Professor Leiber’s article for the Encyclopedia of the Social Sciences, 2nd edition (Routledge 2008):
Chomsky’s Review of B. F. Skinner’s Verbal Behavior follows
In linguistics, Noam Chomsky occupies a position like
Born in Philadelphia in 1928, Chomsky studied linguistics as a University of Pennsylvania undergraduate with Zellig Harris, a structural linguist who saw linguistics as the compact description of a community’s time-bound finite corpus of utterances (literally, sonic sequences of supposed phonetic atoms). Chomsky completed his graduate work while a Junior Fellow at Harvard (1951-54) and became a professor at MIT in 1955, rapidly advancing to a series of distinguished professorships. Syntactic Structures (1957) and Aspects of the Theory of Syntax (1965), which have made him the most cited living author, soon revolutionized linguistics.
The opening three sentences of Syntactic Structures tersely render his formalized, mentalist, and nativist view:
Syntactical investigation of a given language has as its goal the construction of a device for producing the sentences of the language under investigation… The ultimate outcome of [such] investigations should be a theory of linguistic structures in which the descriptive devices utilized in particular grammars are presented and studied abstractly… One function of this theory is to provide a general method for selecting a grammar for each language, given a corpus of this language. (Chomsky 1957 p. x).
I shall unpack each of these three sentences and follow the unpacking with some important applications.
1) Formally speaking, you cannot describe a human language by listing its sentences because there are an infinite number of them; hence, you must describe a device that would generate these and only these sentences. This “device” would display the knowledge that a competent human speaker of this language has. Language is the device, the internal brain/mind device, not the finite behavioral outputs that this device, coupled with others, produces. Linguistics is a branch of psychology. Behaviorists such as B. F. Skinner thought that knowledge of language consisted of associations between particular words (heard sound sequences). Through repetition we learn the sound sequence How are you, I would like a red apple, I am fine, but not Are you how, Red a like would I apple, Am fine I, and so on. An associative grammar like this is called finite state; it fits well with the empiricist notion that we learn everything through (sequences of) sensory experience, and it makes no use of “dubious” abstractions such as noun, pronoun, verb, auxiliary verb, adjective, etc. Yet there is massive evidence that people routinely produce new sentences that they have never heard before and have never been produced in the history of their language. Even if we limit our sentences to fifteen words or less, there are literally trillions of different but perfectly grammatical sentences of English. In fact, Chomsky gave a decisive formal proof that no human language could be generated by a finite state grammar. We simply have to internalize at least a phrase structure grammar that must make use of rules that deal in abstract categories such as noun phrase, verb phrase, noun, pronoun, verb, auxiliary verb, adjective, etc. Indeed, Chomsky proved that even a phrase structure grammar is not all we will need, nor is the surface structure of a sentence a reliable guide to its deeper features.
2) Human languages have in common many principles and processes, word forms and structures, rules and features, so what the linguist describes belongs to human language as much as to a particular language (abstracting of course from the peculiarities of particular idiolects and dialects toward humanly universal cognition). Indeed, every one of the hundreds of human language that has been described makes use of the same phrase structural concepts of noun phrase, verb phrase, pronoun, verb, adjective, etc., etc. In recent linguistics it appears that a small number of principles and initial parameter settings determine every aspect of grammar that makes a human language and differentiates it from other human languages (a good thing too, because the human baby seems equally prepared to take on any human language to which it is exposed). Chomsky has speculated that a Martian anthropologist would regard all human languages as essentially the same language.
3) “A general method for selecting a grammar for each language” given a sample corpus would also be the knowledge a human child brings to the samples of a language to which the child is exposed. A vast body of evidence about child language development has persuaded nearly all linguists and cognitive scientists that the human child is pre-programmed with a “language acquisition device.” To give an example from personal experience that is familiar to investigators of language learning, my two year old daughter, Casey, exploded into using auxiliary verbs and tag negations over the space of two weeks, saying I am going, I can’t, Susan isn’t here. All of the auxiliary verbs came in at virtually the same time and Casey tag-negated only those verbs, no others; she never said I eatn’t, I gon’t, Susan walkn’t, The cat grabn’t the bird, etc. She also said I amn’t and I am going, amn’t I. No one around Casey ever said “amn’t” but she went on happily using the construction and it wasn’t until she started school two years later that she realized no one else talked that way. Of course, Casey was doing what comes naturally. In some sense, she (or some part of her brain/mind) knew what auxiliary verbs and regular verbs were and she knew that you could tag-negate (put n’t after) auxiliaries but not other verbs. She also never said I am going, aren’t I because she knew that am is a singular verb, that are is a plural verb and that I, being a singular pronoun could not take a plural verb (are).
Now, of course, Casey had never heard the English words “noun,” “verb,” “auxiliary verb,” “tag negate,” “pronoun,” “plural,” “singular,” etc. Nonetheless, she (or some part of her brain) perfectly well knew the word kinds that these English words name, just as a monolingual speaker of Urdu knows what nouns, pronouns, and verbs are, although he may have no idea what spoken label (in Urdu or English) to use for these perfectly familiar word kinds. It is this sense of knowing, of linguistic competence, that linguistics now clearly emphasizes.
But how did Casey know about these things that no one around her ever tried to explain to her? The linguist’s answer is that hearing something is an auxiliary verb or a pronoun is just like seeing that something is a red ball or a small animal. So Casey, just like any other human child whether in a literate or tribal community, identified the different word kinds present in her environment although no one was explicitly coaching her to do this, and she recognized that auxiliary verbs but not other verbs could be tag negated, so she said “I amn’t” just as she said “I can’t” or “He isn’t” because am was an auxiliary verb and so could be tagged with n’t. Speaking and hearing a natural language is a competence acquired naturally (in the first several years of life), while reading and writing requires – unfortunately -- years of effort and explicit instruction. Similarly, our basic visual/motor competencies come to us naturally in our first years. Our recently burgeoning “cognitive sciences” attend to this central aspect of being human, our characteristic competencies or faculties that make us homo sapiens.
Chomsky maintains that his work in
linguistics, and cognitive science generally, have virtually no connection with
his political and moral views, views indeed for which he claims no expertise,
although he has published countless articles and books, interviews and
commentaries, on political and moral matters. He claims no professional
expertise in such matters because he believes that no one really has such
expertise: political and moral matters can and must be understood by all
citizens, not just by elites or would be professional apologists for elites or,
more particularly, corporate wealth and power. Chomsky rose to public attention
(and the Nixon White House’s “enemies” list) for his
opposition to the
Noam, Chomsky. Syntactic Structures.
Noam, Chomsky. Aspects of the Theory of Syntax.
A Review of
B. F. Skinner's Verbal Behavior
by Noam Chomsky
"A Review of B. F. Skinner's Verbal Behavior" in Language, 35,
No. 1 (1959), 26-58.
Preface
Preface to the 1967 reprint of
"A Review of Skinner's Verbal Behavior"
Appeared in Readings in the Psychology of Language, ed. Leon A. Jakobovits and Murray S. Miron
(Prentice-Hall, Inc., 1967), pp.142-143
by Noam Chomsky
Rereading this review after eight years, I find little of
substance that I would change if I were to write it today. I am not aware of any
theoretical or experimental work that challenges its conclusions; nor, so far
as I know, has there been any attempt to meet the criticisms that are raised in
the review or to show that they are erroneous or ill-founded.
I had intended this review not specifically as a criticism
of Skinner's speculations regarding language, but rather as a more general
critique of behaviorist (I would now prefer to say "empiricist")
speculation as to the nature of higher mental processes. My reason for discussing
Skinner's book in such detail was that it was the most careful and
thoroughgoing presentation of such speculations, an evaluation that I feel is
still accurate. Therefore, if the conclusions I attempted to substantiate in
the review are correct, as I believe they are, then
Skinner's work can be regarded as, in effect, a reductio
ad absurdum of behaviorist assumptions. My personal view is that it is a
definite merit, not a defect, of Skinner's work that it can be used for this
purpose, and it was for this reason that I tried to deal with it fairly
exhaustively. I do not see how his proposals can be improved upon, aside from
occasional details and oversights, within the framework of the general
assumptions that he accepts. I do not, in other words, see any way in which his
proposals can be substantially improved within the general framework of
behaviorist or neobehaviorist, or, more generally,
empiricist ideas that has dominated much of modern linguistics, psychology, and
philosophy. The conclusion that I hoped to establish in the review, by
discussing these speculations in their most explicit and detailed form, was
that the general point of view was largely mythology, and that its widespread
acceptance is not the result of empirical support, persuasive reasoning, or the
absence of a plausible alternative.
If I were writing today on the same topic, I would try to
make it more clear than I did that I was discussing
Skinner's proposals as a paradigm example of a futile tendency in modern
speculation about language and mind. I would also be somewhat less apologetic
and hesitant about proposing the alternative view sketched in Sections 5 and 11
-- and also less ahistorical in proposing this
alternative, since in fact it embodies assumptions that are not only plausible
and relatively well-confirmed, so it appears to me, but also deeply rooted in a
rich and largely forgotten tradition of rationalist psychology and linguistics.
I have tried to correct this imbalance in later publications (Chomsky, 1962,
1964, 1966; see also Miller et al., 1960; Katz and Postal, 1964; Fodor,
1965; Lenneberg, 1966).
I think it would also have been valuable to try to sketch
some of the reasons -- and there were many -- that have made the view I was
criticizing seem plausible over a long period, and also to discuss the reasons
for the decline of the alternative rationalist conception which, I was
suggesting, should be rehabilitated. Such a discussion would, perhaps, have
helped to place the specific critique of Skinner in a more meaningful context.
References in the Preface
Chomsky, N., "Explanatory
Models in Linguistics," in Logic, Methodology and Philosophy of Science,
ed. E. Nagel, P. Suppes, and A. Tarski.
Stanford;
----------, Current Issues in
Linguistic Theory.
----------, Cartesian Linguistics.
Fodor, J., "Could Meaning Be an 'rm'," Journal of Verbal Learning and Verbal
Behavior, 4 (1965), 73-81.
Katz, J. and P. Postal, An
Integrated Theory of Linguistic Description.
Lenneberg, E., Biological Bases of Language. (In press.)
Miller, G. A., E. Galanter,
and K. H. Pribram, Plans and the Structure of
Behavior.
1959 review:
I
A great many linguists and philosophers concerned with
language have expressed the hope that their studies might ultimately be
embedded in a framework provided by behaviorist psychology, and that refractory
areas of investigation, particularly those in which meaning is involved, will
in this way be opened up to fruitful exploration. Since this volume is the
first large-scale attempt to incorporate the major aspects of linguistic
behavior within a behaviorist framework, it merits and will undoubtedly receive
careful attention. Skinner is noted for his contributions to the study of
animal behavior. The book under review is the product of study of linguistic
behavior extending over more than twenty years. Earlier versions of it have
been fairly widely circulated, and there are quite a few references in the
psychological literature to its major ideas.
The problem to which this book is addressed is that of
giving a "functional analysis" of verbal behavior. By functional
analysis, Skinner means identification of the variables that control this
behavior and specification of how they interact to determine a particular
verbal response. Furthermore, the controlling variables are to be described
completely in terms of such notions as stimulus, reinforcement, deprivation,
which have been given a reasonably clear meaning in
animal experimentation. In other words, the goal of the book is to provide a
way to predict and control verbal behavior by observing and manipulating the
physical environment of the speaker.
Skinner feels that recent advances in the
laboratory study of animal behavior permit us to approach this problem with a
certain optimism, since "the basic processes and relations which give
verbal behavior its special characteristics are now fairly well understood ...
the results [of this experimental work] have been surprisingly free of species
restrictions. Recent work has shown that the methods can be extended to
human behavior without serious modification" (3).1
It is important to see clearly just what it is in Skinner's
program and claims that makes them appear so bold and remarkable, It is not primarily the fact that he has set functional
analysis as his problem, or that he limits himself to study of observables,
i.e., input-output relations. What is so surprising is
the particular limitations he has imposed on the way in which the observables
of behavior are to be studied, and, above all, the particularly simple nature
of the function which, he claims, describes the causation of behavior.
One would naturally expect that prediction of the behavior of a complex
organism (or machine) would require, in addition to information about external
stimulation, knowledge of the internal structure of the organism, the ways in
which it processes input information and organizes its own behavior. These
characteristics of the organism are in general a complicated product of inborn
structure, the genetically determined course of maturation, and past
experience. Insofar as independent neurophysiological
evidence is not available, it is obvious that inferences concerning the
structure of the organism are based on observation of behavior and outside
events. Nevertheless, one's estimate of the relative importance of external
factors and internal structure in the determination of behavior will have an
important effect on the direction of research on linguistic (or any other)
behavior, and on the kinds of analogies from animal behavior studies that will
be considered relevant or suggestive.
Putting it differently, anyone who sets himself the problem
of analyzing the causation of behavior will (in the absence of independent neurophysiological evidence) concern himself with the only
data available, namely the record of inputs to the organism and the organism's
present response, and will try to describe the function specifying the response
in terms of the history of inputs. This is nothing more than the definition of
his problem. There are no possible grounds for argument here, if one accepts
the problem as legitimate, though Skinner has often advanced and defended this
definition of a problem as if it were a thesis which other investigators
reject. The differences that arise between those who affirm and those who deny
the importance of the specific "contribution of the organism" to
learning and performance concern the particular character and complexity of
this function, and the kinds of observations and research necessary for
arriving at a precise specification of it. If the contribution of the organism
is complex, the only hope of predicting behavior even in a gross way will be
through a very indirect program of research that begins by studying the
detailed character of the behavior itself and the particular capacities of the
organism involved.
Skinner's thesis is that external factors consisting of
present stimulation and the history of reinforcement (in particular, the
frequency, arrangement, and withholding of reinforcing stimuli) are of
overwhelming importance, and that the general principles revealed in laboratory
studies of these phenomena provide the basis for understanding the complexities
of verbal behavior. He confidently and repeatedly voices his claim to have
demonstrated that the contribution of the speaker is quite trivial and
elementary, and that precise prediction of verbal behavior involves only
specification of the few external factors that he has isolated experimentally
with lower organisms.
Careful study of this book (and of the research on which it
draws) reveals, however, that these astonishing claims are far from justified.
It indicates, furthermore, that the insights that have been achieved in the
laboratories of the reinforcement theorist, though quite genuine, can be
applied to complex human behavior only in the most gross and superficial way,
and that speculative attempts to discuss linguistic behavior in these terms
alone omit from consideration factors of fundamental importance that are, no
doubt, amenable to scientific study, although their specific character cannot
at present be precisely formulated. Since Skinner's work is the most extensive
attempt to accommodate human behavior involving higher mental faculties within
a strict behaviorist schema of the type that has attracted many linguists and
philosophers, as well as psychologists, a detailed documentation is of
independent interest. The magnitude of the failure of this attempt to account
for verbal behavior serves as a kind of measure of the importance of the
factors omitted from consideration, and an indication of how little is really
known about this remarkably complex phenomenon.
The force of Skinner's argument lies in the enormous wealth
and range of examples for which he proposes a functional analysis. The only way
to evaluate the success of his program and the correctness of his basic
assumptions about verbal behavior is to review these examples in detail and to
determine the precise character of the concepts in terms of which the
functional analysis is presented. Section 2 of this review describes the
experimental context with respect to which these concepts are originally
defined. Sections 3 and 4 deal with the basic concepts -- stimulus, response,
and reinforcement, Sections 6 to 10 with the new descriptive machinery
developed specifically for the description of verbal behavior. In Section 5 we
consider the status of the fundamental claim, drawn from the laboratory, which
serves as the basis for the analogic guesses about
human behavior that have been proposed by many psychologists. The final section
(Section 11) will consider some ways in which further linguistic work may play
a part in clarifying some of these problems.
II
Although this book makes no direct reference to experimental
work, it can be understood only in terms of the general framework that Skinner
has developed for the description of behavior. Skinner divides the responses of
the animal into two main categories. Respondents are purely reflex
responses elicited by particular stimuli. Operants
are emitted responses, for which no obvious stimulus can be discovered. Skinner
has been concerned primarily with operant behavior. The experimental
arrangement that he introduced consists basically of a box with a bar attached
to one wall in such a way that when the bar is pressed, a food pellet is
dropped into a tray (and the bar press is recorded). A rat placed in the box
will soon press the bar, releasing a pellet into the tray. This state of
affairs, resulting from the bar press, increases the strength of the
bar-pressing operant. The food pellet is called a reinforcer;
the event, a reinforcing event. The strength of an operant is defined by
Skinner in terms of the rate of response during extinction (i.e,
after the last reinforcement and before return to the pre-conditioning rate).
Suppose that release of the pellet is
conditional on the flashing of a light. Then the rat will come to press the bar
only when the light flashes. This is called stimulus discrimination. The
response is called a discriminated operant and the light is called the occasion
for its emission: this is to be distinguished from elicitation of a response by
a stimulus in the case of the respondent.2 Suppose that the
apparatus is so arranged that bar-pressing of only a certain character (e.g.,
duration) will release the pellet. The rat will then come to press the bar in
the required way. This process is called response differentiation. By
successive slight changes in the conditions under which the response will be
reinforced, it is possible to shape the response of a rat or a pigeon in very
surprising ways in a very short time, so that rather complex behavior can be
produced by a process of successive approximation.
A stimulus can become reinforcing by repeated
association with an already reinforcing stimulus. Such a stimulus is called a secondary
reinforcer. Like many contemporary behaviorists, Skinner
considers money, approval, and the like to be secondary reinforcers
which have become reinforcing because of their association with food, etc.3
Secondary reinforcers can be generalized by
associating them with a variety of different primary reinforcers.
Another variable that can affect the rate of the
bar-pressing operant is drive, which Skinner defines operationally in
terms of hours of deprivation. His major scientific book, Behavior of
Organisms, is a study of the effects of food-deprivation and conditioning
on the strength of the bar-pressing response of healthy mature rats. Probably Skinner's most original contribution to animal behavior
studies has been his investigation of the effects of intermittent
reinforcement, arranged in various different ways, presented in Behavior of
Organisms and extended (with pecking of pigeons as the operant under
investigation) in the recent Schedules of Reinforcement by Ferster and Skinner (1957). It is apparently these studies
that Skinner has in mind when he refers to the recent advances in the study of
animal behavior.4
The notions stimulus, response, reinforcement
are relatively well defined with respect to the bar-pressing experiments and
others similarly restricted. Before we can extend them to real-life behavior,
however, certain difficulties must be faced. We must decide, first of all,
whether any physical event to which the organism is capable of reacting is to
be called a stimulus on a given occasion, or only one to which the organism in
fact reacts; and correspondingly, we must decide whether any part of behavior
is to be called a response, or only one connected with stimuli in lawful ways.
Questions of this sort pose something of a dilemma for the experimental
psychologist. If he accepts the broad definitions, characterizing any physical
event impinging on the organism as a stimulus and any part of the organism's
behavior as a response, he must conclude that behavior has not been
demonstrated to be lawful. In the present state of our knowledge, we must
attribute an overwhelming influence on actual behavior to ill-defined factors
of attention, set, volition, and caprice. If we accept the narrower
definitions, then behavior is lawful by definition (if it consists of
responses); but this fact is of limited significance, since most of what the
animal does will simply not be considered behavior. Hence, the psychologist
either must admit that behavior is not lawful (or that he cannot at present
show that it is -- not at all a damaging admission for a developing science),
or must restrict his attention to those highly limited areas in which it is
lawful (e.g., with adequate controls, bar-pressing in rats; lawfulness of the
observed behavior provides, for Skinner, an implicit definition of a good
experiment).
Skinner does not consistently adopt either course. He
utilizes the experimental results as evidence for the scientific character of
his system of behavior, and analogic guesses (formulated
in terms of a metaphoric extension of the technical vocabulary of the
laboratory) as evidence for its scope. This creates the illusion of a rigorous
scientific theory with a very broad scope, although in fact the terms used in
the description of real-life and of laboratory behavior may be mere homonyms,
with at most a vague similarity of meaning. To substantiate this
evaluation, a critical account of his book must show that with a literal
reading (where the terms of the descriptive system have something like the
technical meanings given in Skinner's definitions) the book covers almost no
aspect of linguistic behavior, and that with a metaphoric reading, it is no
more scientific than the traditional approaches to this subject matter, and
rarely as clear and careful.5
III
Consider first Skinner's use of the notions stimulus
and response. In Behavior of Organisms (9) he commits himself to
the narrow definitions for these terms. A part of the environment and a part of
behavior are called stimulus (eliciting, discriminated, or reinforcing)
and response, respectively, only if they are lawfully related; that is,
if the dynamic laws relating them show smooth and reproducible curves. Evidently, stimuli and responses, so defined, have not been shown to
figure very widely in ordinary human behavior.6 We can, in the face of
presently available evidence, continue to maintain the lawfulness of the
relation between stimulus and response only by depriving them of their
objective character. A typical example of stimulus control for Skinner
would be the response to a piece of music with the utterance Mozart or
to a painting with the response Dutch. These responses are asserted to
be "under the control of extremely subtle properties" of the physical
object or event (108). Suppose instead of saying Dutch we had said Clashes
with the wallpaper, I thought you liked abstract work, Never saw it before,
Tilted, Hanging too low, Beautiful, Hideous, Remember our camping trip last
summer?, or whatever else might come into our minds when looking at a
picture (in Skinnerian translation, whatever other responses exist in
sufficient strength). Skinner could only say that each of these responses is
under the control of some other stimulus property of the physical object. If we
look at a red chair and say red, the response is under the control of
the stimulus redness; if we say chair, it is under the control of
the collection of properties (for Skinner, the object) chairness
(110), and similarly for any other response. This device is as simple as it is
empty. Since properties are free for the asking (we have as many of them as we
have nonsynonymous descriptive expressions in our
language, whatever this means exactly), we can account for a wide class of
responses in terms of Skinnerian functional analysis by identifying the controlling
stimuli. But the word stimulus has lost all objectivity in this usage.
Stimuli are no longer part of the outside physical world; they are driven back
into the organism. We identify the stimulus when we hear the response. It is
clear from such examples, which abound, that the talk of stimulus control
simply disguises a complete retreat to mentalistic
psychology. We cannot predict verbal behavior in terms of the stimuli in the
speaker's environment, since we do not know what the current stimuli are until
he responds. Furthermore, since we cannot control the property of a
physical object to which an individual will respond, except in highly
artificial cases, Skinner's claim that his system, as opposed to the
traditional one, permits the practical control of verbal behavior7 is quite false.
Other examples of stimulus control merely add to the
general mystification. Thus, a proper noun is held to be a response "under
the control of a specific person or thing" (as controlling stimulus, 113).
I have often used the words Eisenhower and
A multitude of similar questions arise immediately. It
appears that the word control here is merely a misleading paraphrase for
the traditional denote or refer. The assertion (115) that so far
as the speaker is concerned, the relation of reference is "simply the
probability that the speaker will emit a response of a given form in the
presence of a stimulus having specified properties" is surely incorrect if
we take the words presence, stimulus, and probability in
their literal sense. That they are not intended to be taken literally is
indicated by many examples, as when a response is said to be
"controlled" by a situation or state of affairs as
"stimulus." Thus, the expression a needle in a haystack
"may be controlled as a unit by a particular type of situation"
(116); the words in a single part of speech, e.g., all adjectives, are under
the control of a single set of subtle properties of stimuli (121); "the
sentence The boy runs a store is under the control of an extremely
complex stimulus situation" (335) "He is not at all well may
function as a standard response under the control of a state of affairs which
might also control He is ailing" (325); when an envoy observes
events in a foreign country and reports upon his return, his report is under
"remote stimulus control" (416); the statement This is war may
be a response to a "confusing international situation" (441); the
suffix -ed is controlled by that "subtle property of stimuli which
we speak of as action-in-the-past" (121) just as the -s in The
boy runs is under the control of such specific features of the situation as
its "currency" (332). No characterization of the notion stimulus
control that is remotely related to the bar-pressing experiment (or that
preserves the faintest objectivity) can be made to cover a set of examples like
these, in which, for example, the controlling stimulus need not even impinge on
the responding organism.
Consider now Skinner's use of the notion response.
The problem of identifying units in verbal behavior has of course been a
primary concern of linguists, and it seems very likely that experimental psychologists
should be able to provide much-needed assistance in clearing up the many
remaining difficulties in systematic identification. Skinner recognizes (20)
the fundamental character of the problem of identification of a unit of verbal
behavior, but is satisfied with an answer so vague and subjective that it does
not really contribute to its solution. The unit of verbal behavior -- the
verbal operant -- is defined as a class of responses of identifiable form
functionally related to one or more controlling variables. No method is
suggested for determining in a particular instance what are the controlling
variables, how many such units have occurred, or where their boundaries are in
the total response. Nor is any attempt made to specify how much or what kind of
similarity in form or control is required for two physical events to be
considered instances of the same operant. In short, no answers are suggested
for the most elementary questions that must be asked of anyone proposing a
method for description of behavior. Skinner is content with what he calls an extrapolation
of the concept of operant developed in the laboratory to the verbal field. In
the typical Skinnerian experiment, the problem of identifying the unit of
behavior is not too crucial. It is defined, by fiat, as a recorded peck or
bar-press, and systematic variations in the rate of this operant and its
resistance to extinction are studied as a function of deprivation and
scheduling of reinforcement (pellets). The operant is thus defined with respect
to a particular experimental procedure. This is perfectly reasonable and has
led to many interesting results. It is, however, completely meaningless to
speak of extrapolating this concept of operant to ordinary verbal behavior.
Such "extrapolation" leaves us with no way of justifying one or
another decision about the units in the "verbal repertoire."
Skinner specifies "response
strength" as the basic datum, the basic dependent variable in his
functional analysis. In the bar-pressing experiment, response strength is
defined in terms of rate of emission during extinction. Skinner has argued8
that this is "the only datum that varies significantly and in the expected
direction under conditions which are relevant to the 'learning process.'"
In the book under review, response strength is defined as "probability of
emission" (22). This definition provides a comforting impression of
objectivity, which, however, is quickly dispelled when we look into the matter
more closely. The term probability has some rather obscure
meaning for Skinner in this book.9 We are told, on the
one hand, that "our evidence for the contribution of each variable [to
response strength] is based on observation of frequencies alone" (28). At
the same time, it appears that frequency is a very misleading measure of
strength, since, for example, the frequency of a response may be
"primarily attributable to the frequency of occurrence of controlling
variables" (27). It is not clear how the frequency of a response can be
attributable to anything BUT the frequency of occurrence of its controlling
variables if we accept Skinner's view that the behavior occurring in a given
situation is "fully determined" by the relevant controlling variables
(175, 228). Furthermore, although the evidence for the contribution of each
variable to response strength is based on observation of frequencies alone, it
turns out that "we base the notion of strength upon several kinds of
evidence" (22), in particular (22-28): emission of the response
(particularly in unusual circumstances), energy level (stress), pitch level,
speed and delay of emission, size of letters etc. in writing, immediate repetition,
and -- a final factor, relevant but misleading -- over-all frequency.
Of course, Skinner recognizes that these
measures do not co-vary, because (among other reasons) pitch, stress, quantity,
and reduplication may have internal linguistic functions.10
However, he does not hold these conflicts to be very important, since the
proposed factors indicative of strength are "fully understood by
everyone" in the culture (27). For example, "if we are shown a prized
work of art and exclaim Beautiful!, the speed and energy of the response will not be
lost on the owner." It does not appear totally obvious that in this case
the way to impress the owner is to shriek Beautiful in a loud, high-pitched
voice, repeatedly, and with no delay (high response strength). It may be
equally effective to look at the picture silently (long delay) and then to
murmur Beautiful in a soft, low-pitched voice (by definition, very low
response strength).
It is not unfair, I believe, to conclude from Skinner's
discussion of response strength, the basic datum in functional analysis,
that his extrapolation of the notion of probability can best be
interpreted as, in effect, nothing more than a decision to use the word probability,
with its favorable connotations of objectivity, as a cover term to paraphrase
such low-status words as interest, intention, belief, and
the like. This interpretation is fully justified by the way in which Skinner
uses the terms probability and strength. To cite just one
example, Skinner defines the process of confirming an assertion in science as
one of "generating additional variables to increase its probability"
(425), and more generally, its strength (425-29). If we take this suggestion quite
literally, the degree of confirmation of a scientific assertion can be measured
as a simple function of the loudness, pitch, and frequency with which it is
proclaimed, and a general procedure for increasing its degree of confirmation
would be, for instance, to train machine guns on large crowds of people who
have been instructed to shout it. A better indication of what Skinner probably
has in mind here is given by his description of how the theory of evolution, as
an example, is confirmed. This "single set of verbal responses ... is made
more plausible -- is strengthened -- by several types of construction based
upon verbal responses in geology, paleontology, genetics, and so on"
(427). We are no doubt to interpret the terms strength and probability
in this context as paraphrases of more familiar locutions such as
"justified belief" or "warranted assertability," or something of the sort. Similar latitude of interpretation is
presumably expected when we read that "frequency of effective action
accounts in turn for what we may call the listener's 'belief'" (88) or
that "our belief in what someone tells us is similarly a function of, or
identical with, our tendency to act upon the verbal stimuli which he
provides" (160).11
I think it is evident, then, that Skinner's use of the
terms stimulus, control, response, and strength
justify the general conclusion stated in the last paragraph of Section 2. The
way in which these terms are brought to bear on the actual data indicates that
we must interpret them as mere paraphrases for the popular vocabulary commonly
used to describe behavior and as having no particular connection with the
homonymous expressions used in the description of laboratory experiments.
Naturally, this terminological revision adds no objectivity to the familiar mentalistic mode of description.
IV
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 definition12 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.13 For
Skinner, learning is just change in response strength.14 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.15 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 artist...is 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.
It seems that Skinner's claim that all
verbal behavior is acquired and maintained in "strength" through
reinforcement is quite empty, because his notion of reinforcement has no clear
content, functioning only as a cover term for any factor, detectable or not,
related to acquisition or maintenance of verbal behavior.16
Skinner's use of the term conditioning suffers from a similar
difficulty. Pavlovian and operant conditioning are
processes about which psychologists have developed real understanding.
Instruction of human beings is not. The claim that instruction and imparting of
information are simply matters of conditioning (357-66) is pointless. The claim
is true, if we extend the term conditioning to cover these processes,
but we know no more about them after having revised this term in such a way as
to deprive it of its relatively clear and objective character. It is, as far as
we know, quite false, if we use conditioning in its literal sense.
Similarly, when we say that "it is the function of predication to facilitate
the transfer of response from one term to another or from one object to
another" (361), we have said nothing of any significance. In what sense is
this true of the predication Whales are mammals? Or, to take Skinner's
example, what point is there in saying that the effect of The telephone is
out of order on the listener is to bring behavior formerly controlled by
the stimulus out of order under control of the stimulus telephone
(or the telephone itself) by a process of simple conditioning (362)? What laws
of conditioning hold in this case? Furthermore, what behavior is controlled by
the stimulus out of order, in the abstract? Depending on the object of
which this is predicated, the present state of motivation of the listener,
etc., the behavior may vary from rage to pleasure, from fixing the object to
throwing it out, from simply not using it to trying to use it in the normal way
(e.g., to see if it is really out of order), and so on. To speak of
"conditioning" or "bringing previously available behavior under
control of a new stimulus" in such a case is just a kind of play-acting at
science (cf. also 43n).
V
The claim that careful arrangement of
contingencies of reinforcement by the verbal community is a necessary condition
for language-learning has appeared, in one form or another, in many places.17
Since it is based not on actual observation, but on analogies to laboratory
study of lower organisms, it is important to determine the status of the
underlying assertion within experimental psychology proper. The most common
characterization of reinforcement (one which Skinner explicitly rejects,
incidentally) is in terms of drive reduction. This characterization can be
given substance by defining drives in some way independently of what in fact is
learned. If a drive is postulated on the basis of the fact that learning takes
place, the claim that reinforcement is necessary for learning will again become
as empty as it is in the Skinnerian framework. There is an extensive literature
on the question of whether there can be learning without drive reduction
(latent learning). The "classical" experiment of Blodgett
indicated that rats who had explored a maze without reward showed a marked drop
in number of errors (as compared to a control group which had not explored the
maze) upon introduction of a food reward, indicating that the rat had learned
the structure of the maze without reduction of the hunger drive.
Drive-reduction theorists countered with an exploratory drive which was reduced
during the pre-reward learning, and claimed that a slight decrement in errors
could be noted before food reward. A wide variety of experiments, with somewhat
conflicting results, have been carried out with a similar design.18 Few
investigators still doubt the existence of the phenomenon, E. R. Hilgard, in his general review of learning theory,19 concludes that
"there is no longer any doubt but that, under appropriate circumstances,
latent learning is demonstrable."
More recent work has shown that novelty and
variety of stimulus are sufficient to arouse curiosity in the rat and to
motivate it to explore (visually), and in fact, to learn (since on a
presentation of two stimuli, one novel, one repeated, the rat will attend to
the novel one),20 that
rats will learn to choose the arm of a single-choice maze that leads to a
complex maze, running through this being their only "reward";21 that
monkeys can learn object discriminations and maintain their performance at a
high level of efficiency with visual exploration (looking out of a window for
30 seconds) as the only reward22 and,
perhaps most strikingly of all, that monkeys and apes will solve rather complex
manipulation problems that are simply placed in their cages, and will solve
discrimination problems with only exploration and manipulation as incentives.23 In
these cases, solving the problem is apparently its own "reward."
Results of this kind can be handled by reinforcement theorists only if they are
willing to set up curiosity, exploration, and manipulation drives, or to
speculate somehow about acquired drives24 for which there is
no evidence outside of the fact that learning takes place in these cases.
There is a variety of other kinds of
evidence that has been offered to challenge the view that drive reduction is
necessary for learning. Results on sensory-sensory conditioning have been
interpreted as demonstrating learning without drive reduction.25
Olds has reported reinforcement by direct stimulation of the brain,
from which he concludes that reward need not satisfy a physiological need or
withdraw a drive stimulus.26 The
phenomenon of imprinting, long observed by zoologists, is of particular
interest in this connection. Some of the most complex patterns of behavior of
birds, in particular, are directed towards objects and animals of the type to
which they have been exposed at certain critical early periods of life.27 Imprinting is the
most striking evidence for the innate disposition of the animal to learn in a
certain direction and to react appropriately to patterns and objects of certain
restricted types, often only long after the original learning has taken place.
It is, consequently, unrewarded learning, though the
resulting patterns of behavior may be refined through reinforcement. Acquisition of the typical songs of song birds is, in some cases, a
type of imprinting. Thorpe reports studies that show "that some
characteristics of the normal song have been learned in the earliest youth,
before the bird itself is able to produce any kind of full song."28 The
phenomenon of imprinting has recently been investigated under laboratory
conditions and controls with positive results.29
Phenomena of this general type are certainly familiar from
everyday experience. We recognize people and places to which we have given no
particular attention. We can look up something in a book and learn it perfectly
well with no other motive than to confute reinforcement theory, or out of
boredom, or idle curiosity. Everyone engaged in research must have had the
experience of working with feverish and prolonged intensity to write a paper
which no one else will read or to solve a problem which no one else thinks
important and which will bring no conceivable reward -- which may only confirm
a general opinion that the researcher is wasting his time on irrelevancies. The
fact that rats and monkeys do likewise is interesting and important to show in
careful experiment. In fact, studies of behavior of the type mentioned above
have an independent and positive significance that far outweighs their
incidental importance in bringing into question the claim that learning is
impossible without drive reduction. It is not at all unlikely that insights
arising from animal behavior studies with this broadened scope may have the
kind of relevance to such complex activities as verbal behavior that
reinforcement theory has, so far, failed to exhibit. In any event, in the light
of presently available evidence, it is difficult to see how anyone can be
willing to claim that reinforcement is necessary for learning, if reinforcement
is taken seriously as something identifiable independently of the resulting
change in behavior.
Similarly, it seems quite beyond question
that children acquire a good deal of their verbal and nonverbal behavior by
casual observation and imitation of adults and other children.30
It is simply not true that children can learn language only through
"meticulous care" on the part of adults who shape their verbal
repertoire through careful differential reinforcement, though it may be that
such care is often the custom in academic families. It is a common observation
that a young child of immigrant parents may learn a second language in the
streets, from other children, with amazing rapidity, and that his speech may be
completely fluent and correct to the last allophone, while the subtleties that
become second nature to the child may elude his parents despite high motivation
and continued practice. A child may pick up a large part of his vocabulary and
"feel" for sentence structure from television, from reading, from
listening to adults, etc. Even a very young child who has not yet acquired a minimal
repertoire from which to form new utterances may imitate a word quite well on
an early try, with no attempt on the part of his parents to teach it to him. It
is also perfectly obvious that, at a later stage, a child will be able to
construct and understand utterances which are quite new, and are, at the same
time, acceptable sentences in his language. Every time an adult reads a
newspaper, he undoubtedly comes upon countless new sentences which are not at
all similar, in a simple, physical sense, to any that he has heard before, and
which he will recognize as sentences and understand; he will also be able to
detect slight distortions or misprints. Talk of "stimulus
generalization" in such a case simply perpetuates the mystery under a new
title. These abilities indicate that there must be fundamental processes at
work quite independently of "feedback" from the environment. I have
been able to find no support whatsoever for the doctrine of Skinner and others that slow and careful shaping of verbal behavior through
differential reinforcement is an absolute necessity. If reinforcement theory
really requires the assumption that there be such
meticulous care, it seems best to regard this simply as a reductio
ad absurdum argument against this approach. It is also not easy to find any
basis (or, for that matter, to attach very much content) to the claim that
reinforcing contingencies set up by the verbal community are the single factor
responsible for maintaining the strength of verbal behavior. The sources of the
"strength" of this behavior are almost a total mystery at present.
Reinforcement undoubtedly plays a significant role, but so do a variety of
motivational factors about which nothing serious is known in the case of human
beings.
As far as acquisition of language is concerned, it seems
clear that reinforcement, casual observation, and natural inquisitiveness
(coupled with a strong tendency to imitate) are important factors, as is the
remarkable capacity of the child to generalize, hypothesize, and "process
information" in a variety of very special and apparently highly complex
ways which we cannot yet describe or begin to understand, and which may be
largely innate, or may develop through some sort of learning or through
maturation of the nervous system. The manner in which such factors operate and
interact in language acquisition is completely unknown. It is clear that what
is necessary in such a case is research, not dogmatic and perfectly arbitrary
claims, based on analogies to that small part of the experimental literature in
which one happens to be interested.
The pointlessness of these claims becomes
clear when we consider the well-known difficulties in determining to what
extent inborn structure, maturation, and learning are responsible for the particular
form of a skilled or complex performance.31 To take
just one example,32 the gaping response
of a nestling thrush is at first released by jarring of the nest, and, at a
later stage, by a moving object of specific size, shape, and position relative
to the nestling. At this later stage the response is directed toward the part
of the stimulus object corresponding to the parent's head, and characterized by
a complex configuration of stimuli that can be precisely described. Knowing
just this, it would be possible to construct a speculative, learning-theoretic
account of how this sequence of behavior patterns might have developed through
a process of differential reinforcement, and it would no doubt be possible to
train rats to do something similar. However, there appears to be good evidence
that these responses to fairly complex "sign stimuli" are genetically
determined and mature without learning. Clearly, the possibility cannot be
discounted. Consider now the comparable case of a child imitating new words. At
an early stage we may find rather gross correspondences. At a later stage, we
find that repetition is of course far from exact (i.e., it is not mimicry, a
fact which itself is interesting), but that it reproduces the highly complex
configuration of sound features that constitute the phonological structure of
the language in question. Again, we can propose a speculative account of how
this result might have been obtained through elaborate arrangement of
reinforcing contingencies. Here too, however, it is possible that ability to
select out of the complex auditory input those features that are phonologically
relevant may develop largely independently of reinforcement, through
genetically determined maturation. To the extent that this is true, an account
of the development and causation of behavior that fails to consider the
structure of the organism will provide no understanding of the real processes
involved.
It is often argued that experience, rather than innate
capacity to handle information in certain specific ways, must be the factor of
overwhelming dominance in determining the specific character of language
acquisition, since a child speaks the language of the group in which he lives.
But this is a superficial argument. As long as we are speculating, we may
consider the possibility that the brain has evolved to the point where, given
an input of observed Chinese sentences, it produces (by an induction of
apparently fantastic complexity and suddenness) the rules of Chinese
grammar, and given an input of observed English sentences, it produces (by,
perhaps, exactly the same process of induction) the rules of English grammar;
or that given an observed application of a term to certain instances, it
automatically predicts the extension to a class of complexly related instances.
If clearly recognized as such, this speculation is neither unreasonable nor
fantastic; nor, for that matter, is it beyond the bounds of possible study. There is of course no known neural structure capable of performing
this task in the specific ways that observation of the resulting behavior might
lead us to postulate; but for that matter, the structures capable of accounting
for even the simplest kinds of learning have similarly defied detection.33 Summarizing this
brief discussion, it seems that there is neither empirical evidence nor any
known argument to support any specific claim about the relative importance of
"feedback" from the environment and the "independent
contribution of the organism" in the process of language acquisition.
VI
We now turn to the system that Skinner develops
specifically for the description of verbal behavior. Since this system is based
on the notions stimulus, response, and reinforcement, we
can conclude from the preceding sections that it will be vague and arbitrary.
For reasons noted in Section 1, however, I think it is important to see in
detail how far from the mark any analysis phrased solely in these terms must be
and how completely this system fails to account for the facts of verbal
behavior. Consider first the term verbal behavior itself. This is
defined as "behavior reinforced through the mediation of other
persons" (2). The definition is clearly much too broad. It would include
as verbal behavior, for example, a rat pressing the bar in a Skinner-box, a
child brushing his teeth, a boxer retreating before an opponent, and a mechanic
repairing an automobile. Exactly how much of ordinary linguistic behavior is verbal
in this sense, however, is something of a question: perhaps, as I have pointed
out above, a fairly small fraction of it, if any substantive meaning is
assigned to the term reinforced. This definition is subsequently refined
by the additional provision that the mediating response of the reinforcing
person (the listener) must itself "have been conditioned precisely
in order to reinforce the behavior of the speaker" (225, italics his).
This still covers the examples given above, if we can assume that the
reinforcing behavior of the psychologist, the parent, the opposing boxer, and
the paying customer are the result of appropriate training, which is perhaps
not unreasonable. A significant part of the fragment of linguistic behavior
covered by the earlier definition will no doubt be excluded by the refinement,
however. Suppose, for example, that while crossing the street I hear someone
shout Watch out for the car and jump out of the way. It can hardly be
proposed that my jumping (the mediating, reinforcing response in Skinner's
usage) was conditioned (that is, I was trained to jump) precisely in order to
reinforce the behavior of the speaker; and similarly, for a wide class of
cases. Skinner's assertion that with this refined definition
"we narrow our subject to what is traditionally recognized as the verbal
field" (225) appears to be grossly in error.
VII
Verbal operants are classified by
Skinner in terms of their "functional" relation to discriminated
stimulus, reinforcement, and other verbal responses. A mand
is defined as "a verbal operant in which the response is reinforced by a
characteristic consequence and is therefore under the functional control of
relevant conditions of deprivation or aversive stimulation" (35). This is
meant to include questions, commands, etc. Each of the terms in this definition
raises a host of problems. A mand such as Pass the
salt is a class of responses. We cannot tell by observing the form of a
response whether it belongs to this class (Skinner is very clear about this),
but only by identifying the controlling variables. This is generally
impossible. Deprivation is defined in the bar-pressing experiment in terms of
length of time that the animal has not been fed or permitted to drink. In the
present context, however, it is quite a mysterious notion. No attempt is made
here to describe a method for determining "relevant conditions of
deprivation" independently of the "controlled" response. It is
of no help at all to be told (32) that it can be characterized in terms of the
operations of the experimenter. If we define deprivation in terms
of elapsed time, then at any moment a person is in countless states of
deprivation.34
It appears that we must decide that the relevant condition of deprivation was
(say) salt-deprivation, on the basis of the fact that the speaker asked for
salt (the reinforcing community which "sets up" the mand is in a similar predicament). In this case, the
assertion that a mand is under the control of
relevant deprivation is empty, and we are (contrary to Skinner's intention)
identifying the response as a mand completely in
terms of form. The word relevant in the definition above conceals some
rather serious complications.
In the case of the
The notion aversive control is just as confused.
This is intended to cover threats, beating, and the like (33). The manner in
which aversive stimulation functions is simply described. If a speaker has had
a history of appropriate reinforcement (e.g., if a certain response was
followed by "cessation of the threat of such injury -- of events which
have previously been followed by such injury and which are therefore
conditioned aversive stimuli"), then he will tend to give the proper
response when the threat which had previously been followed by the injury is
presented. It would appear to follow from this description that a speaker will
not respond properly to the mand Your
money or your life (38) unless he has a past history of being killed. But
even if the difficulties in describing the mechanism of aversive control are
somehow removed by a more careful analysis, it will be of little use for
identifying operants for reasons similar to those
mentioned in the case of deprivation.
It seems, then, that in Skinner's terms there is in most
cases no way to decide whether a given response is an instance of a particular mand. Hence it is meaningless, within the terms of his
system, to speak of the characteristic consequences of a mand, as in the definition above. Furthermore, even if we
extend the system so that mands can somehow be
identified, we will have to face the obvious fact that most of us are not
fortunate enough to have our requests, commands, advice,
and so on characteristically reinforced (they may nevertheless exist in
considerable strength). These responses could therefore not be
considered mands by Skinner. In fact, Skinner sets up
a category of "magical mands" (48-49) to
cover the case of "mands which cannot be
accounted for by showing that they have ever had the effect specified or any
similar effect upon similar occasions" (the word ever in this
statement should be replaced by characteristically). In these pseudo-mands, "the speaker simply describes the reinforcement
appropriate to a given state of deprivation or aversive stimulation." In
other words, given the meaning that we have been led to assign to reinforcement
and deprivation, the speaker asks for what he wants. The remark that
"a speaker appears to create new mands on the
analogy of old ones" is also not very helpful.
Skinner's claim that his new descriptive system is superior
to the traditional one "because its terms can be defined with respect to
experimental operations" (45) is, we see once again, an illusion. The
statement "X wants Y" is not clarified by pointing out a relation
between rate of bar-pressing and hours of food-deprivation; replacing "X
wants Y" by "X is deprived of Y" adds no new objectivity to the
description of behavior. His further claim for the superiority of the new
analysis of mands is that it provides an objective
basis for the traditional classification into requests, commands, etc. (38-41).
The traditional classification is in terms of the intention of the speaker. But
intention, Skinner holds, can be reduced to contingencies of reinforcement,
and, correspondingly, we can explain the traditional classification in terms of
the reinforcing behavior of the listener. Thus, a question is a mand which "specifies verbal action,
and the behavior of the listener permits us to classify it as a request, a
command, or a prayer" (39). It is a request if "the listener is
independently motivated to reinforce the speaker" a command if "the
listener's behavior is... reinforced by reducing a threat, a prayer if the mand "promotes reinforcement by generating an
emotional disposition." The mand is advice if
the listener is positively reinforced by the consequences of mediating the
reinforcement of the speaker; it is a warning if "by carrying out the
behavior specified by the speaker, the listener escapes from aversive
stimulation" and so on. All this is obviously wrong if Skinner is using
the words request, command, etc., in anything like the sense of
the corresponding English words. The word question does not cover
commands. Please pass the salt is a request (but not a question),
whether or not the listener happens to be motivated to fulfill it; not everyone
to whom a request is addressed is favorably disposed. A response does not cease
to be a command if it is not followed; nor does a question become a command if
the speaker answers it because of an implied or imagined threat. Not all advice
is good advice, and a response does not cease to be advice if it is not
followed. Similarly, a warning may be misguided; heeding it may cause aversive
stimulation, and ignoring it might be positively reinforcing. In short, the
entire classification is beside the point. A moment's thought is sufficient to
demonstrate the impossibility of distinguishing between requests, commands,
advice, etc., on the basis of the behavior or disposition of the particular
listener. Nor can we do this on the basis of the typical behavior of all
listeners. Some advice is never taken, is always bad, etc., and similarly, with
other kinds of mands. Skinner's evident satisfaction
with this analysis of the traditional classification is extremely puzzling.
VIII
Mands are operants with no specified
relation to a prior stimulus. A tact, on the other hand, is defined as
"a verbal operant in which a response of given form is evoked (or at least
strengthened) by a particular object or event or property of an object or
event" (81). The examples quoted in the discussion of stimulus control
(Section 3) are all tacts. The obscurity of the
notion stimulus control makes the concept of the tact rather mystical.
Since, however, the tact is "the most important of verbal operants," it is important to investigate the
development of this concept in more detail.
We first ask why the verbal community "sets up" tacts in the child -- that is, how the parent is reinforced
by setting up the tact. The basic explanation for this behavior of the parent
(85-86) is the reinforcement he obtains by the fact that his contact with the
environment is extended; to use Skinner's example, the child may later be able
to call him to the telephone. (It is difficult to see, then, how first children
acquire tacts, since the parent does not have the
appropriate history of reinforcement.) Reasoning in the same way, we may
conclude that the parent induces the child to walk so that he can make some
money delivering newspapers. Similarly, the parent sets up an "echoic
repertoire" (e.g., a phonemic system) in the child because this makes it
easier to teach him new vocabulary, and extending the
child's vocabulary is ultimately useful to the parent. "In
all these cases we explain the behavior of the reinforcing listener by pointing
to an improvement in the possibility of controlling the speaker whom he
reinforces" (56). Perhaps this provides the explanation for the
behavior of the parent in inducing the child to walk: the parent is reinforced
by the improvement in his control of the child when the child's mobility
increases. Underlying these modes of explanation is a curious view that it is somehow
more scientific to attribute to a parent a desire to control the child or
enhance his own possibilities for action than a desire to see the child develop
and extend his capacities. Needless to say, no evidence is offered to support
this contention.
Consider now the problem of explaining the response of the
listener to a tact. Suppose, for example, that B hears
A say fox and reacts appropriately -- looks
around, runs away, aims his rifle, etc. How can we explain B's behavior? Skinner rightly rejects analyses of this offered by J. B. Watson and
Bertrand Russell. His own equally inadequate analysis proceeds as follows
(87-88). We assume (l) "that in the history of [B] the stimulus fox
has been an occasion upon which looking around has been followed by seeing a
fox" and (2) "that the listener has some current 'interest in seeing
foxes' -- that behavior which depends upon a seen fox for its execution is
strong, and that the stimulus supplied by a fox is therefore reinforcing."
B carries out the appropriate behavior, then, because "the heard stimulus fox
is the occasion upon which turning and looking about is frequently followed by
the reinforcement of seeing a fox," i.e, his
behavior is a discriminated operant. This explanation is unconvincing. B may
never have seen a fox and may have no current interest in seeing one, and yet
may react appropriately to the stimulus fox.35 Since exactly the
same behavior may take place when neither of the assumptions is fulfilled, some
other mechanism must be operative here.
Skinner remarks several times that his analysis of the tact
in terms of stimulus control is an improvement over the traditional
formulations in terms of reference and meaning. This is simply not true. His
analysis is fundamentally the same as the traditional one, though much less
carefully phrased. In particular, it differs only by indiscriminate paraphrase
of such notions as denotation (reference) and connotation
(meaning), which have been kept clearly apart in traditional formulations, in
terms of the vague concept stimulus control. In one
traditional formulation a descriptive term is said to denote a set of entities
and to connote or designate a certain property or condition that an entity must
possess or fulfil if the term is to apply to it.36 Thus, the term vertebrate
refers to (denotes, is true of) vertebrates and connotes the property having
a spine or something of the sort. This connoted defining property is called
the meaning of the term. Two terms may have the same reference but different
meanings. Thus, it is apparently true that the creatures with hearts are all
and only the vertebrates. If so, then the term creature with a heart
refers to vertebrates and designates the property having a heart. This
is presumably a different property (a different general condition) from having
a spine; hence the terms vertebrate and creature with a heart are
said to have different meanings. This analysis is not incorrect
(for at least one sense of meaning), but its many limitations have frequently
been pointed out.37
The major problem is that there is no good way to decide whether
two descriptive terms designate the same property.38 As we have just
seen, it is not sufficient that they refer to the same objects. Vertebrate
and creature with a spine would be said to designate the same property
(distinct from that designated by creature with a heart). If we ask why
this is so, the only answer appears to be that the terms are synonymous. The
notion property thus seems somehow language-bound, and appeal to
"defining properties" sheds little light on questions of meaning and
synonymy.
Skinner accepts the traditional account in toto, as can be seen from his definition of a tact as a response under control of a property (stimulus)
of some physical object or event. We have found that the notion control
has no real substance and is perhaps best understood as a paraphrase of denote
or connote or, ambiguously, both. The only consequence of adopting the
new term stimulus control is that the important differences between
reference and meaning are obscured. It provides no new objectivity. The
stimulus controlling the response is determined by the response itself; there
is no independent and objective method of identification (see Section 3).
Consequently, when Skinner defines synonymy as the case in which
"the same stimulus leads to quite different responses" (118), we can
have no objection. The responses chair and red made alternatively
to the same object are not synonymous, because the stimuli are called
different. The responses vertebrate and creature with a spine
would be considered synonymous because they are controlled by the same property
of the object under investigation; in more traditional and no less scientific
terms, they evoke the same concept. Similarly, when metaphorical extension is
explained as due to "the control exercised by properties of the stimulus
which, though present at reinforcement, do not enter into the contingency
respected by the verbal community" (92; traditionally, accidental
properties), no objection can be raised which has not already been leveled
against the traditional account. Just as we could "explain" the
response Mozart to a piece of music in terms of subtle properties of the
controlling stimuli, we can, with equal facility, explain the appearance of the
response sun when no sun is present, as in Juliet is [like] the sun.
"We do so by noting that Juliet and the sun have common properties, at
least in their effect on the speaker" (93). Since any two objects have
indefinitely many properties in common, we can be certain that we will never be
at a loss to explain a response of the form A is like B, for arbitrary A
and B. It is clear, however, that Skinner's recurrent claim that his
formulation is simpler and more scientific than the traditional account has no
basis in fact.
Tacts under the control of private stimuli (Bloomfield's
"displaced speech") form a large and important class (130-46),
including not only such responses as familiar and beautiful, but
also verbal responses referring to past, potential, or future events or
behavior. For example, the response There
was an elephant at the zoo "must be understood as a response to
current stimuli, including events within the speaker himself" (143).39
If we now ask ourselves what proportion of the tacts
in actual life are responses to (descriptions of) actual current outside
stimulation, we can see just how large a role must be attributed to private
stimuli. A minute amount of verbal behavior, outside the nursery, consists of
such remarks as This is red and There
is a man. The fact that functional analysis must make such a heavy appeal
to obscure internal stimuli is again a measure of its actual advance over traditional
formulations.
IX
Responses under the control of prior verbal
stimuli are considered under a different heading from the tact. An echoic
operant is a response which "generates a sound pattern similar to that
of the stimulus" (55). It covers only cases of immediate imitation.40
No attempt is made to define the sense in which a child's echoic response is
"similar" to the stimulus spoken in the father's bass voice; it
seems, though there are no clear statements about this, that
Skinner would not accept the account of the phonologist
in this respect, but nothing else is offered. The development of an echoic
repertoire is attributed completely to differential
reinforcement. Since the speaker will do no more, according to Skinner, than
what is demanded of him by the verbal community, the degree of accuracy
insisted on by this community will determine the elements of the repertoire,
whatever these may be (not necessarily phonemes). "In a verbal community
which does not insist on a precise correspondence, an echoic repertoire may
remain slack and will be less successfully applied to novel patterns."
There is no discussion of such familiar phenomena as the accuracy with which a
child will pick up a second language or a local dialect in the course of
playing with other children, which seem sharply in conflict with these
assertions. No anthropological evidence is cited to support the claim that an
effective phonemic system does not develop (this is the substance of the quoted
remark) in communities that do not insist on precise correspondence.
A verbal response to a written stimulus (reading) is called
textual behavior.
Other verbal responses to verbal stimuli are
called intraverbal operants. Paradigm instances are the response four to the
stimulus two plus two or the response
The process of "getting someone to see
a point," to see something your way, or to understand a complex state of
affairs (e.g., a difficult political situation or a mathematical proof) is, for
Skinner, simply a matter of increasing the strength of the listener's already
available behavior.42 Since "the
process is often exemplified by relatively intellectual scientific or
philosophical discourse," Skinner considers it "all the more
surprising that it may be reduced to echoic, textual, or intraverbal
supplementation" (269). Again, it is only the vagueness and
latitude with which the notions strength and intraverbal response are used that save this from
absurdity. If we use these terms in their literal sense, it is clear that
understanding a statement cannot be equated to shouting it frequently in a
high-pitched voice (high response strength), and a clever and convincing
argument cannot be accounted for on the basis of a history of pairings of
verbal responses.43
X
A final class of operants, called
autoclitics, includes those that are involved
in assertion, negation, quantification, qualification
of responses, construction of sentences, and the "highly complex
manipulations of verbal thinking." All these acts are to be explained
"in terms of behavior which is evoked by or acts upon other behavior of
the speaker" (313). Autoclitics are, then,
responses to already given responses, or rather, as we find in reading through
this section, they are responses to covert or incipient or potential verbal
behavior. Among the autoclitics are listed such
expressions as I recall, I imagine, for example, assume, let X equal...,
the terms of negation, the is of predication and
assertion, all, some, if, then, and, in general, all morphemes other
than nouns, verbs, and adjectives, as well as grammatical processes of ordering
and arrangement. Hardly a remark in this section can be accepted without
serious qualification. To take just one example, consider Skinner's account of
the autoclitic all in All swans are white
(329). Obviously we cannot assume that this is a tact
to all swans as stimulus. It is suggested, therefore, that we take all
to be an autoclitic modifying the whole sentence Swans
are white. All can then be taken as equivalent to always, or always
it is possible to say. Notice, however, that the modified sentence Swans
are white is just as general as All
swans are white. Furthermore, the proposed translation of all is
incorrect if taken literally. It is just as possible to say Swans are green
as to say Swans are white. It is not always possible to say either
(e.g., while you are saying something else or sleeping). Probably what Skinner
means is that the sentence can be paraphrased "X is white is true,
for each swan X." But this paraphrase cannot be given within his system,
which has no place for true.
Skinner's account of grammar and syntax as autoclitic processes (Chap. 13) differs
from a familiar traditional account mainly in the use of the pseudo-scientific
terms control or evoke in place of the traditional refer. Thus, in The boy runs, the final s of runs is
a tact under control of such "subtle properties of a situation" as
"the nature of running as an activity rather than an object or
property of an object."44 (Presumably, then,
in The attempt fails, The difficulty
remains, His anxiety increases, etc., we must also say that the s
indicates that the object described as the attempt is carrying out the activity
of failing, etc.) In the boy's gun, however, the s denotes
possession (as, presumably, in the boy's arrival, ...
story, ... age, etc.) and is under the control of this "relational
aspect of the situation" (336). The "relational autoclitic
of order" (whatever it may mean to call the order of a set of responses a
response to them) in The boy runs the store
is under the control of an "extremely complex stimulus situation," namely,
that the boy is running the store (335). And in the hat and the shoe
is under the control of the property "pair." Through in the
dog went through the hedge is under the control of the "relation
between the going dog and the hedge" (342). In general, nouns are evoked
by objects, verbs by actions, and so on. Skinner considers a sentence to be a
set of key responses (nouns, verbs, adjectives) on a skeletal frame (346). If
we are concerned with the fact that Sam rented a leaky boat, the raw responses to
the situation are rent, boat, leak, and Sam. Autoclitics
(including order) which qualify these responses, express relations between
them, and the like, are then added by a process called composition and
the result is a grammatical sentence, one of many alternatives among which
selection is rather arbitrary. The idea that sentences consist of
lexical items placed in a grammatical frame is of course a traditional one,
within both philosophy and linguistics. Skinner adds to it only the very
implausible speculation that in the internal process of composition, the nouns,
verbs, and adjectives are chosen first and then are arranged, qualified, etc.,
by autoclitic responses to these internal activities.45
This view of sentence structure, whether phrased in terms
of autoclitics, syncategorematic
expressions, or grammatical and lexical morphemes, is inadequate. Sheep
provide wool has no (physical) frame at all, but no other arrangement of
these words is an English sentence. The sequences furiously sleep ideas
green colorless and friendly young dogs seem harmless have the same
frames, but only one is a sentence of English (similarly, only one of the
sequences formed by reading these from back to front). Struggling artists
can be a nuisance has the same frame as marking papers can be a nuisance,
but is quite different in sentence structure, as can be seen by replacing can
be by is or are in both cases. There are many other similar
and equally simple examples. It is evident that more is involved in sentence
structure than insertion of lexical items in grammatical frames; no approach to
language that fails to take these deeper processes into account can possibly
achieve much success in accounting for actual linguistic behavior.
XI
The preceding discussion covers all the major notions that
Skinner introduces in his descriptive system. My purpose in discussing the
concepts one by one was to show that in each case, if we take his terms in
their literal meaning, the description covers almost no aspect of verbal
behavior, and if we take them metaphorically, the description offers no
improvement over various traditional formulations. The terms borrowed from
experimental psychology simply lose their objective meaning with this
extension, and take over the full vagueness of ordinary language. Since Skinner
limits himself to such a small set of terms for paraphrase, many important
distinctions are obscured. I think that this analysis supports the
view expressed in Section I, that elimination of the independent contribution
of the speaker and learner (a result which Skinner considers of great
importance, cf. 311-12) can be achieved only at the cost of eliminating all
significance from the descriptive system, which then operates at a level so
gross and crude that no answers are suggested to the most elementary questions.46 The questions to
which Skinner has addressed his speculations are hopelessly premature. It is
futile to inquire into the causation of verbal behavior until much more is
known about the specific character of this behavior; and there is little point
in speculating about the process of acquisition without much better
understanding of what is acquired.
Anyone who seriously approaches the study of linguistic
behavior, whether linguist, psychologist, or philosopher, must quickly become
aware of the enormous difficulty of stating a problem which will define the
area of his investigations, and which will not be either completely trivial or
hopelessly beyond the range of present-day understanding and technique. In
selecting functional analysis as his problem, Skinner has set himself a task of
the latter type. In an extremely interesting and insightful paper,47 K. S. Lashley has implicitly delimited a class of problems which
can be approached in a fruitful way by the linguist and psychologist, and which
are clearly preliminary to those with which Skinner is concerned. Lashley recognizes, as anyone must who seriously considers
the data, that the composition and production of an utterance is not simply a
matter of stringing together a sequence of responses under the control of
outside stimulation and intraverbal association, and
that the syntactic organization of an utterance is not something directly
represented in any simple way in the physical structure of the utterance
itself. A variety of observations lead him to conclude that syntactic structure
is "a generalized pattern imposed on the specific acts as they occur"
(512), and that "a consideration of the structure of the sentence and
other motor sequences will show...that there are, behind the overtly expressed
sequences, a multiplicity of integrative processes which can only be inferred
from the final results of their activity" (509). He also comments on the
great difficulty of determining the "selective mechanisms" used in
the actual construction of a particular utterance (522).
Although present-day linguistics cannot provide a precise
account of these integrative processes, imposed patterns, and selective
mechanisms, it can at least set itself the problem of characterizing these
completely. It is reasonable to regard the grammar of a language L ideally as a
mechanism that provides an enumeration of the sentences of L in something like
the way in which a deductive theory gives an enumeration of a set of theorems.
(Grammar, in this sense of the word, includes phonology.) Furthermore, the
theory of language can be regarded as a study of the formal properties of such
grammars, and, with a precise enough formulation, this general theory can
provide a uniform method for determining, from the process of generation of a
given sentence, a structural description which can give a good deal of insight
into how this sentence is used and understood. In short, it should be possible
to derive from a properly formulated grammar a statement of the integrative
processes and generalized patterns imposed on the specific acts that constitute
an utterance. The rules of a grammar of the appropriate form can be subdivided
into the two types, optional and obligatory; only the latter must be applied in
generating an utterance. The optional rules of the grammar can be viewed, then,
as the selective mechanisms involved in the production of a particular
utterance. The problem of specifying these integrative processes and selective
mechanisms is nontrivial and not beyond the range of
possible investigation. The results of such a study might, as Lashley suggests, be of independent interest for psychology
and neurology (and conversely). Although such a study, even if successful,
would by no means answer the major problems involved in the investigation of
meaning and the causation of behavior, it surely will not be unrelated to
these. It is at least possible, furthermore, that such a notion as semantic
generalization, to which such heavy appeal is made in all approaches to
language in use, conceals complexities and specific structure of inference not
far different from those that can be studied and exhibited in the case of
syntax, and that consequently the general character of the results of syntactic
investigations may be a corrective to oversimplified approaches to the theory
of meaning.
The behavior of the speaker, listener, and learner of
language constitutes, of course, the actual data for any study of language. The
construction of a grammar which enumerates sentences in such a way that a
meaningful structural description can be determined for each sentence does not
in itself provide an account of this actual behavior. It merely characterizes
abstractly the ability of one who has mastered the language to distinguish
sentences from nonsentences, to understand new sentences
(in part), to note certain ambiguities, etc. These are very remarkable
abilities. We constantly read and hear new sequences of words, recognize them
as sentences, and understand them. It is easy to show that the new events that
we accept and understand as sentences are not related to those with which we
are familiar by any simple notion of formal (or semantic or statistical)
similarity or identity of grammatical frame. Talk of generalization in this
case is entirely pointless and empty. It appears that we recognize a new item
as a sentence not because it matches some familiar item in any simple way, but
because it is generated by the grammar that each individual has somehow and in
some form internalized. And we understand a new sentence, in part, because we
are somehow capable of determining the process by which this sentence is
derived in this grammar.
Suppose that we manage to construct grammars having the
properties outlined above. We can then attempt to describe and study the
achievement of the speaker, listener, and learner. The speaker and the
listener, we must assume, have already acquired the capacities characterized
abstractly by the grammar. The speaker's task is to select a particular
compatible set of optional rules. If we know, from grammatical study, what
choices are available to him and what conditions of compatibility the choices
must meet, we can proceed meaningfully to investigate the factors that lead him
to make one or another choice. The listener (or reader) must determine, from an
exhibited utterance, what optional rules were chosen in the construction of the
utterance. It must be admitted that the ability of a human being to do this far
surpasses our present understanding. The child who learns a language has in
some sense constructed the grammar for himself on the basis of his observation
of sentences and nonsentences (i.e., corrections by
the verbal community). Study of the actual observed ability of a speaker to
distinguish sentences from nonsentences, detect
ambiguities, etc., apparently forces us to the conclusion that this grammar is
of an extremely complex and abstract character, and that the young child has
succeeded in carrying out what from the formal point of view, at least, seems
to be a remarkable type of theory construction. Furthermore, this task is
accomplished in an astonishingly short time, to a large extent independently of
intelligence, and in a comparable way by all children. Any theory of learning
must cope with these facts.
It is not easy to accept the view that a child is capable
of constructing an extremely complex mechanism for generating a set of
sentences, some of which he has heard, or that an adult can instantaneously
determine whether (and if so, how) a particular item is generated by this
mechanism, which has many of the properties of an abstract deductive theory.
Yet this appears to be a fair description of the performance of the speaker,
listener, and learner. If this is correct, we can predict that a direct attempt
to account for the actual behavior of speaker, listener, and learner, not based
on a prior understanding of the structure of grammars, will achieve very
limited success. The grammar must be regarded as a component in the behavior of
the speaker and listener which can only be inferred, as Lashley
has put it, from the resulting physical acts. The fact that all
normal children acquire essentially comparable grammars of great complexity
with remarkable rapidity suggests that human beings are somehow specially
designed to do this, with data-handling or "hypothesis-formulating"
ability of unknown character and complexity.48 The study of
linguistic structure may ultimately lead to some significant insights into this
matter. At the moment the question cannot be seriously posed, but in principle
it may be possible to study the problem of determining what the built-in
structure of an information-processing (hypothesis-forming) system must be to
enable it to arrive at the grammar of a language from the available data in the
available time. At any rate, just as the attempt to eliminate the contribution
of the speaker leads to a "mentalistic"
descriptive system that succeeds only in blurring important traditional
distinctions, a refusal to study the contribution of the child to language
learning permits only a superficial account of language acquisition, with a
vast and unanalyzed contribution attributed to a step called generalization
which in fact includes just about everything of interest in this process. If
the study of language is limited in these ways, it seems inevitable that major
aspects of verbal behavior will remain a mystery.
Notes
1 Skinner's confidence
in recent achievements in the study of animal behavior and their applicability
to complex human behavior does not appear to be widely shared. In many recent
publications of confirmed behaviorists there is a prevailing note of skepticism
with regard to the scope of these achievements. For representative comments,
see the contributions to Modern Learning Theory (by W. K. Estes et al.;
2 In Behavior of
Organisms (New York: Appleton-Century-Crofts, Inc., 1938), Skinner remarks
that "although a conditioned operant is the result of the correlation of
the response with a particular reinforcement, a relation between it and a
discriminative stimulus acting prior to the response is the almost universal
rule" (178-79). Even emitted behavior is held to be produced by some sort of
"originating force" (51) which, in the case
of operant behavior is not under experimental control. The distinction between
eliciting stimuli, discriminated stimuli, and "originating forces"
has never been adequately clarified and becomes even more confusing when
private internal events are considered to be discriminated stimuli (see below).
3 In a famous
experiment, chimpanzees were taught to perform complex tasks to receive tokens
which had become secondary reinforcers because of
association with food. The idea that money, approval, prestige, etc. actually
acquire their motivating effects on human behavior according to this paradigm
is unproved, and not particularly plausible. Many psychologists within the
behaviorist movement are quite skeptical about this (cf. 23n). As in the case
of most aspects of human behavior, the evidence about secondary reinforcement
is so fragmentary, conflicting, and complex that almost any view can find some
support.
4 Skinner's remark
quoted above about the generality of his basic results must be understood in
the light of the experimental limitations he has imposed. If it were true in
any deep sense that the basic processes in language are well understood and
free of species restriction, it would be extremely odd that language is limited
to man. With the exception of a few scattered observations (cf. his article,
"A Case History in Scientific Method," The American Psychologist,
11 [1956] 221-33), Skinner is apparently basing this claim on the fact that
qualitatively similar results are obtained with bar pressing of rats and
pecking of pigeons under special conditions of deprivation and various schedules
of reinforcement. One immediately questions how much can be based on these
facts, which are in part at least an artifact traceable to experimental design
and the definition of stimulus and response in terms of smooth
dynamic curves (see below). The dangers inherent in any attempt to extrapolate
to complex behavior from the study of such simple responses as bar pressing
should be obvious and have often been commented on (cf., e.g.,
5 An analogous
argument, in connection with a different aspect of Skinner's thinking, is given
by M. Scriven in "A Study of Radical
Behaviorism," Univ. of Minn. Studies in Philosophy of Science, I.
Cf. Verplanck's contribution to Modern Learning
Theory, op. cit. pp. 283-88, for more general discussion of the
difficulties in formulating an adequate definition of stimulus and response.
He concludes, quite correctly, that in Skinner's sense of the word, stimuli are
not objectively identifiable independently of the resulting behavior, nor are
they manipulable. Verplanck
presents a clear discussion of many other aspects of Skinner's system,
commenting on the untestability of many of the
so-called "laws of behavior" and the limited scope of many of the
others, and the arbitrary and obscure character of Skinner's notion of lawful
relation; and, at the same time, noting the importance of the experimental
data that Skinner has accumulated.
6 In Behavior of
Organisms, Skinner apparently was willing to accept this consequence. He
insists (41-42) that the terms of casual description in the popular vocabulary
are not validly descriptive until the defining properties of stimulus and
response are specified, the correlation is demonstrated experimentally, and the
dynamic changes in it are shown to be lawful. Thus, in describing a child as
hiding from a dog, "it will not be enough to dignify the popular
vocabulary by appealing to essential properties of dogness
or hidingness and to suppose them intuitively
known." But this is exactly what Skinner does in the book under review, as
we will see directly.
7 253f. and elsewhere, repeatedly.
As an example of how well we can control behavior using the notions developed
in this book, Skinner shows here how he would go about evoking the response pencil.
The most effective way, he suggests, is to say to the subject, "Please say
pencil" (our chances would, presumably, be even further improved by
use of "aversive stimulation," e.g., holding a gun to his head). We
can also "make sure that no pencil or writing instrument is available,
then hand our subject a pad of paper appropriate to pencil sketching, and offer
him a handsome reward for a recognizable picture of a cat." It would also
be useful to have voices saying pencil or pen and ... in the
background; signs reading pencil or pen and ...; or to place a
"large and unusual pencil in an unusual place clearly in sight."
"Under such circumstances, it is highly probable that our subject will say
pencil." "The available techniques are all illustrated in this
sample." These contributions of behavior theory to the practical control
of human behavior are amply illustrated elsewhere in the book, as when Skinner
shows (113-14) how we can evoke the response red (the device suggested
is to hold a red object before the subject and say, "Tell me what color
this is").
In fairness, it must be mentioned that there are certain
nontrivial applications of operant conditioning to the control of human
behavior. A wide variety of experiments have shown that the number of plural
nouns (for example) produced by a subject will increase if the experimenter
says "right" or "good" when one is produced (similarly,
positive attitudes on a certain issue, stories with particular content, etc.;
cf. L. Krasner, "Studies of the Conditioning of
Verbal Behavior," Psych. Bull., 55 [1958], for a survey of several
dozen experiments of this kind, mostly with positive results). It is of some
interest that the subject is usually unaware of the process. Just what insight
this gives into normal verbal behavior is not obvious. Nevertheless, it is an
example of positive and not totally expected results using the Skinnerian
paradigm.
8 "Are Theories
of Learning Necessary?", Psych. Rev., 57
(1950), 193-216.
9 And elsewhere. In
his paper "Are Theories of Learning Necessary?" Skinner considers the
problem how to extend his analysis of behavior to experimental situations in
which it is impossible to observe frequencies, rate of response being the only
valid datum. His answer is that "the notion of probability is usually
extrapolated to cases in which a frequency analysis cannot be carried out. In
the field of behavior we arrange a situation in which frequencies are available
as data, but we use the notion of probability in analyzing or formulating
instances of even types of behavior which are not susceptible to this
analysis" (199). There are, of course, conceptions of probability not
based directly on frequency, but I do not see how any of these apply to the
cases that Skinner has in mind. I see no way of interpreting the quoted passage
other than as signifying an intention to use the word probability in
describing behavior quite independently of whether the notion of probability is
at all relevant.
10 Fortunately,
"In English this presents no great difficulty" since, for example,
"relative pitch levels ... are not ... important" (25). No reference
is made to the numerous studies of the function of relative pitch levels and
other intonational features in English.
11 The vagueness of
the word tendency, as opposed to frequency, saves the latter
quotation from the obvious incorrectness of the former. Nevertheless, a good
deal of stretching is necessary. If tendency has anything like its
ordinary meaning, the remark is clearly false. One may believe strongly the
assertion that Jupiter has four moons, that many of Sophocles' plays have been
irretrievably lost, that the earth will burn to a crisp in ten million years,
and so on, without experiencing the slightest tendency to act upon these verbal
stimuli. We may, of course, turn Skinner's assertion into a very unilluminating truth by defining "tendency to
act" to include tendencies to answer questions in certain ways, under
motivation to say what one believes is true.
12 One should add,
however, that it is in general not the stimulus as such that is reinforcing,
but the stimulus in a particular situational context. Depending on experimental
arrangement, a particular physical event or object may be reinforcing,
punishing, or unnoticed. Because Skinner limits himself to a particular, very
simple experimental arrangement, it is not necessary for him to add this
qualification, which would not be at all easy to formulate precisely. But it is
of course necessary if he expects to extend his descriptive system to behavior
in general.
13 This has been
frequently noted.
14 See, for example,
"Are Theories of Learning Necessary?", op.
cit., p. 199. Elsewhere, he suggests that the term learning be
restricted to complex situations, but these are not characterized.
15 "A child
acquires verbal behavior when relatively unpatterned
vocalizations, selectively reinforced, gradually assume forms which produce
appropriate consequences in a given verbal community" (31).
"Differential reinforcement shapes up all verbal forms, and when a prior
stimulus enters into the contingency, reinforcement is responsible for its
resulting control.... The availability of behavior, its probability or strength,
depends on whether reinforcements continue in effect and according to
what schedules" (203-4); elsewhere, frequently.
16 Talk of schedules
of reinforcement here is entirely pointless. How are we to decide, for example,
according to what schedules covert reinforcement is arranged, as in thinking or
verbal fantasy, or what the scheduling is of such factors as silence, speech,
and appropriate future reactions to communicated information?
17 See, for example,
N. E. Miller and J. Dollard, Social Learning and
Imitation (New York, 1941), pp. 82-83, for a discussion of the
"meticulous training" that they seem to consider necessary for a
child to learn the meanings of words and syntactic patterns. The same notion is
implicit in O. H. Mowrer's speculative account of how
language might be acquired, in Learning Theory and Personality Dynamics,
(New York: The Ronald Press, Inc., 1950), Chap. 23. Actually, the view appears
to be quite general.
18 For a general
review and analysis of this literature, see D. L. Thistlethwaite,
"A Critical Review of Latent Learning and Related Experiments," Psych.
Bull., 48 (1951), 97-129. K. MacCorquodale and P.
E. Meehl, in their contribution to Modern Learning
Theory op. cit., carry out a serious and considered attempt to handle the
latent learning material from the standpoint of drive-reduction theory, with
(as they point out) not entirely satisfactory results. W. H. Thorpe reviews the
literature from the standpoint of the ethologist,
adding also material on homing and topographical orientation (Learning and
Instinct in Animals [Cambridge, 1956]).
19 Theories of Learning, 214 (1956).
20 O. E. Berlyne, "Novelty and Curiosity as Determinants of
Exploratory Behavior," Brit. Jour. of Psych., 41 (1950), 68-80; id.,
"Perceptual Curiosity in the Rat," Jour. of Comp. Physiol. Psych., 48 (1955), 238-46; W. R. Thompson and
L. M. Solomon, "Spontaneous Pattern Discrimination in the Rat," ibid., 47 (1954), 104-7.
21 K. C. Montgomery,
"The Role of the
22 R. A. Butler,
"Discrimination Learning by Rhesus Monkeys to Visual-Exploration
Motivation," ibid., 46 (1953), 95-98. Later
experiments showed that this "drive" is highly persistent, as opposed
to derived drives which rapidly extinguish.
23 H. F. Harlow, M.
K. Harlow, and D. R. Meyer, "Learning Motivated by a
24 Thus, J. S.
Brown, in commenting on a paper of Harlow's in Current
Theory and Research in Motivation (Lincoln: Univ. of Nebraska Press, 1953),
argues that "in probably every instance [of the experiments cited by
Harlow] an ingenious drive-reduction theorist could find some fragment of fear,
insecurity, frustration, or whatever, that he could insist was reduced and
hence was reinforcing" (53). The same sort of thing could be said for the
ingenious phlogiston or ether theorist.
25 Cf. H. G. Birch and
M. E. Bitterman, "Reinforcement and Learning:
The process of Sensory Integration," Psych. Rev., 56 (1949),
292-308.
26 See, for example,
his paper "A Physiological Study of Reward" in D. C. McClelland, ed.,
Studies in Motivation (New York: Appleton-Century-Crafts, Inc., 1955),
pp. 134-43.
27 See Thorpe, op.
cit., particularly pp. 115-18 and 337-76, for an excellent discussion of this
phenomenon, which has been brought to prominence particularly by the work of K.
Lorenz (cf. "Der Kumpan
in der Umwelt des Vogels," parts of which are reprinted in English
translation in C. M. Schiller, ed., Instinctive Behavior [New York:
International Universities Press, 1957], pp. 83-128).
28 Op. cit.,
p. 372.
29 See, e.g., J. Jaynes, "Imprinting: Interaction of Learned and Innate
Behavior," Jour. of Comp. Physiol. Psych.,
49 (1956), 201-6, where the conclusion is reached that "the experiments
prove that without any observable reward, young birds of this species follow a
moving stimulus object and very rapidly come to prefer that object to
others."
30 Of course, it is
perfectly possible to incorporate this fact within the Skinnerian framework.
If, for example, a child watches an adult using a comb and then, with no
instruction, tries to comb his own hair, we can explain this act by saying that
he performs it because he finds it reinforcing to do so, or because of the
reinforcement provided by behaving like a person who is "reinforcing"
(cf. 164). Similarly, an automatic explanation is available for any other
behavior. It seems strange at first that Skinner pays so little attention to
the literature on latent learning and related topics, considering the
tremendous reliance that he places on the notion of reinforcement; I have seen
no reference to it in his writings. Similarly, F. S. Keller and W. N. Schoenfeld, in what appears to be the only text written
under predominantly Skinnerian influence, Principles of Psychology (New
York: Appleton-Century-Crofts, Inc., 1950), dismiss the latent learning
literature in one sentence as "beside the point," serving only
"to obscure, rather than clarify, a fundamental principle" (the
law of effect, 41). However, this neglect is perfectly appropriate in
Skinner's case. To the drive-reductionist, or anyone
else for whom the notion reinforcement has some substantive meaning,
these experiments and observations are important (and often embarrassing). But
in the Skinnerian sense of the word, neither these results nor any conceivable
others can cast any doubt on the claim that reinforcement is essential for the
acquisition and maintenance of behavior. Behavior certainly has some
concomitant circumstances, and whatever they are, we can call them reinforcement.
31 Tinbergen, op.cit.,
Chap. VI, reviews some aspects of this problem, discussing the primary role of
maturation in the development of many complex motor patterns (e.g., flying,
swimming) in lower organisms, and the effect of an "innate disposition to
learn" in certain specific ways and at certain specific times. Cf. also P.
Schiller, "Innate Motor Action as a Basis for Learning," in C. H.
Schiller, ed., Instinctive Behavior (New York: International
Universities Press, 1957), pp. 265-88, for a discussion of the role of maturing
motor patterns in apparently insightful behavior in the chimpanzee.
Lenneberg ("The Capacity for Language Acquisition", in J.
A. Fodor, ed., The Structure of Language [Prentice-Hall, Inc., 1964])
presents a very interesting discussion of the part that biological structure
may play in the acquisition of language, and the dangers in neglecting this
possibility.
32 From among many
cited by Tinbergen, op. cit., p. 85.
33 Cf. K. S. Lashley, "In Search of
the Engram," Symposium of the Society for
Experimental Biology, 4 (1950), 454-82. R. Sperry, "On the
Neural Basis of the Conditioned Response," British Journal of Animal
Behavior, 3 (1955), 41-44, argues that to account for the experimental
results of Lashley and others, and for other facts
that he cites, it is necessary to assume that high-level cerebral activity of
the type of insight, expectancy, and so on is involved even in simple
conditioning. He states that "we still lack today a satisfactory picture
of the underlying neural mechanism" of the conditioned response.
34 Furthermore, the
motivation of the speaker does not, except in the simplest cases, correspond in
intensity to the duration of deprivation. An obvious counter-example is what Hebb has called the "salted-nut phenomenon" (Organization
of Behavior [New York, 1949], p. 199). The difficulty is of course even
more serious when we consider deprivations not related to physiological
drives.
35 Just as he may
have the appropriate reaction, both emotional and behavioral, to such
utterances as the volcano is erupting or there's a homicidal maniac
in the next room without any previous pairing of the verbal and the
physical stimulus. Skinner's discussion of Pavlovian
conditioning in language (154) is similarly unconvincing.
36 J. S. Mill, A System of Logic (1843). R. Carnap gives a recent reformulation in "Meaning and
Synonymy in Natural Languages," Phil. Studies, 6 (1955), 33-47,
defining the meaning (intension) of a predicate Q for a speaker X as "the
general condition which an object y must fulfil
in order for X to be willing to ascribe the predicate Q to y." The
connotation of an expression is often said to constitute its "cognitive
meaning" as opposed to its "emotive meaning," which is,
essentially, the emotional reaction to the expression.
Whether or not this is the best way to approach meaning, it
is clear that denotation, cognitive meaning, and emotive meaning are quite
different things. The differences are often obscured in empirical studies of
meaning, with much consequent confusion. Thus, Osgood has set himself the task
of accounting for the fact that a stimulus comes to be a sign for another
stimulus (a buzzer becomes a sign for food, a word for a thing, etc.). This is
clearly (for linguistic signs) a problem of denotation. The method that he
actually develops for quantifying and measuring meaning (cf. C. E. Osgood, G. Suci, P. Tannenbaum, The
Measurement of Meaning [Urbana: Univ. of Illinois Press, 1957]) applies,
however, only to emotive meaning. Suppose, for example, that A hates both
Hitler and science intensely, and considers both highly potent and
"active," while B, agreeing with A about Hitler, likes science very
much, although he considers it rather ineffective and not too important. Then,
A may assign to "Hitler" and "science" the same position on
the semantic differential, while B will assign "Hitler" the same
position as A did, but "science" a totally different position. Yet, A
does not think that "Hitler" and "science" are synonymous
or that they have the same reference, and A and B may
agree precisely on the cognitive meaning of "science." Clearly, it is
the attitude toward the things (the emotive meaning of the words) that is being
measured here. There is a gradual shift in Osgood's account from denotation to
cognitive meaning to emotive meaning. The confusion is caused, no doubt, by the
fact that the term meaning is used in all three senses (and others).
[See J. Carroll's review of the book by Osgood, Suci,
and Tannenbaum in Language, 35, No. 1 (1959).]
37 Most clearly by Quine. See From a Logical Point of View (
38 A method for
characterizing synonymy in terms of reference is suggested by Goodman, "On
Likeness of Meaning," Analysis, 10 (1949), 1-7. Difficulties are
discussed by Goodman, "On Some Differences about Meaning," ibid., 13 (1953) 90-96. Carnap,
op. cit., presents a very similar idea (Section 6), but somewhat
misleadingly phrased, since he does not bring out the fact that only
extensional (referential) notions are being used.
39 In general, the
examples discussed here are badly handled, and the success of the proposed
analyses is overstated. In each case, it is easy to see that the proposed
analysis, which usually has an air of objectivity, is not equivalent to the
analyzed expression. To take just one example, the response I am looking for
my glasses is certainly not equivalent to the proposed paraphrases:
"When I have behaved in this way in the past, I have found my glasses and
have then stopped behaving in this way," or "Circumstances have
arisen in which I am inclined to emit any behavior which in the past has led to
the discovery of my glasses; such behavior includes the behavior of looking in
which I am now engaged." One may look for one's glasses for the first
time; or one may emit the same behavior in looking for one's glasses as in
looking for one's watch, in which case I am looking for my glasses and I
am looking for my watch are equivalent, under the Skinnerian paraphrase.
The difficult questions of purposiveness cannot be
handled in this superficial manner.
40 Skinner takes
great pains, however, to deny the existence in human beings (or parrots) of any
innate faculty or tendency to imitate. His only argument is that no one would
suggest an innate tendency to read, yet reading and
echoic behavior have similar "dynamic properties." This similarity,
however, simply indicates the grossness of his descriptive categories. In the
case of parrots, Skinner claims that they have no instinctive capacity to imitate,
but only to be reinforced by successful imitation (59). Given Skinner's use of
the word reinforcement, it is difficult to perceive any distinction
here, since exactly the same thing could be said of any other instinctive
behavior. For example, where another scientist would say that a certain bird
instinctively builds a nest in a certain way, we could
say in Skinner's terminology (equivalently) that the bird is instinctively
reinforced by building the nest in this way. One is therefore inclined to dismiss
this claim as another ritual introduction of the word reinforce. Though
there may, under some suitable clarification, be some truth in it, it is
difficult to see how many of the cases reported by competent observers can be
handled if reinforcement is given some substantive meaning. Cf. Thorpe, op.
cit. p. 353f.; K. Lorenz, King Solomon's Ring (New York, 1952), pp.
85-88; even Mowrer, who tries to show how imitation
might develop through secondary reinforcement, cites a case, op. cit.,
p. 694, which he apparently believes, but where this could hardly be true. In
young children, it seems most implausible to explain imitation in terms of
secondary reinforcement.
41 Although even
this possibility is limited. If we were to take these paradigm instances
seriously, it should follow that a child who knows how to count from one to 100
could learn an arbitrary 10 x 10 matrix with these numbers as entries as
readily as the multiplication table.
42 Similarly,
"the universality of a literary work refers to the number of potential
readers inclined to say the same thing" (275; i.e., the most
"universal" work is a dictionary of clich�s
and greetings) a speaker is "stimulating" if he says what we are
about to say ourselves (272) etc.
43 Similarly,
consider Skinner's contention (362-65) that communication of knowledge or facts
is just the process of making a new response available to the speaker. Here the
analogy to animal experiments is particularly weak. When we train a rat to
carry out some peculiar act, it makes sense to consider this a matter of adding
a response to his repertoire. In the case of human communication, however, it
is very difficult to attach any meaning to this terminology. If A imparts to B
the information (new to B) that the railroads face collapse, in what sense can
the response The railroads face collapse be said to be now, but not
previously, available to B? Surely B could have said it before (not knowing
whether it was true), and known that it was a sentence (as opposed to Collapse
face railroads the). Nor is there any reason to assume that the response
has increased in strength, whatever this means exactly (e.g., B may have no
interest in the fact, or he may want it suppressed). It is not clear how we can
characterize this notion of "making a response available" without
reducing Skinner's account of "imparting knowledge" to a triviality.
44 (332). On the next page, however, the s in the same
example indicates that "the object described as the boy possesses
the property of running." The difficulty of even maintaining consistency
with a conceptual scheme like this is easy to appreciate.
45 One might just as
well argue that exactly the opposite is true. The study of hesitation pauses
has shown that these tend to occur before the large categories -- noun, verb,
adjective; this finding is usually described by the statement that the pauses
occur where there is maximum uncertainty or information. Insofar as hesitation
indicates on-going composition (if it does at all), it would appear that the
"key responses" are chosen only after the "grammatical
frame." Cf. C. E. Osgood, unpublished paper; F. Goldman-Eisler, "Speech Analysis and Mental Processes," Language
and Speech, 1 (1958), 67.
46 E.g., what are in
fact the actual units of verbal behavior? Under what conditions will a physical
event capture the attention (be a stimulus) or be a reinforcer?
How do we decide what stimuli are in "control" in a specific case?
When are stimuli "similar"? And so on. (It is not interesting to be
told, e.g., that we say Stop to an automobile or billiard ball because
they are sufficiently similar to reinforcing people [46].) The use of
unanalyzed notions like similar and generalization is
particularly disturbing, since it indicates an apparent lack of interest in
every significant aspect of the learning or the use of language in new
situations. No one has ever doubted that in some sense, language is learned by
generalization, or that novel utterances and situations are in some way similar
to familiar ones. The only matter of serious interest is the specific
"similarity." Skinner has, apparently, no interest in this. Keller
and Schoenfeld, op. cit., proceed to
incorporate these notions (which they identify) into their Skinnerian
"modern objective psychology" by defining two stimuli to be similar
when "we make the same sort of response to them" (124; but when are
responses of the "same sort"?). They do not seem to notice that this
definition converts their "principle of generalization" (116), under
any reasonable interpretation of this, into a tautology. It is obvious that such
a definition will not be of much help in the study of language learning or
construction of new responses in appropriate situations.
47 "The Problem of Serial Order in Behavior," in L. A. Jeffress, ed., Hixon
Symposium on Cerebral Mechanisms in Behavior (New York: John Wiley &
Sons Inc., 1951). Reprinted in F. A. Beach, D. O. Hebb, C. T. Morgan, H. W. Nissen,
eds., The Neuropsychology of Lashley
(New York: McGraw-Hill Book Company, 1960). Page references are to the
latter.
48 There is nothing
essentially mysterious about this. Complex innate behavior patterns and innate
"tendencies to learn in specific ways" have been carefully studied in
lower organisms. Many psychologists have been inclined to believe that such
biological structure will not have an important effect on acquisition of
complex behavior in higher organisms, but I have not been able to find any
serious justification for this attitude. Some recent studies have stressed the
necessity for carefully analyzing the strategies available to the organism,
regarded as a complex "information-processing system" (cf. J. S.
Bruner, J. J. Goodnow, and G. A. Austin, A Study
of Thinking [New York, 1956]; A. Newell, J. C. Shaw, and H. A. Simon,
"Elements of a Theory of Human Problem Solving," Psych. Rev.,
65, [1958], 151-66), if anything significant is to be said about the character
of human learning. These may be largely innate, or developed by early learning
processes about which very little is yet known. (But see Harlow, "The
Formation of Learning Sets," Psych. Rev., 56 (1949), 51-65, and
many later papers, where striking shifts in the character of learning are shown
as a result of early training; also D. O. Hebb, Organization
of Behavior, 109 ff.). They are undoubtedly quite complex. Cf. Lenneberg, op. cit., and R. B. Lees, review of N.
Chomsky's Syntactic Structures in Language, 33 (1957), 406f, for
discussion of the topics mentioned in this section.