessarily irrelevent or artefactual, but to deny the mentalism of their own minds.

The term 'reflex' was seized by late nineteenth century physiologists as part of a broad drive against the notions exemplified by Bergson's 'elan vital.' Researchers wished to dispense with the 'mysticism' inherent in such concepts as consciousness, intention, mentality, etc.. They therefore declared these notions to be non-scientific and wrote a new 'science' which did not depend on them. But in so doing, they simply replaced one form of mysticism by another, one all the more pernicious by being implicit. The neurophysiologist Karl Lashley explicated the "reductionist's credo": "Our common meeting ground is the faith to which we all subscribe...I believe, that the phenomena of behavior and mind are ultimately describable in the concepts of the mathematical and physical sciences" (quoted in Efron, p500). This particular form of mysticism is known as promissory materialism, which has been around a long time now without delivering on any of its major promises (which is, of course, just why it is called ‘promissory').

In order to eradicate mentalism, psychologists had to broaden the concept of the 'unthinking reflex,' eventually to the point where it was used to explain thought itself. Their campaign had to be managed this way. It was not possible to eliminate consciousness by reducing it to matters of brain chemistry, so they had to pursue the alternative approach, which was to squeeze consciousness out of existance by expanding the unconscious, automatic basis of behavior until it included everything that the concept of consciousness had previously encompassed. In their mechanistic world, the basic element of behavior was the reflex, but in order for it to subsume all that minds once did, it had to be redefined " such a fashion that it no longer rested upon the concept(s) of consciousness and volition" (p501). "In sum," Efron continued, "the mechanistic biologist (read: psychologist) retained the word 'reflex' because it enabled him to make implicit use of the old concept of the reflex (i.e. involuntary behavior independent of consciousness) without admitting that his 'new science of behavior' still logically rested upon the concepts of consciousness and volition. This epistemological procedure is known, in some scientific circles, as 'having your cake and eating it too'" (p501)

In Efron's view, and supported by lengthy quotes, Pavlov was one of those responsible for expanding the definition of 'reflex' to the point where it became facile. Using it, Pavlov could explain "every activity of man and beast" which, unfortunately, led directly to an infinite regress and even to self-contradiction: "By virtue of (Pavlov's) definition, it is a reflex if a hungry dog salivates in response to a bell which has in the past signaled the appearance of food; it is a reflex if I purchase a painting today which I saw and enjoyed last year; and it is a reflex if a man tries to escape from his tormentors in a concentration camp" (p506). Of course, the artist and the torturers would also be acting reflexly.

Efron's case against the conditioned reflex is unimpeachable, yet it has had remarkably little effect on behaviorist psychology. But it can be extended further. If we look at the term 'conditioned reflex' as it stands, it has no meaning. Reflex we understand (or think we do); but conditioned? What does this mean? We think it has a meaning, but only because we have heard the term so often that we accept it as real, rather in the way American psychiatrists of the fifties and sixties thought they knew what they meant by the term 'schizophrenia.' The original meaning of Pavlov's term emerges through his writings, but certainly not with any great clarity. It would appear that the salivating response his dogs showed to food was originally termed 'unconditional,' meaning one which appeared without further conditions. The food was a 'stimulus to an unconditional response' (shortened to 'unconditional stimulus') in that, without any conditions attached, it worked every time (strictly speaking, this isn't true, as Efron has argued). So an 'unconditional stimulus' leads to an 'unconditional reflex response.' The bell, however, has to be associated with the food before it can elicit any sort of response; its efficacy as a stimulus is 'conditional' upon its contiguity with the (unconditional) food stimulus. This is associationism; there is no 'process of conditioning' to be found, but the translators always used the term "conditioned reflex," implying something quite different from 'conditional reflex'. 'Conditional' is an adjective, and its meaning is quite clear, but using the word 'conditioned,' which has the form of a past participle, implies there is a verb "to condition." Today, there is such a verb in English, but its meaning is quite the same as "to associate." Skinner himself admitted this as long ago as 1931: "If we remain at the level of our observations, we must recognise a reflex as a correlation" (quoted in Efron, p498)."

Keller Breland and Marian Breland
American Psychologist, 16, 681-684. 1961.
"And if, as Hebb suggests, it is advisable to reconsider those things that behaviorism explicitly threw out, perhaps it might likewise be advisable to examine what they tacitly brought in - the hidden assumptions which led most disastrously to these breakdowns in the theory.

Three of the most important of these tacit assumptions seem to us to be: that the animal comes to the laboratory as a virtual tabula rasa, that species differences are insignificant, and that all responses are about equally conditionable to all stimuli." [Full Text]

Gary Cziko
Without Miracles: Universal Selection Theory and the Second Darwinian Revolution
"Considering now the operant conditioning of Thorndike and Skinner, we have seen how stimulus-response conceptualizations of learning cannot account for the purposeful nature of behavior as noted by William James in 1890--the ability to achieve fixed ends by varied means. Construing learning as the acquisition of fixed patterns of behavior cannot explain how organisms can be successful in achieving important goals, such as finding food, mates, and shelter, in the face of unpredictable disturbances.

Another problem with operant conditioning theory is that it provides no explanation for why certain events reinforce the organism's behavior and others do not.[19] Why is it that a hungry but well-watered rat will work a lever to obtain food but not water, while a thirsty but well-fed one will do the opposite? Perceptual control theory answers this question by seeing the reward as a controlled variable, that is, a variable that is controlled by the organism by varying its behavior. If a hungry rat pushes a lever to obtain food, it is only to bring his perceived rate of food intake close to its reference level, which has been chosen through natural selection during the evolution of the rat as a species.

Finally, perceptual control theory explains an intriguing pattern of behavior observed by Skinner that contradicts the basic notion that reinforcement increases the probability of the response preceding the reinforcing stimulus. Skinner found that he could obtain very high rates of operant conditioned behavior (such as a hungry pigeon pecking at a key to obtain food) by gradually decreasing the rate of reinforcement. Very high rates of behavior could be shaped by starting out with an easy reinforcement schedule that provided a speck of food for each key peck, and gradually moving toward more and more demanding schedules requiring more and more pecks (2, 5, 10, 50, 100) for each reward. Skinner was thereby "able to get the animals to peck thousands of times for each food pellet, over long enough periods to wear their beaks down to stubs. They would do this even though they were getting only a small fraction of the reinforcements initially obtained."[20]

But if, according to Thorndike's law of effect and Skinner's theory of operant conditioning, more reinforcement is supposed to cause more of the type of behavior that resulted in the reinforcement,[21] how could it also be that less reinforcement could also cause more of the behavior? This problem is effectively solved when we see reinforcement not as an environmental event that increases the probability of the specific behavior that preceded it, but rather as a means by which the organism can achieve a goal by controlling a perception. If the circumstances are arranged so that the hungry rat must perform more bar presses to be fed, and it has no other way to obtain food, the rat will adapt by increasing its rate of pressing to obtain its desired amount of food. And if the rate of reinforcement is increased to the point at which the rat can maintain its normal body weight, a control system model of behavior would predict that further increases in reinforcement should lead to decreases in the rate of behavior. Indeed, this is exactly what happens.[22]

It should now be obvious that a perceptual control theory interpretation of adapted behavior is radically different from a behaviorist view of operant conditioning. Whereas behaviorism sees the environment in control of the behavior of the organism, perceptual control theory sees the organism in control of its environment by means of varying its behavior. In other words, to behaviorists, behavior is controlled by the environment; to perceptual control theorists, behavior controls the environment. This is not to say that the environment has no influence on behavior. Rather, behavior can be adapted only if it is part of a larger control process that varies behavior to produce the perceptions specified by internal reference signals leading to the accomplishment of goals important for survival and reproduction." [Book Link]

Curtis Brown
Behaviorism: Skinner and Dennett
"So we can read Skinner as making the important point that when we invoke theoretical entities or phenomena we need to do so in such a way that the theory making use of them makes predictions about observable phenomena which can be falsified.

But Skinner seems to take himself to have shown something much stronger than this, namely that a scientific theory should not make use of inferred entities or phenomena at all. And this seems much too strong a claim. If we restricted physics, or even archeology or paleontology, to making use only of things that can be directly observed, we would deprive ourselves of most of their most interesting results--and also of a good deal of their predictive power. It often happens that the best theory which accounts for observed phenomena and makes predictions about unobserved but observable phenomena makes use of a good deal of theoretical apparatus for which our only evidence is inferential. An analogy may be helpful in seeing this point. Imagine typing things into the keyboard of a computer, observing the computer's responses, and trying to formulate hypotheses about how the machine will respond to various future stimuli. Conceivably we could do this without appealing to any hypotheses about how the machine is programmed, so that our theory simply took the form of correlations between inputs and outputs. But it seems quite clear that it will be far more useful to hypothesize about the machine's (internal, not directly observable) program, using hypotheses about the program together with information about inputs to formulate predictions about the machine's output. Now we may not be quite like computers, but presumably the principles which govern our behavior are at least as complex as those that govern a computer, so we may reasonably expect that formulating hypotheses about our own internal states and processes will turn out to be the most effective way of explaining and predicting our behavior. At the very least, it seems clear that it would be a mistake to rule out a priori any theory which made use of such hypotheses." [Full Text]

George Graham
Stanford Encyclopedia of Philosophy
"One defining feature of traditional behaviorism is that it tried to free psychology from having to theorize about how animals and persons represent their environment. This was important, historically, because it seemed that behavior/environment connections are a lot clearer and more manageable experimentally than internal representations. Unfortunately, for behaviorism, it's hard to imagine a more restrictive rule for psychology than a rule which prohibits hypotheses about representational storage and processing. Stich, for example, complains against Skinner that "we now have an enormous collection of experimental data which, it would seem, simply cannot be made sense of unless we postulate something like" information processing mechanisms in the heads of organisms (1998, p. 649)."

Jan De Houwer, Stefaan Vandorpe and Tom Beckers
On the role of controlled cognitive processes in human associative learning
(To appear in: A. Wills (Ed.). New directions in human associative learning. Mahwah, NJ: Lawrence Erlbaum)
"Why have associative models fared so well?
In hindsight, it seems obvious that people can learn about associations by using controlled processes such as reasoning and hypothesis testing. Why then, are associative models still dominant in modern research? One reason is that the associationistic view has a long tradition in psychology (and philosophy). It is thus difficult for many people to leave behind the associationistic view that has guided their thinking and research for many years. Another important reason is that associative models do quite well in accounting for the available empirical data. The well known Rescorla-Wagner model (Rescorla & Wagner, 1972), for instance, is compatible with a huge number of findings while being relatively simple. If our argument is correct that associative models do not provide an accurate account of the processes that underlie associative learning, how is it possible that they are able to account for so much of the data? We agree with Lovibond (2003, p. 105) that "the success of these models is due to them capturing, at least in part, the operating characteristics of the inferential learning system". What this means is that associative models (as well as probabilistic models for that matter) can be seen as (mathematical) formalisations of certain deductive reasoning processes. A system that operates on the basis of associative models does not reason, but acts very much as if it is reasoning. The associative models will thus often predict the same result as a model that is based on the assumption that humans actually generate and test hypothesis or reason in a controlled, conscious manner. The two types of models can be differentiated, however, by manipulating variables that influence the likelihood that people will reason in a certain manner but that should have no impact on the operation of the associative model. We have seen that such variables (e.g., instructions, secondary tasks, ceiling effects, nature of the cues and outcomes) do indeed have a huge effect. Given these results, it is justified to entertain the belief that participants are using controlled processes such as reasoning and to look for new ways to model and understand these processes." [.DOC file]

Andreas K. Engel, Pascal Fries & Wolf Singer
Nature Reviews Neuroscience 2, 704 -716 (2001); doi:10.1038/35094565
"Classical theories of sensory processing view the brain as a passive, stimulus-driven device. By contrast, more recent approaches emphasize the constructive nature of perception, viewing it as an active and highly selective process. Indeed, there is ample evidence that the processing of stimuli is controlled by top–down influences that strongly shape the intrinsic dynamics of thalamocortical networks and constantly create predictions about forthcoming sensory events. We discuss recent experiments indicating that such predictions might be embodied in the temporal structure of both stimulus-evoked and ongoing activity, and that synchronous oscillations are particularly important in this process. Coherence among subthreshold membrane potential fluctuations could be exploited to express selective functional relationships during states of expectancy or attention, and these dynamic patterns could allow the grouping and selection of distributed neuronal responses for further processing." [Abstract/Summary] [PDF]

Aarts H, Dijksterhuis A, De Vries P.
On the psychology of drinking: being thirsty and perceptually ready.
Br J Psychol 2001 Nov;92(Pt 4):631-42
"The present research is concerned with cognitive effects of habitually regulated primary motives. Specifically, two experiments tested the idea that feelings of thirst enhance the cognitive accessibility of, or readiness to perceive, action-relevant stimuli. In a task allegedly designed to assess mouth-detection skills, some participants were made to feel thirsty, whereas others were not. Results showed that participants who were made thirsty responded faster to drinking-related items in a lexical decision task, and performed better on an incidental recall task of drinking-related items, relative to no-thirst control participants. These results suggest that basic needs and motives, such as thirst, causes a heightened perceptual readiness to environmental cues that are instrumental in satisfying these needs." [Abstract]

Francisco Varela, Jean-Philippe Lachaux, Eugenio Rodriguez & Jacques Martinerie
Nature Reviews Neuroscience 2, 229 -239 (2001); doi:10.1038/35067550
"The emergence of a unified cognitive moment relies on the coordination of scattered mosaics of functionally specialized brain regions. Here we review the mechanisms of large-scale integration that counterbalance the distributed anatomical and functional organization of brain activity to enable the emergence of coherent behaviour and cognition. Although the mechanisms involved in large-scale integration are still largely unknown, we argue that the most plausible candidate is the formation of dynamic links mediated by synchrony over multiple frequency bands."



















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