6 PSYCHOLOGY AND BEHAVIOR race differentiation in man and the descent of man, but he looks upon these as special topics, equal in importance with his own yet ones in which his interests will never be vitally engaged. It is not fair to say that all of his work is directed toward human evolution or that it must be interpreted in terms of human evolution. He does not have to dismiss certain of his facts on the inheritance of coat color in mice because, forsooth, they have little bearing upon the differentiation of the genus Homo into separate races, or upon the descent of the genus Homo from some more primitive stock.
In psychology we are still in that stage of development where we feel that we must select our material. We have a general place of discard for processes, which we anathe- matize so far as their value for psychology is concerned by saying, ' ' this is a reflex; " ' ^ that is a purely physiological fact which has nothing to do with psychology." "We are not interested (as psychologists) in studying all of the processes of adjustment which the animal as a whole em- ploys, and in finding how these various responses are con- nected, and how they fall apart, thus working out a system- atic scheme for the prediction and control of response in general. Unless our observed facts are indicative of con- sciousness,.we have no use for them, and unless our ap- paratus and method are designed to throw such facts into relief, they are thought of in just as disparaging a way.
Psychology has failed signally during the fifty odd years of its existence as an experimental discipline to make its place in the world as an undisputed natural science. Psychology, as it is generally thought of, has something esoteric in its methods. If you fail to reproduce my find- ings it is not due to some fault in your apparatus or the control of j^our stimuli, but it is due to the fact that your introspection is untrained.^ The attack is made upon the ' In this connection attention is called to the controversy now on between the adherents and the opposers of imageless thought. The "types of reactors" (sensory and motor) was also a matter of bitter dispute. The complication experiment was likewise the source of a war of words concerning the accuracy of the opponent's introspection.
PSYCHOLOGY UNSCIENTIFIC 7 observer and not tipon the experimental setting. In physics and in chemistry the attack is made upon the experimental conditions. The apparatus was not sensitive enough, im- pure chemicals were used, etc. In these sciences a better technique will give reproducible results. Psychology is otherwise. If you can't observe 3 — 9 states of clearness in attention, your introspection is poor. If, on the other hand, a feeling seems reasonably clear to you, your in- trospection is again faulty. You are experiencing too much.
The time seems to have come when psychology must discard all reference to consciousness; when it need no longer delude itself into thinking that it is making mental states the object of observation. We have become so en- meshed in speculative cjuestions concerning the elements of mind, the nature of conscious content (e.g., imageless thought, attitudes, and Bewusstseinslage, etc.), that experi- mental students are beginning to feel that something is wrong with the premises and the types of problem which develop from them. There is no longer any guarantee that all mean the same thing when the terms now current in psychology are used. Take the case of sensation. A sensation is defined in terms of its attributes. One psy- chologist will state with readiness that the attributes of a visual sensation are quality^ extension, duration, and in- tensity. Another will add clearness. Still another that of order. It is questionable whether any one psychologist can draw up a set of statements describing what he means by sensation which will be agreed to by three other psy- chologists of different training. Turn for a moment to the question relating to the number of isolable sensations. Is there an extremely large number of color sensations, — or only four, red, green, yellow, and blue? Again, yellow, while psychologically simple, can be obtained by super- imposing red and green spectral rays upon the same dif- fusing surface! If, on the other hand, we say that every just noticeable difference in the spectrum is a simple sensation, and that every, just noticeable increase in the white value of a given color gives simple sensations, we 8 PSYCHOLOGY AND BEHAVIOR are forced to admit that the number is so large and the conditions for obtaining them so complex that the concept of sensation is unusable, either for the purpose of analysis or that of synthesis. Titchener, who has fought the most valiant fight in this country for a psychology based upon introspection, feels that these differences of opinion as to the number of sensations and their attributes; as to whether there are relations (in the sense of elements) and on the many others which seem to be fundamental in every at- tempt at analysis, are perfectly natural in the present undeveloped state of psychology. While it is admitted that every growing science is full of unanswered questions, surely only those who are wedded to the system as we now have it, who have fought and suffered for it, can confidently believe that there will ever be any greater uniformity than there is now in the answers we have to such questions. One must believe that two hundred years from now, unless the introspection method is discarded, psychology will still be divided on the question as to whether auditory 'Sensations have the quality of " extension," whether in- tensity is an attribute which can be applied to color, whether there is a difference in ' ' texture ' ' between image and sensation; and upon many hundreds of others of like character.
Our psychological quarrel is not with the systematic and structural psychologist alone. The last fifteen years have seen the growth of what is called functional psychology. This type of psychology decries the use of elements in the static sense of the structuralists. It is stated in words which seem to throw emphasis upon the biological signifi- cance of conscious processes rather than upon the analysis of conscious states into introspectively isolable elements. The difference between functional psychology and struc- tural psychology, as the functionalists have so far stated the case, is unintelligible. The terms sensation, perception, affection, emotion, volition are used as much by the func- tionalist as by the structuralist. The addition of the word " process " (" mental act as a whole " and like terms are frequently met) after each serves in some way to remove PSYCHOLOGY UNSCIENTIFIC 9 the corpse of " content " and to leave " function " in its stead. Surely if these concepts are elusive when looked at from a content standpoint, they are still more deceptive when viewed..from the angle of function, and espe- cially so when function is obtained by the introspective method.
One of the difficulties in the way of a consistent func- tional psychology is the parallelistic hypothesis. If the functionalist attempts to express his formulation in terms which make mental states really appear to function, to play some active role in the world of adjustment, he almost inevitably lapses into terms which are connotative of interaction. "When taxed with this he replies that it is more convenient to do so and that he does it to avoid the cir- cumlocutions and the clumsiness of statement which are inherent in any thoroughgoing parallelism. As a matter of fact the functionalist probably thinks in terms of inter- action and resorts to parallelism only when forced to give expression to his views. We advance the view that hehaviorism is the only consistent and logical functional- ism. In it one avoids both the Scylla of parallelism and the Charybdis of interaction. Those time-honored relics of philosophical speculation need trouble the student of be- havior as little as they trouble the student of physics. The consideration of the mind-body problem affects neither the type of problem selected nor the formulation of the solution of that problem.
The nature of the behaviorist's program. — This leads us to the point where argument should be made construc- tive. It is possible to write a psychology, to define it as Pillsbury does (as the " science of behavior "), and never go back upon the definition: never to use the terms con- sciousness, mental states, mind, content, will, imagery, and the like. It can be done naturally and conveniently in a few years from now without running into the absurd terminology of Beer, Bethe, Von Uexkiill, Nuel, and that of the so-called objective school generally. It can be done in terms of stimulus and response, in terms of habit formation, habit integration, and the like. Furthermore it is worth 10 PSYCHOLOGY AND BEHAVIOR while to make this attempt so far as animal psychology is concerned at the present time.
A psychology of interest to all scientific men would take as its starting point, first, the observable fact that organ- isms, man and animal alike, do adjust themselves to their environment by means of hereditary and habit equipments. These adjustments may be very adequate or they may be so. inadequate that the organism barely maintains its existence; secondly, certain stimuli lead the organisms to make the responses. In a system of psychology completely worked out, given the responses the stimuli can be pre- dicted; given the stimuli the responses can be predicted. Such a set of statements is crass and raw in the extreme, as all such generalizations must be. Yet they are hardly more raw and less realizable than the ones which appear in the psychology texts of the day. The point might better be illustrated by choosing an everyday problem which any one is likely to meet in the course of his work. Some time ago the author was called upon to make a study of certain species of birds. Until he went to Tortugas he had never seen these birds alive. On reaching this island he found the animals doing certain things: some of the acts seemed to work peculiarly well in such an environment, while others seemed to be unsuited to their type of life.
The responses of the group as a whole were first studied and later those of individuals. In order to understand more thoroughly the relation between what was habit and what was hereditary in these responses, the young birds were captured and reared. In this way it was possible to study the order of appearance of hereditary adjustments and their complexity, and later the beginnings of habit formation. The attempts to determine the stimuli which called forth such adjustments were crude indeed. Conse- quently the attempts to control behavior and to produce responses at will did not meet with much success: food and water, sex and other social relations, light and temperature conditions w^ere all beyond control in a field study. It was found possible to control their reactions in a measure by using the nest and egg (or young) as stimuli.
A BEHAVIORISTIC PROGRAM 11 It is not necessary here to develop further how such a study should be carried out and how work of this kind needs to be supplemented by carefully controlled laboratory experiments. Were the task to examine the behavior of some of the Australian tribes the method adopted would have been much the same, but the problem would have been more difficult: the types of responses called forth by physical stimuli would have been more varied, and the number of effective stimuli larger. The social setting of their lives would have had to be examined in a far more careful way. These savages would naturally be far more influenced by the responses of each other than was the case with the birds. Furthermore, habits would have been more complex and the influence of past habits upon present responses would have appeared more^ clearly. Similar but more complex problems would arise in working out the psychology of a cosmopolitan race, but the method of at- tacking them would be the same. In the main, the desire in all such work is to gain an accurate knowledge of ad- justments and the stimuli calling them forth. The reason for this is to learn general and particular methods by which behavior may be controlled. The goal is not ^' the description and explanation of states of consciousness as such," nor that of obtaining such proficiency in mental gymnastics that one can immediately lay hold of a state of consciousness and say, ' ' this, as a whole, consists of gray sensation number 350, of such and such extent, occurring in conjunction with the sensation of cold of a certain intensity; one of pressure of a certain intensity and ex- tent," and so on ad infi^iitum. If psychology would follow the plan suggested, the educator, the physician, the jurist, and the business man could utilize the data in a practical way, as soon as it could be experimentally obtained. Those who have occasion to apply psychological principles prac- tically would find no need to complain as they do at the present time. Ask any physician or jurist today whether scientific psychology plays a practical part in his daily routine and you will hear him deny that the psychology of the laboratories finds a place in his scheme of work.
12 PSYCHOLOGY AND BEHAVIOR The criticism is extremely just. One of the principal reasons which makes psychology an unattractive sub- ject is the fact that there is no realm of application for the principles which are being worked out in content terms.
What makes us hopeful that the behaviorist 's position is a defensible one is the fact that those branches of psy- chology which have already partially withdrawn from the parent, experimental psychology, and which are conse- quently less dependent upon introspection, are today in a most flourishing condition. Experimental pedagogy, the psychology of drugs, the psychology of advertising, legal psychology, the psychology of tests, and psychopathology are all vigorous growths. These are sometimes wrongly called ' ' practical " or ' ' applied ' ' psychology. Surely there was never a worse misnomer. In the future there may grow up vocational bureaus which really apply psychology. At present these fields are truly scientific and are in search of broad generalizations which will lead to the control of human behavior. E.g., we find out by experimentation whether a series of stanzas may be acquired more readily if the whole is learned at once, or whether it is more ad- vantageous to learn each stanza separately and then pass to the succeeding. We do not attempt to apply our find- ings. The application of this principle is purely voluntary on the part of the teacher. In the psychology of drugs we may show the effect on behavior of certain doses of caffeine. We may reach the conclusion that caffeine has a good effect upon the speed and accuracy of work. But these are general principles. We leave it to the individual as to whether the results of our tests shall be applied or not. Again, in legal testimony, we test the effects of recency upon the reliability of a witness's report. We test the accuracy of the report with respect to moving objects, stationary objects, color, etc. It depends upon the judicial machinery of the country whether these facts are ever to be applied. For a ' ' pure ' ' psychologist to say that he is not interested in the questions raised in these divi- sions of the science because they relate indirectly to the A BEHAVIORISTIC PROGRAM 13 application of psychology shows, in the first place, that he fails to understand the scientific aim in such problems, and secondly, that he is not interested in a psychology which concerns itself with human life. The only fault to be found wdth these disciplines is that much of their material is now stated in terms of introspection, whereas a state- ment in terms of objective results would be far more valu- able. There is no reason why appeal should ever be made to consciousness in any of them. Or why introspective data should ever be sought during the experimentation, or published in the results. In experimental pedagogy es- pecially we can see the desirability of keeping all of the results on a purely objective plane. If this is done, work there on the human being will be comparable directly with the work on animals.
We are more interested at the present moment in trying to show the necessity for maintaining uniformity in ex- perimental procedure and in the method of stating results in both human and animal w^ork than in enlarging upon the changes which are certain to come in the scope of human psychology. We shall examine for a moment the subject of the range of stimuli to which animals respond. Let us first consider the work upon vision in animals. We put our animal in a situation where he will respond (or learn to respond) positively to one of two monochromatic lights. We feed him at the one (positive) and punish him at the other (negative). In a short time the animal learns to go to the light at which he is fed. At this point questions arise which may be phrased in two ways: one may choose the psychological way and say, " does the animal see these two lights as the human being does, i.e., as two distinct colors, or does it see them as two grays differing in bright- ness, as do the totally color blind? " Phrased by the behaviorist it would read as follows: " Is my animal re- sponding upon the basis of the difference in intensity be- tween the two stimuli, or upon the difference in wave-lengths? " He nowhere thinks of the animal's response in terms of his own experiences of colors and grays. He^ wishes to establish the fact whether tvave-length is a 14 PSYCHOLOGY AND BEHAVIOR factor in that animal's adjustment.* If so, what wave- lengths are effective and what differences in wave-length must be maintained in the different spectral regions in order to afford bases for differential responses? If wave- length is not a factor in adjustment he wishes to know what difference in intensity will serve as a basis for response, and whether the difference obtained at any one point in the spectrum will suffice throughout the spectrum. Further- more, he wishes to test whether the animal can respond to wave-lengths which do not affect the human eye. He is as much interested in comparing the rat's spectral sensi- bility curve with that of the chick as in comparing it with man's. The point of view when the various sets of com- parisons are made does not change in the slightest.
However we phrase the question to ourselves, we take our animal after the association has been formed and introduce certain control experiments which enable us to return answers to the questions just raised. But there is just as keen a desire on our part to test man under the same conditions, and to state the results in both cases in common terms.
The man and the animal should be placed as nearly as possible under the same experimental conditions. Instead of feeding or punishing the human subject, we should ask him to respond by setting a second apparatus until stand- ard and control offered no basis for a differential response. Do we lay ourselves open to the charge here that we are using introspection? The reply is. Not at all; while we might very well feed the human subject for a right choice and punish him for a wrong one, and thus produce the re- sponse if the subject could give it, there is no need of going to extremes even on the platform we suggest. But it should be understood that we are merely using this second method as an abridged behavior method.^ We can go just as far * He would have exactly the same attitude if he were conducting an experiment to show whether an ant would crawl over a pencil laid across the trail or go around it.
° We should prefer to look upon this abbreviated method, where the human subject is told in words, e.g., to equate two stimuli; or to state in words whether a given stimulus is present or absent, etc., as A BEHAVIORISTIC PROGRAM 15 and reach just as dependable results by the longer method as by the abridged. In many cases the direct and typically human method cannot be safely used. Suppose that we doubt the accuracy of the setting of the control instru- ment, in the above experiment, as we very likely do if a defect in vision is suspected. It is hopeless for us to get his introspective report. He will say: " There is no difference in sensation, both are reds, identical in quality. ' ' But suppose we confront him with the standard and the control and so arrange the conditions that he is punished if he responds to the control but not if to the standard. We then interchange the positions of the standard and the control at will and force him to attempt to respond to the one and not to the other. If he can learn to make the adjustment even after a large number of trials it is evident that the two stimuli do afford the basis for a differential response. Such a method may sound nonsensical, but it is believed that we shall have to resort increasingly to just such methods where we have reason to distrust the language method.
There is hardly a problem in human vision which is not also a problem in animal vision: mention may be made of the limits of the spectrum, threshold values, absolute and relative, flicker, Talbot's law, Weber's law, field of vision, the Purkinje phenomenon, etc. Every one can be worked out by behavior methods. Many of them are being worked out at the present time.
All of the work upon the senses can be consistently car- ried forward along the lines we have suggested for vision. Our results will, in the end, give an excellent picture of what each organ stands for in the way of function. The the language method in behavior. It in no way changes the status of experimentation. The method becomes possible merely by virtue of the fact that in the particular case the experimenter and his animal have systems of abbreviated or shorthand behavior signs (language), any one of which may stand for a habit belonging to the repertoire both of the experimenter and his subject. To make the data obtained by the language method virtually the whole of behavior — or to attempt to mold all of the data obtained by other methods in terms of the one which has by all odds the most limited range — is putting the cart before the horse with a vengeance.
16 PSYCHOLOGY AND BEHAVIOR anatomist and the physiologist may take our data and show, on the one hand, the structures which are responsible for these responses, and, on the other, the physico-chemical relations which are necessarily involveci (physiological chemistry of nerve and muscle) in these and other reac- tions.
To the behaviorist's position thus briefly outlined some serious objections are sure to be raised. It may be argued that one might, if he were sufficiently foolhardy, hold such a view if the study of sensory responses were all that is demanded of the psychologist. But, alas, since imagery and affection are also fundamental elements (or processes?) of consciousness, the behaviorist, it is to be regretted, must be handed his passports. Before accepting them let us examine the nature of the supposed mental existences which refuse to listen to the siren voices of the behaviorists.
The image as a form of implicit behavior. — The most serious obstacle in the way of a free passage from struc- turalism to behaviorism is the '' centrally aroused sensa- tion " or '' image." If thoughts go on in terms of centrally aroused sensations, as is maintained by the majority of both structural and functional psychologists, we should have to admit that there is a serious limitation on the side of method in behaviorism. Imagery from Galton on has been the inner stronghold of a psychology based upon introspection. All of the outer defenses might be given over to the enemy, but the cause could never wholly be lost so long as the pass (introspection) to this stronghold (image) could be maintained.
So well guarded is the image that it would seem almost foolhardy for us to make an attack upon it. If we did not perceive certain signs of weakening on the part of the garrison it would seem best to agree with Professor Cattell that the position of the behaviorist is too radical, and that we should better admit the claims of imagery and try to work out a scheme for behaviorism which will embrace the image. Suppose we consider this aspect of the question first: does the inclusion of the image weaken the claims of the behaviorist? It must be admitted that it does.
IMPLICIT BEHAVIOR 17