BoE OT UR. Be ek AN oh TC DT BEHAVIORISM Joun B. Watson Ext oa ot oil eee LIBRARY OF THE THEOLOGICAL SEMINARY PRINCETON, N. J. PRESENTED BY ie eye Nivea ore Ee liee Sec'y Lae” = | Cs f f | Divisionwled Af... | | ; \ ‘ s 4 ee r mae, Secttons. MoM wel eed OO As ee RP Bye am Hare? “uth Tiae pty » Vad At vie oP =l Ni 4 Si) BEHAVIORISM The People’s Institute “Tectures-in-Print” Series PSYCHOLOGY by Everett Dean Martin $3.00 BEHAVIORISM by John B. Watson 7 $3.00 INFLUENCING HUMAN BEHAVIOR by H. A. Overstreet $3.00 INDUSTRIAL PSYCHOLOGY by Charles S. Myers $2.50 THE MEANING OF A LIBERAL EDUCATION by Everett Dean Martin $3.00 MODERN SCIENCE AND PEOPLE’S HEALTH Edited by Benjamin C. Gruenberg $2.50 Other Volumes in Preparation W>W- NORTON & COMPANY, INC. 70 Fifth Avenue New York BEHAVIORISM John B. ‘Watson Formerly Professor of Psychology and Director of the Psychological Laboratory, Johns Hopkins University. Lecturer, The New School for Social Research. : NEW YORK W: W: NORTON & COMPANY, INC. Publishers ~& Copyright —— hese Seale a The People’s Institute Publishing . +, Sen Company, Inc., 1924, 1925. es ee | a gan ; f y - fi S ; £1 ue sey “ iB « | : if ye ; ae ae ; % | ha To STANLEY RESOR Whose unfailing interest in both industry and science has given me the opportunity to write this book. Digitized by the Internet Archive — in 2022 with funding from Princeton Theological Seminary Library https://archive.org/details/behaviorism0Owats _ af ya Preface HILE this volume is written as a series of lectures and in a somewhat free and easy style, every effort has been made to present facts in unmutilated form and to state theoretical positions with accuracy. In approaching subjective psychology for the first time, the reader meets with one great difficulty. He comes in from the world of things—a world which he can manipulate, hold up, examine and change about. When he comes to subjective psychology, he leaves all this behind; he has to face a world of intangibles, a world of definitions, and it takes him weeks to find out what this kind of psychology is about. Rare indeed is the individual who ever thoroughly awakens to the problems discussed in the general text books of introspective psychologies current today. Because behavioristic psychology deals with tangibles, the reader sees no break between his physical, chemical, and biological world and his newly-faced behavioristic world. He may not like the simplicity and severity of Behavior- ism, but he cannot fail to understand Behaviorism if he but gives it a little honest reading, Therefore, the author hopes that this book will offer a happy approach to the whole field of psychology. JoHN B. Watson Malba, Long Island, New York Contents LECTURE hi WHAT IS BEHAVIORISM? > « » « The old and new Psychology contrasted. II. HOW TO STUDY HUMAN BEHAVIOR..... Prob- lems, methods, technique and samples of results, Ut THE HUMAN TBODY? a... 23 What it is made of, how it is put together, and how it works. Part I—The structures that make Behavior possible, IV. THE HUMAN BODY..... What it is made of, how v VII. it is put together, and how it works. Part Il]—The glands in everyday Behavior. ARE THERE ANY HUMAN INSTINCTS? .... Part I—On the subject of talent and tendencies and the inheritance of all so-called ‘mental’ traits. ARE THERE ANY HUMAN INSTINCTS? .... Part II—What the experimental study of the human young teaches us. EMOTIONS. .... What emotions are we born with—how do we acquire new ones—how do we lose our old ones? Part I—A general survey of the field and some experimen- tal studies. WILT EMOTIONS: .e02": What emotions are we born with—how IX. Wy XII. do we acquire new ones—how do we lose our old ones? Part IJ—Further experiments and observations on how we acquire, shift and lose our emotional life. OUR MANUAL HABITS. .... How and when they start, how we retain them, and how we discard them. TALKING AND THINKING. .... Which when rightly understood goes far in breaking down the fiction that there is any such thing as mental life, DO WE ALWAYS THINK IN WORDS ... . Ordoes our whole body do the thinking? PERSONALITY: 2 Presenting the thesis that our personality is but a reflection of the genetic history of our habits. Pace 61 74 87 108 132 159 180 202 216 we CDF int Toten I WHAT IS BEHAVIORISM?P The Old and New Psychology Contrasted BEFORE beginning our study of “behaviorism” or “behavioristic” psy- chology, it will be worth our while to take a few minutes to look at the conventional school of psychology that flourished before the advent of behaviorism in 1912—and that still flourishes. Indeed we should point out at once that behaviorism has not as yet by any means replaced the older psychology—called introspective psychology—ot James, Wundt, Kilpe, Titchener, Angell, Judd, and McDougall. Possibly the easiest way to bring out the contrast between the old psychology and the new is to say that all schools of psychology except that of behaviorism claim that “consciousness” is the subject matter of psychology. Behaviorism, on the contrary, holds that the subject matter of human psychology is the be- havior or activities of the human being. Behaviorism claims that “con- sciousness” is neither a definable nor a usable concept; that it is merely another word for the “soul” of more ancient times. The old psychology is thus dominated by a kind of subtle religious philosophy. The Religious Background of Current Introspective Psychology No one knows just how the idea of a soul or the supernatural started. It probably had its origin in the general laziness of mankind. Certain individuals who in primitive society declined to work with their hands, to go out hunting, to make flints, to dig for roots, became keen observers of human nature. They found that the loud noise from breaking limbs, thunder and other sound-producing phenomena, would throw the primitive individual from his very birth into a panicky state, causing him to stop the chase, to cry, to hide and the like—and that in this state it was easy to train or, more scientifically, to condition him. (I will talk to you about conditioning and conditioned reflexes later on in this lecture and again in the second lec- ture.) These lazy but good observers soon found devices by means of which they could at will throw individuals into this fearsome attitude and thus control primitive human behavior. For example, colored nurses down South have gained control over the young white children by telling them that there is someone ready to grab them in the dark; that when it is thundering there is a fearsome power which they can appease by being 3 4 BEHAVIORISM good boys and girls. The “medicine men” of primitive times soon estab- lished an elaborate control through signs, symbols, rituals, formulae, and the like. Medicine men have always flourished. A good medicine man has the best of everything and, best of all, he doesn’t have to work. These individuals have been variously called medicine men, soothsayers, dream-interpreters and prophets. Skill in bringing about these emotional conditionings of the people increased rapidly ; organization among medicine men took place and we began to have religions of one kind or another, and churches, temples, cathedrals and the like, each presided over by a medicine man. I think an examination of the psychological history of people will show that their behavior has always been easily controlled by fear stimuli. . If the fear element were dropped out of any religion, that religion could not long survive. This fear element (equivalent to the electric shock in establishing conditioned reflexes see p. 21) was variously introduced as the “devil,” “evil,” “sin” and the like. The individual who functions as a medicine man in the narrow family group is, of course, always the father. In the larger group God or Jehovah takes the place of the family father. Thus even the modern child from the beginning is confronted by the dicta of medicine men—be they the father, the soothsayer of the village, the God or Jehovah. Having been brought up in this attitude towards authority, he never questions the concepts imposed upon him. An Example of Such Concepts One example of such a concept is that there is a fearsome God and that every individual has a soul which is separate and distinct from the body. This soul is really a part of the supreme being. This concept has led to the philosophical platform called ‘dualism.” All psychology except behaviorism is dualistic. That is to say we have both a mind (soul) and a body. This dogma has been present in human psychology from earliest antiquity. No one has ever touched a soul, or has seen one in a test tube, or has in any way come into relationship with it as he has with the other objects of his daily experience. Nevertheless, to doubt its exis- tence is to become a heretic and once might possibly even have led to the loss of one’s head. Even today the man holding a public position dare not question it. With the development of the physical sciences which came with the renaissance, a certain release from this stifling soul cloud was obtained. A man could think of astronomy, of the celestial bodies and their motions, of gravitation and the like, without involving soul. Although the early WHAT IS BEHAVIORISM? 5 scientists were as a rule devout Christians, nevertheless they began to leave soul out of their test tubes. Psychology and philosophy, however, in dealing as they thought with non-material objects, found it difficult to escape the language of the church, and hence the concepts of mind and soul come down to the latter part of the nineteenth century. It was the boast of Wundt’s students, in 1879, when the first psychological labora- tory was established, that psychology had at last become a science without a soul. For fifty years we have kept this pseudo-science, exactly as Wundt laid it down. All that Wundt and his students really accomplished was to substitute for the word “soul” the word “consciousness,” An Examination of Consciousness From the time of Wundt on, consciousness becomes the keynote of psychology. It is the keynote of all psychologies today except behavior- ism. It is a plain assumption just as unprovable, just as unapproachable, as the old concept of the soul. And to the behaviorist the two terms are essentially identical, so far as concerns their metaphysical’ implications. To show how unscientific is the concept, look for a moment at William James’ definition of psychology. “Psychology is the description and ex- planation of states of consciousness as such.” Starting with a definition which assumes what he starts out to prove, he escapes his difficulty by an argumentum ad hominem. Consciousness—Oh, yes, everybody must know what this “‘consciousness” is. When we have a sensation of red, a perception, a thought, when we will to do something, or when we purpose to do something, or when we desire to do something, we are being con- scious. All other introspectionists are equally illogical. In other words, they do not tell us what consciousness is, but merely begin to put things into it by assumption; and then when they come to analyze consciousness, naturally they find in it just what they put into it. Consequently, in the analyses of consciousness made by certain of the psychologists you find such elements as sensations and their ghosts, the wages. With others you find not only sensations, but so-called affective elements ; in still others you find such elements as wtll—the so-called conative element in consciousness. With some psychologists you find many hundreds of sensations of a cer- tain type; others maintain that only a few of that type exist. And so it goes. Literally hundreds of thousands of printed pages have been pub- lished on the minute analysis of this intangible something called ‘conscious- ness, And how do we begin work upon it? Not by analyzing it as we would a chemical compound, or the way a plant grows. No, those things are material things. This thing we call consciousness can be analyzed only 6 BEHAVIORISM by introspection—a looking in on what goes on inside of us. As a result of this major assumption that there is such a thing as consciousness and that we can analyze it by introspection, we find as many analyses as there are individual psychologists. There is no way of experimentally attacking and solving psychological problems and standard- izing methods, The Advent of the Behaviorists In 1912 the behaviorists reached the conclusion that they could no longer be content to work with intangibles and unapproachables. They decided either to give up psychology or else to make it a natural science. They saw their brother-scientists making progress in medicine, in chem- istry, in physics. Every new discovery in those fields was of prime im- portance; every new element isolated in one laboratory could be isolated in some other laboratory; each new element was immediately taken up in the warp and woof of science as a whole. May I call your attention to the wireless, to radium, to insulin, to thyroxin, and hundreds of others? Elements so isolated and methods so formulated immediately began to function in human achievement. In his first efforts to get uniformity in subject matter and in methods the behaviorist began his own formulation of the problem of psychology by sweeping aside all mediaeval conceptions. He dropped from his scien- tific vocabulary all subjective terms such as sensation, perception, image, desire, purpose, and even thinking and emotion as they were subjectively defined, The Behaviorist’'s Platform The behaviorist asks: Why don’t we make what we can observe the ' real field of psychology? Let us limit ourselves to things that can be observed, and formulate laws concerning only those things. Now what can we observe? Well, we can observe behavior—what the organism does or says. And let me make this fundamental point at once: that saying is doing—that is, behaving. Speaking overtly or to ourselves (thinking) is just as objective a type of behavior as baseball. The rule, or measuring rod, which the behaviorist puts in front of him always is: Can I describe this bit of behavior I see in terms of “‘stimulus and response’? By stimulus we mean any object in the general environ- ment or any change in the tissues themselves due to the physiological © WHAT IS BEHAVIORISM? 7 condition of the animal, such as the change we get when we keep an ani- mal from sex activity, when we keep it from feeding, when we keep it from building a nest. By response we mean anything the animal does— such as turning towards or away from a light, jumping at a sound, and more highly organized activities such as building a skyscraper, drawing plans, having babies, writing books, and the like. At this point let me diverge to emphasize the fact that almost from infancy society begins to prescribe behavior. A Chinese baby must use chop sticks, eat rice, wear certain kinds of clothes, grow a queue, learn to speak Chinese, sit in a certain kind of way, worship his ancestors, and the like. The American baby must use a fork, learn quickly to form habits of personal cleanliness, wear certain kinds of clothes, learn reading, writ- ing and arithmetic, become monogamous, worship the Christian God, go to church and, yes, even to speak upon a public platform. It is presumably not the function of the behaviorist to discuss whether these things which society prescribes serve as a help or a hindrance to the growth or adjust- ment of an individual. The behaviorist is working under the mandates of society and consequently it does come within his province to say to society: “Tf you decide that the human organism should behave in this way, you must arrange situations of such and such kinds.” I would like to point out here that some time we will have a behavioristic ethics, experimental in type, which will tell us whether it is advisable from the standpoint of present and future adjustments of the individual to have one wife or many wives; to have capital punishment or punishment of any kind; whether prohibition or no prohibition; easy divorces or no divorces; whether many of our other prescribed courses of conduct make for adjustment of the individual or the contrary, such for example as having a family life or even knowing our own fathers and mothers, Some Specific Problems of the Behaviorists You will find, then, the behaviorist working like any other scientist. His sole object is to gather facts about behavior—verify his data—subject them both to logic and to mathematics (the tools of every scientist). He brings the newborn individual into Mis experimental nursery and begins to set problems: What is the baby doing now? What is the stimulus that makes him behave this way? He finds that the stimulus of tickling the cheek brings the response of turning the mouth to the side stimulated. The stimulus of the nipple brings out the sucking response. The stimulus of a rod placed on the palm of the hand brings closure of the hand and the suspension of the whole body by that hand and arm if the rod is raised. 8 BEHAVIORISM Stimulating the infant with a rapidly moving shadow across the eye will not produce blinking until the individual is sixty-five days of age. Stimu- lating the infant with an apple or stick of candy or any other object will not call out attempts at reaching until the baby is around 120 days of age. Stimulating a properly brought up infant at any age with snakes, fish, darkness, burning paper, birds, cats, dogs, monkeys, will not bring out that type of response which we call “fear” (which I would rather call reaction “X”) which is a catching of the breath, a stiffening of the whole body, a turning away of the body from the source of stimulation, a running or crawling away. (See lecture 7.) On the other hand, there are just two things which will call out a fear response, namely, a loud sound, and loss of support. Now the behaviorist finds from observing children brought up outside of his nursery that hundreds of these objects will call out fear responses. Consequently, the scientific question arises: If at birth only two stimuli will call out fear, how do all these other things ever finally come to call it out? Please notice that the question is not a speculative one. It can be answered by experiments, and the experiments can be reproduced and the same findings can be had in every laboratory in the land. Convince your- self of this by making a simple test. If you will take a snake, mouse or dog and show it to a baby who has never seen these objects or been frightened in other ways, he begins to manipulate it, poking at this, that or the other part. Do this for ten days until you are logically certain that the child will always go towards the dog and never run away from it (positive reaction) and that it does not call out a fear response at any time. In contrast to this, pick up a steel bar and strike upon it loudly behind the infant’s head. Immediately the fear re- sponse is called forth. Now try this: At the instant you show him the animal and just as he begins to reach for it, strike the steel bar behind his head. Repeat the experiment three or four times. A new and import- ant change is apparent. The animal now calls out the same response as the steel bar, namely a fear response. We call this, in behavioristic psy- chology, the conditioned emotional response—a form of conditioned reflex. Our studies of conditioned reflexes make it easy for us to account for the child’s fear of the dog on a thoroughly natural science basis without lugging in consciousness or any other so-called mental, process. A dog comes toward the child rapidly, jumps upon him, pushes him down and at the same time barks loudly. Oftentimes one such combined stimulation is all that is necessary to make the baby run away from the dog the moment it comes within his range of vision. WHAT IS BEHAVIORISM? 9 In another lecture I shall show you other conditioned emotional res- ponses, such as those connected with love, where the mother by petting the child, rocking it, stimulating its sex organs in bathing, and the like, calls out the embrace, gurgling and crowing as an unlearned original response. Soon this response becomes conditioned. The mere sight of the mother calls out the same kind of response as actual bodily contacts. I should like to point out that in rage we get a similar set of facts. The stimulus of holding the infant’s moving members brings out the original unlearned response we call rage. Soon the mere sight of a nurse that handles a child badly throws the child into a fit. Thus we see how relatively simple our emotional responses are in the beginning and how terribly complicated home life soon makes them. . In the next lecture we shall develop the idea of conditioned responses in general. We can set up conditioned responses in animals as low in the scale as the amoeba—not necessarily of the same kind as the above, but similar ones. The behaviorist has his problems with the adult as well. What methods shall we use systematically to condition the adult? For example, to teach him business habits, scientific habits? Both manual habits (tech- nique and skill) and laryngeal habits (habits of speech and thought) must be formed and tied together before the task of learning is complete. After these work habits are formed, what system of changing stimuli shall we surround him with in order to keep his level of efficiency high and con- stafitly rising ? In addition to vocational habits, there comes the problem of his emotional life. How much of it is carried over from childhood? What part of it interferes with his present adjustment? How can we make him lose this part of it; that is, uncondition him where unconditioning is nec- essary, and condition him where conditioning is necessary? Indeed we know nothing about the amount and kind of emotional or, better, visceral habits (by this term we mean that our stomach, intestines, breathing, etc. become conditioned—form habits) that should be formed. In one of the later lectures I wish to bring out the fact that visceral habits can be formed, that organization in this field is possible but has hitherto been neglected. Probably more adults in this universe of ours suffer vicissitudes in family life and in business activities because of poor and insufficient visceral habits than through the lack of technique and skill in manual and verbal accomplishments. One of the large problems in big organizations teday is that of personality adjustments. The young men and young 10 BEHAVIORISM women entering business organizations have plenty of skill to do their work but they fail because they do not know how to get along with other people. Does This Behavioristic Approach Leave Anything Out of Psychology? After hearing this brief survey of the behavioristsic approach to the problems of psychology, I can almost hear you exclaiming: “Why, yes, it is worth while to study human behavior in this way, but the study of behavior is not the whole of psychology. It leaves out too much. Don’t I have sensations, perceptions, conceptions? Do I not forget things and remember things, imagine things, have visual images and auditory images of things I once have seen and heard? Can I not see and hear things that I have never seen or heard in nature? Can I not be attentive or inatten- tive? Can I not will to do a thing or will not to do it, as the case may be? Do not certain things arouse pleasure in me, and others displeasure? Be- haviorism is trying to rob us of everything we have believed in since earliest childhood.” Having been brought up on introspective psychology, as most of you have, these questions are perfectly natural and you will find it hard to put away this terminology and begin to formulate your psychological life in terms of behaviorism. Behaviorism is new wine and it will not,go into old bottles; therefore I am going to try to make new bottles out of you. I am going to ask you to put away all of your oid presuppositions and to allay your natural antagonism and accept the behavioristic plat- form at least for this series of lectures. Before they end I hope you will find that you have progressed so far with behaviorism that the questions you now raise will answer themselves in a perfectly satisfac- tory natural science way. Let me hasten to add that if I were to ask you to tell me what you mean by the terms you have been in the habit of using) I could soon make you tongue tied with contradictions. I believe I could even convince you that you do not know what you mean by them. You have been using them uncritically as a part of your social and literary tradition, Let us forget them until later lectures, Io Understand Behaviorism Begin to Observe People This is the fundamental starting point of behaviorism. You will soon find that instead of self-observation being the easiest and most natural way of studying psychology, it is an impossible one; you can observe in yourselves only the most elementary forms of response. You will find, on WHAT IS BEHAVIORISM? 11 the other hand, that when you begin to study what your neighbor is doing, you will rapidly become proficient in giving a reason for his behavior and in setting situations, (presenting stimuli) that will make him behave in a predictable manner. Definition of Behaviorism Definitions are not as popular today as they used to be. The defini- tion of any one science, physics, for example. would necessarily include the definition of all other sciences. And the same is true of behaviorism. About all that. we can do in the way of defining a science at the present time is to mark a ring around that part of the whole of natural science that we claim particularly as our own. | Behaviorism, as you have already grasped from our preliminary dis- cussion, is, then, a natural science that takes the whole field of human adjustments as its own. Its closest scientific companion is physiology. Indeed you may wonder, as we proceed, whether behaviorism can be dif- ferentiated from that science. It is different from physiology only in the grouping of its problems, not in fundamentals or in central viewpoint. Physiology is particularly interested in the functioning of parts of the animal—for example, its digestive system, the circulatory system, the nervous system, the excretory systems, the mechanics of neural and muscu- lar response. Behaviorism, on the other hand, while it is intensely inter- ested in all of the functioning of these parts, is intrinsically interested in what the whole animal will do from morning to night and from night to morning. The interest of the behaviorist in man’s doings is more than the interest of the spectator—he wants to control man’s reactions as physical Scientists want to control and manipulate other natural phenomena. It is the business of behavioristic psychology to be able to predict and to control human activity. To do this it must gather scientific data by experi- mental methods. Only then can the trained behaviorist predict, given the stimulus, what reaction will take place; or, given the reaction, state what the situation or stimulus is that has caused the reaction. Let us look for a moment more closely at the two terms—stimulus and response. What ts a Stumulus? If I suddenly flash a strong light in your eye, your pupil will contract rapidly. If I were suddenly to shut off all light in the room, the pupil 12 BEHAVIORISM would begin to widen. If a pistol shot were suddenly fired in the back part of the room, practically all of you would jump and possibly turn your heads around. If hydrogen sulphide were suddenly released in the room you would begin to hold your noses and possibly even seek to leave the room. If I suddenly made the room very warm, you would begin to un- button your coats and perspire. If I suddenly made it cold, another re- sponse would take place. Again, on the inside of us we have an equally large realm in which stimuli can exert their effect. For example, just before dinner tonight the muscles of your stomach began to contract and expand rhythmically be- cause of the absence of food. As soon as food was eaten those contrac- tions ceased. By swallowing a small balloon and attaching it to a record- ing instrument we can easily register the response of the stomach to lack of food and note the lack of response when food is present. In the male, at any rate, the pressure of certain fluids (semen) may lead to sex activity. In the case of the female possibly the presence of certain chemical bodies can lead in a similar way to overt sex behavior. The muscles of our arms and legs and trunk are not only subject to stimuli coming from the blood, they are also stimulated by their own responses—that is, the muscle is under constant tension; any increase in that tension, as when a movement is made, gives rise to a stimulus which leads to another response in that same muscle or in one in some distant part of the body; any decrease in that tension, as when the muscle is relaxed, similarly gives rise to a stimu- lus. So we see that the organism is constantly assailed by stimuli—which come through the eye, the ear, the nose and the mouth—the so-called objects of our environment; at the same time the inside of our body is like- wise assailed at every movement by stimuli arising from changes in the tissues themselves. Don’t get the idea, please, that the inside of your body is any different or any more mysterious than the outside of your body. Through the process of evolution human beings have put on sense organs—specialized areas where special types of stimuli are most effective —such as the eye, the ear, the nose, the tongue, the skin and semi-circular ceanalst, To these must be added the whole muscular system, both the striped muscles and the unstriped muscles. The muscles are thus not only organs of response—they are sense organs as well. You will see as we proceed with the lectures that the last two systems play a tremendous role 1 In my third lecture I will tell you how sense organs are made wp and what their general relation is to the rest of the body. er WHAT IS BEHAVIORISM? 13 in the behavior of the human being. Many of our most intimate and personal reactions are due to stimuli set up by tissue changes in our striped muscles and in our viscera, How Training Ever Enlarges the Range of Stimuli to Which We Respond One of the problems of behaviorism is what might be called the ever increasing range of stimuli to which an individual responds. In- deed so marked is this that you might be tempted at first sight to doubt the formulation we gave above, namely that response can be predicted. If you will watch the growth and development of behavior in the human being, you will find that while a great many stimuli will produce a response in the new-born, many other stimuli will not. At any rate they do not call out the same response they later call out. For example, you don’t get very far by showing a new-born infant a crayon, a piece of paper, or the printed score of a Beethoven symphony. In other words, habit formation has to come in before certain stimuli can become effective. Later I shall take up with you the procedure by means of which we can get stimuli which do not ordinarily call out responses to call them out. The general term we use to describe this is “conditioning.” Conditioned responses will be more fully gone into in the next lecture. it is due to conditioning from earliest childhood on that the problem of the behaviorist in predicting what a given response will be is so diffi- cult. The sight of a horse does not ordinarily produce the fear response, and yet there is one person here tonight who will walk a block to avoid coming near to a horse. While the study of behaviorism will never enable its students to look at you and predict that such a state of affairs exists, nevertheless if the behaviorist sees that reaction taking place, it is very easy for him to state approximately what the situation was in the early experience of such a one that brought about this unusual type of adult response. After all, though, we have proceeded upon this practical basis since the time of Adam, What Does the Behaviorist Mean by Response? We have already brought out the fact that from birth to death the organism is being assailed by stimuli on the outside of the body and by stimuli arising in the body itself. Now the organism does something when it is assailed by stimuli. It responds. It moves. The response may be so slight that it can be observed only by the use of instruments. The response may confine itself merely to a change in respiration, or to an in- 14 BEHAVIORISM crease or decrease in blood pressure. It may call out merely a movement of the eye. The more commonly observed responses, however, are move- ments of the whole body, movements of the arm, leg, trunk, or combina- tions of all the moving parts. Usually the response that the organism makes to a stimulus brings about an adjustment, though not always. By an adjustment we mean merely that the organism by moving so alters its physiological state that the stimulus no longer arouses reaction. This may sound a bit complicated, but examples will clear it up. If I am hungry, stomach contractions begin to drive me ceaselessly to and fro. If, in these restless seeking movements, I spy apples on a tree, I immediately climb the tree and pluck the apples and begin to eat. When surfeited, the stomach contractions cease. Al- though there are apples still hanging round about me, I no longer pluck and eat them. Again, the cold air stimulates me. I move around about until I am out of the wind. In the open I may even dig a hole. Having escaped the wind, it no longer stimulates me to further action. Under sex excitement the male may go to any length to capture a willing female. Once sex activity has been completed the restless seeking movements dis- appear. The female no longer stimulates the male to sex activity. The behaviorist has often been criticized for this emphasis upon response. Some psychologists seem to have the notion that the behaviorist is interested only in the recording of minute muscular responses. Nothing could be further from the truth, Let me emphasize again that the be- haviorist is primarily interested in the behavior of the whole man. From morning to night he watches him perform his daily round of duties. If it is brick-laying, he would like to measure the number of bricks he can lay under different conditions, how long he can go without dropping from fatigue, how long it takes him to learn his trade, whether we can improve his efficiency or get him to do the same amount of work in a less period of time. In other words, the response the behaviorist is interested in is the commonsense answer to the question “what is he doing and why is he doing it?’ Surely with this as a general statement, no one can distort the the behaviorist’s platform to such an extent that it can be claimed that the behaviorist is merely a muscle physiologist. The behaviorist claims that there is a response to every effective stimulus and that the response is immediate. By effective stimulus we mean that it must be strong enough to overcome the normal resistance to the passage of the sensory impulse from sense organs to muscles. Don’t get confused at this point by what the psychologist and the psycho-analyst sometimes tell you. If you read their statements, you are likely to believe WHAT IS BEHAVIORISM? 15 that the stimulus can be applied today and produce its effect maybe the next day, maybe within the next few months, or years. The behaviorist doesn’t believe in any such mythological conception. It is true that I can give the verbal stimulus to you “Meet me at the Belmont tomorrow for lunch at one o’clock.” Your immediate response is “All right, I’ll be there.” Now what happens after that? We will not cross this difficult bridge now but may I point out that we have in our verbal habits a mech- anism by means of which the stimulus is reapplied from moment to mo- ment until the final reaction occurs, namely going to the Belmont at one o’clock the next day. General Classification of Response The two commonsense classifications of response are “external” and “internal”—or possibly the terms “overt” (explicit) and “implicit” are better. By external or overt responses we mean the ordinary doings of the human being—he stoops to pick up a tennis ball, he writes a letter, he enters an automobile and starts driving, he digs a hole in the ground, he sits down to write a lecture, or dances, or flirts with a woman, or makes love to his wife. We do not need instruments to make these observations. On the other hand, responses may be wholly confined to the muscular and glandular systems inside the body. A child or hungry adult may be stand- ing stock still in front of a window filled with pastry. Your first exclama- tion may be “he isn’t doing anything” or “he is just looking at the pastry.” An instrument would show that his salivary glands are pouring out se- cretions, that his stomach is rhythmically contracting and expanding, and that marked changes in blood pressure are taking place—that the endo- crine glands are pouring substances into the blood. The internal or im- plicit responses are difficult to observe, not because they are inherently different from the external or overt responses, but merely because they are hidden from the eye. Another general classification is that of learned and unlearned re- sponses. I brought out the fact a little while ago that the range of stimuli to which we react is ever increasing. The behaviorist has found by his study that most of the things we see the adult doing are really learned. We used to think that a lot of them were instinctive, that is “unlearned.” But we are now almost at! the point of throwing away the word “instinct.” Still there are a lot of things we do that we do not have to learn—to per- spire, to breathe, to have our heart beat, to have digestion take place, to have our eyes turn toward a source of light, to have our pupils contract, to show a fear response when a loud sound is given. Let us keep as our 16 BEHAVIORISM y second classification then “learned responses,’ and make it include all of our complicated habits and all of our conditioned responses; and “‘un- learned” responses, and mean by that all of the things that we do in earliest infancy before the processes of conditioning and habit formation get the upper hand. Another purely logical way to classify responses is to designate them by the sense organ which initiates them. We could thus have a visual unlearned response—for example, the turning of the eye of the youngster at birth toward a source of light. Contrast this with a visual learned response, the response, for example, to a printed score of music or a word. Again, we could have a kinaesthetic' unlearned response when the infant reacts by crying to a long-sustained twisted position of the arm. We could have a kinaesthetic learned response when we manipulate a delicate object in the dark or, for example, tread a tortuous maze. Again, we can have a visceral unlearned response where pressure of the urine produces an erection in the male. Contrast this with the learned or visceral condi- tioned response where the sight of a certain female or even the sound of her voice or the perfume that she usually wears will produce an erection. This discussion of stimulus and response shows what material we have to work with in behavioristic psychology and why behavioristic psy- chology has as its goal to be able, given the stimulus, to predict the re- sponse—or, seeing the reaction take place to state what the stimulus is that has called out the reaction, Is Behaviorism Merely a Methodological Approach to the Study of Psychological Problems, or is it an Actual System of Psychology? If psychology can do without the terms “mind” and “consciousness,” indeed if it can find no objective evidence for their existence, what is going to become of philosophy and the so-called social sciences which today are built around the concept of mind and consciousness? Almost every day the behaviorist is asked this question, sometimes in a friendly inquiring way, and sometimes not so kindly. While behaviorism was fighting for its existence it was afraid to answer this question. Its con- tentions were too new; its field too unworked for it to allow itself even to think that some day it might be able to stand up and to tell philosophy and the social sciences that they, too, must scrutinize anew their own premises. 1 By kinaesthetic we mean the muscle sense. Our muscles are supplied with sensory nerve endings. When we move the muscles these sensory nerve endings are stimulated, Thus, the stimulus to the kinaesthetic or muscle sense is a movement of the muscle tself. WHAT IS BEHAVIORISM? 17 Hence the behaviorist’s one answer when approached in this way was to say, “I can’t let myself worry about such questions now. Behaviorism is at present a satisfactory way of going at the solution of psychological problems—it is really a methodological approach to psychological prob- lems.” Today behaviorism is strongly entrenched. It finds its way of going at the study of psychological problems and its formulation of those problems growing more and more adequate. Today the behaviorist can safely throw out a real challenge to the subjective psychologists—‘Show us that you have a possible method, indeed that you have even a legitimate subject matter. Prove to us that philosophy and the social sciences based upon your speculations have any right to further take up the time and thought of developing students.” The past ten years have seen a growing tendency—but one combatted at every point by the old line philosopher—on the part of the “mental sciences” to crawl over the stone wall that separates them from behavior- ism. Let me put all of these “sciences” based upon the concept of mind on the left hand side of a vertical line; on the right hand side of the line I shall show you their present trend: Up to the Advent of Behaviorism Now Showing the Following Dominated by Concept of Leanings: Consciousness: Introspective psychology. Behaviorism. Functional psychology. Philosophy. Gradually disappearing and become ing the history of science. Ethics. Experimental ethics based entirely upon behavioristic methods. . : Rapidly becoming a _behavioristic peau SyCHOLOEY study of how groups—family, vil- lage, national, church and the like— build up habits (attitudes) in the individual during the formative period and thus maintain control of him throughout life. Sociology. Merging into behavioristic social psychology and into economics. 18 BEHAVIORISM Up to the Advent of Behaviorism Dominated by Concept of Consciousness : Religion. Psycho-Analysis (Based largely upon religion, intro- spective psychology, and Voodoo- ism, Now Showing the Following Leanings : Being replaced among the educated’ by experimental ethics. Being replaced slowly by behavior- istic studies on the human child where scientific methods are being established for conditioning and un- conditioning the child. When such studies are carried to an ideal state, there should be no reason for psy- chopathic breakdowns or disturb- ances in the adult. While this discussion does not completely answer the question whether behaviorism is a system or a method, nevertheless it does show that be- havioristic formulations are becoming central in the whole field of what has hitherto been called ‘“‘the mental and moral sciences.” I hope in the remaining lectures to show you why behavioristic formu- lations and methods are an adequate way of accounting for all psycho- logical problems. Il HOW TO STUDY HUMAN BEHAVIOR Problems, Methods, Technique, and Samples of Results Analyzing Psychological Problems Our last lecture touched many things lightly. From now on we must prepare ourselves for more strenuous undertakings. In that lecture we found that the behaviorist is constantly working with stimuli whose effect on the human organism is unknown. He seeks to find out what kind of reaction they will call forth when presented singly or in combination. He varies not only the combination in which they are presented but their in- tensity and the length of time they are allowed to exert their effect. For example, a mother is sleeping in a chair in front of me. I speak to her but my voice does not call out a response. I make my dog bark gently out in the yard; that likewise fails to call out a response. Then I go to the sleeping room of her youngest child and cause it to cry. Im- mediately the mother springs from the chair and runs to the child’s room. _I next determine scientifically how strong the cry must be and the length of time it must endure before the response is called out. I next vary conditions, then I work with many other mothers; I apply mathematics and logic to my results. This would be scientific procedure. But from a commonsense point of view the whole result is expressed by the old famil- lar saying—‘the slightest cry of her infant wakes a sleeping mother.” Another example. My Airedale dog lies asleep at my feet. What will happen if I rustle the paper? Only a change in respiration. If I throw down a small note book? It causes a change in respiration—a quickened pulse and a slight movement of the tail and foot. I get up without touching him—immediately the dog springs up ready to play, fight or eat. Now the human race has been in existence for many hundreds of thousands of years; during that time (even though at times we have followed the false psychological god Introspection) we have succeeded in gathering a lot of data on the effect various stimuli have upon human behavior. Possibly you may think I am choosing pretty artificial illustrations— you may maintain that we never play with situations and stimuli as I have 19 20 BEHAVIORISM here suggested. Go then to real life. We increase our employees’ salaries. We offer a bonus—we offer them homes at nominal rental so they can get married. We put in baths—playgrounds. We are constantly manipu- lating stimuli, dangling this, that and the other combinations in front of the human being in order to determine the reactions they will bring forth —hoping that the reaction will be “in line with progress”, “desirable”, “sood”. (And society really means by “desirable”, “good”, “in line with progress”, reactions that will not disturb its recognized and established traditional order of things.) Sometimes, on the other hand, the behaviorist (and I am now going to admit that we are all behaviorists—we have to be) works the other way round. The individual is doing something—reacting—behaving. The behaviorist, to make his methods socially effective, to be able to reproduce this reaction at another time (and possibly in other individuals as well) attempts to determine what the situation is that causes this particular reaction, I see some of you yawning and fighting sleep in this crowded room. IT see the same behavior every night after we have been together for about one half hour. Why? Some of you may say that it is a stupid lecture—some that the ventilation is bad—and if they are scientifically inclined they may even elaborate by saying “You see, in a crowded room like this the oxygen is used up rapidly—this causes an excess of carbon dioxide in the air we breathe; carbon dioxide is bad for you—it makes you yawny and sleepy and if the tension gets very high it may even kill you.” But suppose I am not satisfied and begin to experiment? We have actually made such experiments but I will not take time now to tell you about them—I’ll just give you the result. You yawn and grow sleepy because of the increasing heat around your body—especially in the un- stirred air spaces between your skin and clothing. If the janitor would put in two or three fans to keep the air stirred up, your yawning and sleepiness would disappear—the slightly increased CO, tension while it is a fact, has nothing to do with the reaction. Scientific method has en- abled us not only to find the stimulus causing the reaction but also how effectively to control the reaction by removing or modifying the stimulus. General Formulation We have gone far enough for you to see that we can throw our psy- chological problems and their solutions into terms of stimulus and response. Let us use the abbreviations S for stimulus (or the more complex situa- HOW TO STUDY HUMAN BEHAVIOR 21 tion) and R for response. We may schematise our psychological problems as follows: RS FAL lad hatan ts ad sedan UNAM ech R Given ?(to be determined) Ro adh be LAE Ad oe Mees atias de ona banirratsbea? Seb ee DS kg al R ?(to be determined) given Your problem reaches its explanation always when: NS einbas Sohal ssl Fo ea neat ed NE TRL AN R has been determined has been determined Substitution of stimuli or conditioning of stimuli So far our method has been stated very simply. I have led you to believe that the stimulus necessary to call out the reaction exists some- where as a kind of entity only waiting to be found and presented to your subject. I have talked, too, as though the reaction were a fixed kind of thing or entity ready to be called out the moment the organism is stimu- lated appropriately. A little observation shows that our formulation is in- exact and in need of modification. I pointed out in the last lecture that some stimuli when first applied seem to exert no marked effect and certainly not the effect they come later to exert. Let us illustrate this by going back to our formula. Suppose for example we take an already established (unlearned) reaction with both stimulus and response known, such as: Electric shock Withdrawal of hand Now the mere visual stimulus of a patch of red light will not cause the withdrawal of the hand. The patch of red light may produce no marked reaction whatsoever (what reaction does appear will depend upon previous conditioning). Butif I show the red light and then immediately or shortly thereafter stimulate my subject’s hand with the electric current and repeat this routine often enough, the red light will cause the immediate with- drawal of the hand. The red light now becomes a substitute stimulus—it will call out the R whenever it stimulates the subject in that setting. Some- thing has happened to bring about this change. This change, as we have pointed out, is called conditioning—the reaction remains the same but we have increased the number of stimuli that will call it out. To express the new state of affairs we (rather inaccurately) describe the change by ce BEHAVIORISM speaking of the stimulus as being “conditioned.” Please remember, though, that when we speak both of conditioned stimuli and of conditioned re- sponses, we mean that what is conditioned is the whole organism. Contrasted with a conditioned stimulus we have the unconditioned. Certain stimuli from birth will call out definite responses. A few exam- ples of unconditioned stimuli are as follows: ae AA ENN OR ACER INS SM A eae R Light Closing pupil, turning eyes Tapping tendon below knee Kickup of leg (Patellar reflex ) Acid in the mouth Salivary secretion Pricking, burning and Withdrawal of body, crying, cutting skin screaming, etc Observations on infants show quickly that while there are thousands of unconditioned stimuli, they are relatively few when contrasted with the conditioned. Conditioned stimuli are legion in number. Every one of the printed and written 15,000 words that a well educated individual can respond to in an organized way must be looked upon as an example of a conditioned stimulus. Each tool that we work with, each person that we respond to are equally good examples. The total number of con- ditioned and unconditioned stimuli to which we can respond has never been determined. The importance of stimulus substitution or stimulus conditioning cannot be overrated. It enormously widens the range of things that will bring out responses. So far as we know now (actual experimental evi- dence is lacking) we can take any stimulus calling out a standard reaction and substitute another stimulus for it, Let us go back to our general formula for a moment: It is obvious that when we determine S we must now tell whether it is a U (unconditioned) stimulus or a C (conditioned) stimulus. Experiment teaches us as is shown in the above table that a drop of acid in the mouth will from birth produce a flow of saliva. This is an example of a native or unconditioned stimulus. The sight of the smoking hot cherry pie that causes the salivary glands to flow so fully is an example of a conditioned visual stimulus. The sound of the gentle footsteps of the mother that stops the crying of her child is an example of a conditioned auditory stimulus. HOW TO STUDY HUMAN BEHAVIOR 23 Substitution of Response Can we substitute or condition responses? Experiment teaches us that the process of response substitution or conditioning does take place in all animals throughout life. Yesterday his puppy called out from a two-year-old child—fondling, pet words, play and laughter: pa PALS Rn AAP olin arena as tak ALAR 2 a ata R Sight of dog Manipulation, laughter, etc. Today the dog calls out: tS pst dean d nh Managed ended eb coal SAME MED css R Sight of dog Screaming, withdrawal of body, Something happened. Late yesterday the dog bit him too hard in play— broke the skin and caused bleeding. We know that Cutting, burning of skin withdrawal of body, etc. screaming, etc. In other words while the visual stimulus dog has remained substantially the same, the reaction belonging to another unconditioned stimulus (cut- ting, pricking skin) has made its appearance.* The conditioning of responses is just as important as the conditioning of stimuli. It possibly has even greater social bearing. Many of us are surrounded by fixed unchangeable situations such as the kind of home we live in, parents who must be petted and handled gently, wives “who do not understand,” sex hungers from which there is no escaping (for example, marriage to an invalid or insane husband or wife), malformations of the body (permanent inferiorities), and the like. The reactions that we now make to these permanent stimuli are often abortive, inadequate for adjustment; they wreck our constitutions and may make us psychopathic. The fact that different reactions can be conditioned—Adolph Meyer calls them “substitutive”’ reactions—gives us a real hope for future generations if not for our own. ‘This process is sometimes called “sublimation.” Whether conditioned, substituted or sublimated activity is just as adequate for permanent adjustment as the unconditioned has not yet been completely physiologically grounded. 1 From a laboratory standpoint there is ultimately no fundamental difference between a condi: tioned stimulus and a conditioned response. 24 BEHAVIORISM Judging from the lack of permanence of many of the “cures” of the psycho-analyst, one is inclined to think that substitutive reactions, in the realm of sex at any rate, will not remain adequate for the organism. Can We Make or Build in Totally New Responses? Certainly no structurally new pathways are found in the brain after infancy. Neural connections are largely laid down at birth. Yet the num- ber of unconditioned, unlearned responses is too small to care for the adult. May I call your attention, though, to the fact that there are thousands of simple unlearned and unconditioned responses, such as finger and arm movemerits, eye movements, toe and leg movements, that escape the notice of all but trained observers. These are the elements out of which our organized, learned, responses must be formed and apparently by the process of conditioning. These simple, unconditioned, embryological responses, by the presentation of appropriate stimuli (society does this for us), can be grouped and tied together into complex conditioned responses, or habits, such as tennis, fencing, shoe-making, mother reactions, religious reactions, and the like. These complex responses are thus integrations. The organ- ism starts out life with more unit responses than it needs. Relatively few of its vast resources, numerous as its organized complicated acts seem to be, are ever utilized. For examples of unconditioned but diffuse and widespread groups of responses to a stimulus changing over into a circumscribed group of conditioned responses (or habits) let us go to the white rat. It has been without food for 24 hours. I put food in a wire problem box opened by raising an old-fashioned wooden latch. The rat has never been in this situation before. By hypothesis we will assume that all of its first reactions are native and unlearned (which is of course not the case). What does it do? It runs round and round, bites at the wire, pokes its nose between meshes, pulls cage toward it, sticks claws into moving door, raises head and smells about the cage. Notice that every part reaction necessary to the solution of the problem has been many times displayed. These part- reactions are present in its repertoire of unconditioned or unlearned acts. They are (1) walking or running to the door, (2) raising the head (which if done at a given point will result in knocking the latch up), (3) pulling at the moving door with the claws, (4) climbing over the sill to the food. Out of the rat’s vast display of unconditioned responses only 4 are needed -—if given time it will always accidentally stumble upon the solution. But to solve the problem efficiently these 4 part reactions must be spaced and timed—patterned or integrated. When integration, patterning or con- HOW, TO STUDY HUMAN BEHAVIOR 25 ditioning is complete, all other responses except 1-2-3-4 disappear. We would correctly speak of this 1-2-3-4 response as being a new and con- ditioned response. We usually call this process the formation of a habit. Most of you have studied habit formation and at least think you know a great deal about it. But even if you knew all of the existing data about it you could hardly construct a tenable theory of how habits are formed. Both introspectionists and behaviorists have worked en masse, so to speak, in this field in order to settle various questions of fact—such as the factors making for rapidity of habit formation, accuracy of habits, permanence of habits, effects of age on habit formation; the effect of forming two or more habits simultaneously; the transfer of habits and the like. But no experimenter has yet set his experimental problems in such a way as to construct from his data a guiding theory of habit formation. Even today the relationship between what is generally called habit formation and the conditioning of stimuli and of responses has not been worked out. Personally I think there is little new in habit formation, but I may be over-simplifying it. When we are teaching the animal or human to go to a red light and not to a green, or to stay on the true pathway and out of the culs-de-sac, or to open the problem box above described, I think we are merely establishing a conditioned response—the stimulus remains constant. We work to get a “new” or conditioned reaction. When, however, there is social or experimental need to keep the reaction constant but to change the stimulus, as happens when an individual for long periods makes love reactions to a certain female who will have none of him (thereby possibly endangering his whole life structure) there is need for stimulus substitution (“transfer,” the psycho-analysts call it). If the substitution takes place we have an example of a conditioned stimulus. While our studies on the formation of habits in both the human and animal realms have lacked theoretical guidance, nevertheless much informa- tion valuable for psychology has been obtained from them. Indeed the prosecution of work on “habit formation” can be said to have been the chief business of the psychologist until the very recent introduction of con- ditioned reflex methods. This is causing a re-envisagement of the whole problem and the rearrangement of our whole experimental program. We shall postpone further discussion of “habit formation” proper until a later lecture and continue here with experimental work done on “conditioned reflexes.”’ You will notice that most of the experimental work concerns itself really with stimulus substitutions and not with reaction 26 BEHAVIORISM substitutions. There has been relatively little experimental work done upon reaction substitutions. Much of the practical work of the psychia- trists and of the analysts has been of this character. If time permitted I should like to discuss this phase of our problem more at length. Inhibi- tion of response (by conditioning) is another problem of equal importance. This, likewise, we shall have to neglect. Conditioned Reflex Methods Stimulus Substitution in Glandular Reactions Laboratory studies on stimulus substitution have progressed further in the animal field than in the human field. It may be worth your while to review with me some of the work on the dog. Conditioned reflex work began upon the dog and the experimental exactness of the method can there best be demonstrated. The Russian physiologist, Pavlov, and his students have been chiefly responsible for this work. Please recall for a moment that there are two different sets of tissue with which we can respond: 1, our glands; and 2, our muscles (and there are really two kinds of muscles, striped and visceral). The gland usually selected for experimentation is the salivary gland. According to Dr. G. V. Anrep, a former pupil of Pavlov, the salivary gland is a simple organ, not a composite one like the muscular, system of the body. It is far more independent too of the body than is the muscular system, and the activity of the gland can be graduated with greater ease than can muscular action. The fundamental or unconditioned stimulus, as we have stated be- fore, calling out a salivary response is some food or acid substance intro- duced into the mouth: Food, acid Salivary flow The problem now is to take some other stimulus that does not call out a salivary flow—indeed it may not call out any marked general response from the dog—and get it to call out the salivary response. Experiment shows that visual stimuli, such as colored discs, geometrical forms, simple noises, pure tones, bodily contacts, will not call out the salivary response. Any one of them can, however, be made to. A simple operation is first performed on the dog by making a permanent fistula of the parotid duct— that is, a small opening is made to lead from the gland to the external HOW TO STUDY HUMAN BEHAVIOR ah surface of the cheek and a small tube is cemented to this outlet. The drops of saliva coming from the gland now pass out through an external tube instead of into the mouth. This tube is made to connect with an apparatus which records automatically the number of drops that flow from the gland. The animal is isolated from the experimenter and from any auditory, olfactory, visual or other stimuli not controlled by the investi- gator. The application of both the unconditioned and the conditioned stimuli is performed automatically from outside the animal room. The animal is viewed by means of a periscope. It is found that we may substitute for food or acid any stimulus at will and get the salivary response, provided we apply this stimulus (C) simultaneously with the food or acid stimulus (U) ; indeed we may even apply the C stimulus before the U stimulus. Apparently, however, if the U stimulus is given first, the conditioning does not take place. For example, Krestovnikov worked for a year giving the U stimulus first and applying the C stimulus only a few seconds later without ever establishing the reaction. When the C stimulus precedes the U stimulus the conditioning takes place after about 20 to 30 combined applications. The time interval between the application of C before the beginning of U may be varied from a few seconds up to five or more minutes. Suppose in a given case we wish to make a tactual stimulation call out a salivary response. We stimulate the animal tactually for 4 sec- onds on one spot on the left thigh and then apply after a pause of 4 or 5 seconds the unconditioned stimulus, powdered meat and dog biscuit (U). We continue this routine for approximately two months, giving from four to ten stimulations a day with a pause of from 7 to 45 minutes after each. By this time the stimulus substitution will be complete and the tactual stimulus (C) will yield the same number of drops of saliva as the powdered meat and dog biscuit (U). By this simple procedure we have widened the range of stimuli to which the dog can react in a definite way. Instead of our formula above, it now should read: RS Ady es al NA dal Mata a ARN eR ULL A Sa Uh R Powdered meat and dog biscuit For example, 60 drops or of saliva in 30 seconds Tactual stimulus on the left thigh each equal to 0.01 c.c, We have here an example of a complete stimulus substitution. The magnitude of the reaction following upon the conditioned stimulus is the 28 BEHAVIORISM same as that called out by the unconditioned—within the limits of experi- mental error. By this simple procedure we can test out the whole range of stimuli to which an animal can respond. For example, suppose we have so con- ditioned an animal that light of any wave length brings out the salivary response. After conditioning it we next try to find out whether it is sensitive to wave lengths shorter than those that affect the human eye. We start in with green light from the spectrum and gradually increase the wave length of the stimulus light until the reaction fails. This gives the animal’s range in the longer wave lengths. Again we build up the reaction to the green light, then gradually shorten the wave length until the reaction breaks down. This gives us its range in the shorter wave lengths. We can work in the same way on the auditory side. It has been found by certain investigators that the dog will react to tones far higher in pitch frequency of vibration) than can the human being. Man and the dog have never been tested under identical conditions, however. Differential Glandular Responses With a slightly different procedure we can establish so-called differ- ential responses. Suppose, for example, we have conditioned the dog to a given tone A, until tone A calls out the salivary response just as does the powdered meat. Almost any other tone B will at first call out the salivary response (irradiation). Can we so change and build up the dog’s reaction system that he will not react to B but only to A? Yes, within the limits of the dog’s ability to respond to differences in pitch (which is somewhat in doubt). Anrep claims differential response to very slight difference in pitch. Johnson, working by another method, finds no differ- ential response to pitch differences. When working with differential re- actions to tonal stimuli, for example, we proceed to “fix” or circumscribe the stimulus A more narrowly by feeding each time A is sounded but never feeding when B is sounded. Very soon A will call forth the full secretion of saliva whereas B will not call out any secretion at all. This method is equally applicable in every sense field We can return accurate answers to the questions: How accurately can the dog react to noises, to differences in wave length, to odors, etc.? Some of the general facts summarized by Anrep, coming from the study of the salivary reflexes in dogs, may be enumerated as follows: 1. The conditioned responses, like all other habits, are more or less tem- HOW TO STUDY HUMAN BEHAVIOR 29 porary and unstable. After periods of no practice they cease to work; they break down. They can, however, be quickly reestablished. In one observed case in the salivary reflex of the dog a test was made after 2 years. The conditioned reflex was present but not invariable. After one reinforcement it was completely renewed. 2. The substituted stimulus can be fixed and made specific. No other stimulus of its class will then call out the reflex. If you condition the dog to a metronome no other noise will call out the response. 3. The magnitude of the response is dependent upon the strength of the stimulus. Increase the stimulus and there is an increase in the re- sponse. Again, if a continuous stimulus—say a noise or a tone—is interrupted, it has the same effect as strengthening the stimulus—an increased magnitude of response will appear. 4, There is a marked summation effect. If a dog is conditioned separ- ately to sound and to color, there is a marked increase in the number of drops if the stimuli are given simultaneously. 5. Conditioned responses can be “extinguished.” Lack of practice ex- tinguishes them. They can be extinguished by very rapid repetition of the stimulus. “Fatigue” is not the cause of their being extin- guished: in the case of a dog conditioned separately to sound and to color, if the visual stimulus is extinguished the auditory stimulus will call out the response in full force, Stimulus Substitution in Human Salivary Reactions I pointed out to you that to work on salivary responses in dogs a simple operation has to be performed. This is, of course, not possible in the case of human beings (except in cases of accident). Dr. K. S, Lash- ley, however, has perfected a small instrument which serves the same pur- pose. It consists of a small silver disc about the diameter of a 5-cent piece and about 1” thick, grooved on one surface so as to form two non- communicating chambers. Each chamber has a tiny silver tube leading out from it. The central chamber is placed over the tiny opening where the gland comes to the inner surface of the cheek. The tube leading from this chamber conducts the saliva outside the mouth to a recording appa- ratus. The tube from the other chamber leads over to a little aspirator that creates a partial vacuum in this chamber. This serves to make the whole disc cling tightly to the inner surface of the cheek. The whole apparatus, called a sialometer, is more comfortable than my description would seem to warrant. One can eat and sleep with it in place. 30 BEHAVIORISM As in the case of the dog, food substances or acids (U) will call out a salivary response: Food, acid Secretion of salivary fluid In humans as well as in dogs stimulus substitutions can be made. The visual stimulus of a medicine dropper will not at first call out a salivary flow—but if the subject watches you dip the pipette into a solution of acid and then apply this acid to his tongue, the sight of the pipette soon comes to call out the salivary flow. Now we have: OI a Ea cS oa Mia Oe AN lA R Food, acid or Salivary flow Sight of pipette We have thus conditioned our subject. Here too, we have in the human widened the range of stimuli that will call out a salivary response. I have not the time tonight to go into all the work which has been done upon the human salivary gland. Conditioning takes place apparent- ly on a considerable scale throughout life—the watering of the mouth of the child or the adult at the sight of savory viands is a good example. Until experimental tests are made these conditioned responses cannot be observed. There is no question of “association of ideas’’-—the subject cannot “introspect about them”; he cannot even tell you whether they are present or not. May I in passing call your attention to the fact that this gland is not under so-called “voluntary” control—that is, that you can’t “will” to make it secrete or will” to make it stop secreting? Can Other Glands Be Conditioned? We certainly know from the work of Pavlov and his students that the glands of the stomach and other visceral glands can be conditioned just as are the salivary glands. Others have shown that glands in the stomach and other visceral glands can also be conditioned in the human being. We have no experimental work on stimulus substitution in other duct glands. We have reason to believe that urination and the orgasm in the male can be conditioned, but here we are probably dealing with muscular condition- ing which is discussed on page 32. The one other duct gland easily accessible to experimentation (but 6o far as I know yet unexperimented upon) is the tear gland. Probably HOW TO STUDY HUMAN BEHAVIOR 31 many of the tears of the infant—of the hardened theatre fan—of the criminal, and the malingering invalid are true examples of conditioning. The glands of the skin may also offer interesting experimental possibili- ties. Whether the ductless glands such as the thyroid, adrenal, pineal and others can be conditioned is unknown. But emotional reactions can be con- ditioned—and here the whole body is involved. If this is the case, ap- parently the ductless glands have to follow suit and play their own role. We have fair evidence that this is the case. In conditioned emotional reactions both adrenals and thyroids apparently do change their rhythm of functioning, Stimulus Substitution In Striped and Unstriped Motor Reactions. In Striped Muscle Reactions Bechterew, another Russian physiologist, and his students have taught us that stimuli calling out striped muscular responses of arms, legs, trunk, fingers, etc., similarly can be substituted for. One of the simplest ways to bring about an unconditioned response by an unconditioned stimulus is to use a cutting, bruising stimulus. The electric shock is a convenient one. Our formula would read originally ; Se aun Ve Aaa Bae I TE Oh. Urata UY R Cutting, bruising, burning, Withdrawal of arm, electric shock leg, finger If the foot rests upon an electric grill the foot will be jerked up each time _ the current is turned on. We can record on a smoked drum this jump of the leg. We can likewise record each time the electric shock is given. Now, early in this lecture I pointed out that ordinary visual and auditory objects do not call out this sudden reflex withdrawal of the foot. The noise of an ordinary electric buzzer for example will not. But stimulate the subject jointly with the buzzer and electro-tactually 24-30 times (more in some subjects) and the buzzer alone will call out the with- drawal of the foot. Here again we have widened the range of situations that will call out this response. Our formula now reads: Seine ae ce Salvtek Ne Aare seen 6 R Electric Shock or Withdrawal of foot Buzzer a2 BEHAVIORISM H. Cason has shown that stimulus substitution takes place with wink- ing. The unlearned or unconditioned formula is as follows: seh LN Sab dati Naate Be aOR Sasa MEER GHEY 1 R (1) Bright light Rapid wink (2) Rapid approach of ob- (One of the fastest of jects towards eye human reflexes) (3) Irritation of cornea or conjunctiva of eye (4) Injury to lid itself (cutting, electric shock, etc. ) The noise of a telegraph sounder, or the slight click of a relay will not cause the wink reflex, but if the eyelid is electrically shocked just as the telegraph sounder or relay is sounded the substitution takes place rapidly. It is interesting to note that the substituted stimulus calls out a more rapid wink than the unconditioned stimulus. Again I cannot in a single lecture tell you much about how service- able this method is in teaching us to understand the makeup of a human being. Here too, we can as in the glandular field so “fix” a given stimulus. say a tone, noise, sight, or smell, that only that particular stimulus will call out the response. A thousand noises go on around the dozing mother as we showed on p. 19, without calling out the response of running to the child, but let the child itself stir or even murmur and up she springs. An auditory stimulus can be so strongly fixed, for example, middle C (256 d.v.) that another tone a fraction higher or lower will not call out the response, In Unstriped Muscular Reaction Considerable work has been done upon the conditioning of unstriped muscular tissue. The circular unstriped muscles of the stomach begin their rhythmical contractions after the stomach has been emptied of food. These so-called hunger contractions serve as the most powerful general stimuli we know. They initiate general bodily reactions usually called exploratory. After food has been obtained and eaten the contractions die 1 In daily life I have seen many times an accidental contact with a hot electric iron or radiator condition a child (substitution of visual for tissue destroying, tactual stimulus) after one joint stimulation, We are shot through with such accidental conditionings from earliest infancy onward. HOW TO STUDY HUMAN BEHAVIOR $3 down. It is perfectly possible to change the rhythm of these reactions and make them dependent upon our regular meal time. The well-brought- up baby fed every three hours wakes up promptly at the end of the three hour interval and begins to fuss or cry. Change the interval to a four hour one and after a few days the infant wakes up promptly at the end of the fourth hour. One of the most interesting pieces of experimental work done in this field is that of Cason on the pupillary reflexes. There are two sets of unstriped muscular fibers in the eye. When the radial set contracts the pupil dilates. When the circular or sphincter set contracts the pupil grows smaller. The unconditioned formula is: LUE WR tect tse R aca DE LIOR pare ARC ME MAL IA (U) R Increase in light intensity Closure of pupil Decrease in light intensity Dilatation of pupil Stimulus substitution takes place here as in the various other reflexes. By stimulating the subject with an electric bell or a buzzer just as we increase or decrease the intensity of light falling on the retina, we finally condi- tion the subject so that the sound stimulus alone will call out either dilata- tion or constriction of the pupil, Substitution In the Field of Total Bodily Reactions (Conditioned Emotional Reactions) In Lecture 7 where we talk of so-called emotional reactions I will take up some experiments which show that certain unconditioned stimuli arousing total bodily reactions called “fear”, “rage”, “love”, etc., can be substituted for just as in the simple reflex field we have just studied. This accounts for the ever-increasing number of stimuli that can call out emotional (really visceral) reactions. This experimental work does away with the necessity for any “theory” of the emotions such as that of James. Though I suppose the introspectionists will be writing a hundred years from now as though James really had a theory of the emotions. Let us leave this discussion to a more appropriate place. Summary of Experiments on Stimulus Substitution In a single lecture it is impossible to do more than just sketch in a few general words the way the human body becomes conditioned. The main point to emphasize here is that practically every responding organ 34 BEHAVIORISM of the body can be conditioned; and that this conditioning takes place not only throughout adult life but can and does take place daily from the moment of birth (in all probability before birth). Most of this organiza- tion takes place below the verbalized level. Indeed the glands and un- striped muscular tissue do not belong to our so-called voluntary systems of responses at all. All of us are shot through with stimulus substitutions of one kind or another which we know nothing about until the behaviorist tries us out and then tells about them. This field lies wholly outside the introspectionist’s field. He can get no grip on such reactions. This is an added proof that introspection can at best yield only a very meagre and incomplete kind of psychology. Later I shall attempt to show that “introspection” is nothing but another name for talking about bodily reactions which are taking place. It is not a gen- uine psychological method at all. The importance of early conditionings in building up bodily attitudes, especially on the emotional side, is almost undreamed of. It is practically impossible for us in adult life to have a “new” stimulus thrust upon us that does not arouse this vestigial organization. This work helps us, too, in understanding why behaviorists are growing away from the concept of instinct and substituting for it bodily sets and attitudes. Other Experimental Methods In one brief hour we can hardly hope to even mention by name the various methods—even the worth while objective ones used in behavioristic studies. We mention a few here to give you a little insight into their numbers. Many of the methods center around learning and retention— methods for studying the effects of drugs, hunger, thirst, loss of sleep, etc.—methods for studying conditions that affect the performance of acts after learning has been completed; methods for studying emotional re- actions, such as the various forms of free and controlled word reactions— galvanometric studies of emotional reaction. Methods for studying the relative strength of hunger and sex stimuli (Moss’ recent work). Methods of eliminating sense organs and parts of the brain in animals in order to determine sense organ roles and the rdle of various parts of the nervous system. (In work on humans in this field we have to wait for accident to prepare our subjects.) : The So-Called “Mental” Test as a Behavioristic Method During the past quarter of a century, in this country especially, there has grown up an enormous number of so-called mental tests. For a time HOW TO STUDY HUMAN BEHAVIOR od it looked as though psychology would go test mad. Tests grew up with a mushroom-like growth only to flourish for a few days and then be revised by the next experimenter. Recent years have seen a gradual elimination a many of the tests and the gradual development and standardizing of a ew. Today these general types of tests are in common use: First Grade Intelligence Tests, Kindergarten Tests, Individual Will-Development Tests, “Intelligence” Tests: French, Latin, Sight-Singing, Arithmetic and Classification Tests, Self-Administering Tests of “Mental” Ability, Mechanical Aptitude Tests, Group Tests of “Mental” Ability. Employment Tests, Vocational Guidance Tests, Spelling and Reading Tests; Typewriting and Stenographic Tests. In building these tests hundreds of thousands of children and adults were used. One can but admire the patience and assiduity of the origi- nators of these tests. Once the test has been worked out it becomes a tool. The main purpose behind all testing is to find a measuring rod for classifying masses of individuals according to level of performance, ac- cording to age, and the like; to show up deficiencies and special abilities, racial and sex differences. Two rather wild ideas have grown up about tests: (1) The claim has been made that there is such a thing as “general” intelligence per se; and (2) that there are tests that enable one to differentiate “native” ability from acquired ability. To the behaviorist tests mean merely devices for grading and sampling human performance. Social Experimentation It can be seen at a glance that in all social experimentation we have two general procedures. (1) We attempt to answer the question “What would happen if we should make such and such changes in social situations ? We can’t be sure that we will be any better off, but anything is better than 36 BEHAVIORISM what we have now. Let us make a change.” Usually social situations when they become intolerable cause us to dash blindly into action without arousing any verbal correlates such as I have indicated here. We can phrase the other procedure (2) as follows: “We want this individual or this group of individuals to do a certain thing, but we do not know just how to arrange a situation to get him to do it.” Here the procedure is somewhat different. Society experiments blindly by trial and error, but the reaction is known and approved. ‘The stimulus is manipulated not for the purpose of seeing what in general will happen but to bring about the specific action. You may not clearly see the differ- ence between the two types of procedure, but a few examples should clear it up. First we all must admit that social experimentation is going on at a very rapid rate at present—at an alarmingly rapid rate for comfortable, conventional souls. As an example of social experimentation under No. 1 above, we have war. No one can predict what changes in reaction will be brought upon a nation when that nation goes to war. It is a blind manipu- lation of stimuli on a par with the experimentation of the child when he knocks down his house of blocks so patiently and laboriously constructed. Prohibition was only a blind rearrangement of a situation. The saloon brought a series of actions condemned by society. The conventional individuals in the community, without being able to make any reasonable prediction as to what would occur, tore down the whole of the old situa- tion and created a new one by ratifying the 18th Amendment. It is true that here they expected certain results—the doing away of drinking, the depletion of prisons of their inmates, a lessening of extra-marital inter- course, and the like. But any student of human nature or even of geog- raphy could have predicted that those results could not come although he might have been unable to predict what would occur. The result, except in the smaller towns, of course, has been quite contrary to these expectations. Certainly in and near the larger cities (where legal control is less effective and where public opinion is less of a factor in control) our prisons are more crowded today than ever. Crime is especially rampant, particularly homicidal crimes. The latter are beginning to arouse the concern of life insurance companies. One company in 1924 lost more than three quarters of a million dollars due to homicides alone. Then, too, thousands of citizens have been shot while engaged in rum running or have died from alcohol poisoning. In spite of it all, the prohibition law has been trampled under foot. With the successful breaking of this one law, fear of law has been removed; and when a taboo has been broken with impunity not only HOW TO STUDY HUMAN BEHAVIOR Of does that particular taboo of the medicine man lose its grip, but all of the taboos of that particular medicine man tend to become ineffective. What occurred in primitive society occurs today. All laws are unquestionably more lightly esteemed, The destruction of the monarchy in Russia and the formation of a Soviet government is another example of blind manipulation of situa- tions. Neither friend nor foe could predict what changes in behavior would accrue. The fact is that this change has annihilated industrial prog- ress in Russia and has thrown back the intellectual and scientific progress of the Russian people possibly hundreds of years. Without further elabo- ration we can formulate several of these problems under our general scheme; Stimuli given Reaction—outcome—too complicated for prediction SIRE MON SE RIUUR MLCUNE SILI TUR na Un OY Bnet R Overthrow of monarchy; formation — fy of Soviet government War 5 Prohibition c Easy divorce ° No marriage ° Children brought up in ignorance of their parents ts Substitution of physiological ethics for religion 2 Equalization of wealth ° Elimination of ? hereditary wealth, etc. In this type of social experimentation society often plunges—does not feet its way out by means of small scale experimentations. It works with no definite experimental program in front of it. Its behavior often becomes mob-like which is another way of saying that the individuals composing the groups fall back upon infantile behavior. Similarly, social experimentation goes on in (Z) above. Here the reaction is already known and approved by society—marriage, continence in the unmarried, joining the church, the positive actions demanded in the 38 BEHAVIORISM ten commandments and the like are examples of such approved reactions. Again we can summarize these in our formula: Geni SRA RhcbinaNet ye aL NAM ait ila R ? Marriage under modern financial pressure 4 Continence in great cities where social control is difficult Ng Joining the church . Truthfulness f Rapid acquisition of skill in a special line és Correct deportment etc. Our experimentation consists of setting up one set of stimuli after another until the given specified reaction follows from the correct grouping of stimuli. In trying to arrange these situations, society often works as blindly and as haphazardly as does the infra-human animal. Indeed if one were to characterize social experimentation in general during the past 2000 years one would have to call it precipitous, infantile, unplanned, and say that when planned it is always in the interest of some nation, political group, sect or individual, rather than under the guidance of social scien- tists—-assuming their existence. Never, except possibly at certain periods of Grecian history, have we had even an educated ruling class. Our own country today is one of the worst offenders in history ruled as it is by professional politicians, labor propagandists and religious persecutors. May I call your attention here to the fact that behavioristic psy- chology, taking as it does its problems genetically and going from the simple to the more complex, is amassing a wealth of information on the reactions following stimuli and on the stimuli underlying given reactions, that will prove of inestimable benefit to society? Believing that his science is basal to the organization and control of society, the behaviorist has hoped that sociology may accept its principles and re-envisage its own problems in a more concrete way, What Can We Learn by Commonsense Observation? So far we have talked mainly about technical methods. Cannot we achieve a commonsense psychology personally helpful by merely watching people? The answer is yes, if we will observe them systematically and over a long enough period of time. Indeed every human being already has HOW TO STUDY HUMAN BEHAVIOR 39 considerable organization in psychology whether he has studied it or not. Where would we be in our social life if we could not more or less confi- dently predict responses and puzzle out the possible effect of stimuli? The more observations you make upon other people, the better psychologist you become—the better you can get along with other people—and almost half the battle for a more sanely adjusted life comes from this ability to get along with people. One does not even have to become a student of condi- tioned responses, helpful as this study is, in order to learn practical psy- chology. I visited a man over the weekend to whom I promised to try to give a little helpful practical psychology. He had not been getting along too well in his work. Monday morning he arose, sore and sleepy from the strenuous exercises engaged in over the weekend. He groaned aloud and complained about the unsatisfactory character of all vacations and was just about ready to take a mournful shave and a hot bath. I said to him, “Sling your arms and legs about a bit and do your daily dozen and take a tepid bath. This will set you up.” This verbal stimulus led to the act. He went down to breakfast feeling fit. But his eggs were overdone. He was just ready to “call” the maid but I noticed a certain stiffening of her body and a certain snappiness to her words much as though she said, “I don’t like weekend guests anyway and it serves you both right.” I whis- pered to my host, “Have a care; the Irish biddy is just fretting to go ona rampage. You had better call your wife up by phone when she wakes up and let her scold the cook.” We rushed for the train only to miss it by twenty seconds. He stamped his feet and cursed and said aloud, “This is the first time in three months that train has been on time.” His reactions were almost infantile in character. He calmed down finally and we took a later train to the office. His whole tone was lowered as anyone could observe by watching him. His day had started wrong. Previous commonsense observation had given me, as a behaviorist, a store of data to predict that with his temperament his day might go very wrong indeed, considering the start he had. This situation called out from me the overt verbal response: “You'll have to watch your step all day with the people you come in contact with or you'll hurt somebody’s feelings and make a worse ending to a day that started badly,” This gave him a new start. He smiled when his secretary handed him the mail. He plunged into his work. It gripped him and soon he was lost to the world in the technical duties for which he is peculiarly fitted. When lunch time came he slackened up in his work and I happened to hear his 40 BEHAVIORISM voice raised in protest while talking with one of his associates. Observa- tion of his family life over the weekend had taught me a lot. I was able to predict what the probable situation was that was upsetting him. I thought I could again change his world for him, and I said, “It’s too bad you didn’t ask your wife to come in to town and have lunch with us today. I heard her break her date yesterday for lunch with Mr. and Mrs. Jones, (his wife, much to his distress, being particularly friendly with Mr. Jones) while you were out tuning up the car.’ Being an unpsychological person, his relief was obvious and his next hour was his best. If I had the time, I could take you over his whole business day and back to his home life in the evening. Without asking him to introspect or psychologize or psycho-analyze himself, I could detect his weak spots, his strong points, where he went wrong with his children, where he went wrong with his wife. Would you think it strange if I said that the behaviorist by training him both in principles and in particulars, could almost remake this very intelligent individual in a few weeks’ time? Would you think it boastful if I stated that the behaviorist claims that his psychology is one which has hopes of entering deeply into the life of every individual at every point? But you say, “I am not a psychologist—I cannot go following people around telling them to go easy here and hard there.”’ This is true but are you sure of yourself? Has behaviorism nothing to teach you about your own life? I think you will admit that you have a lot to learn but you would not try to lay bricks on your own house until you had learned how to lay bricks. ‘So with personal psychology you have to watch other people day by day—you have to systematise and classify your data—throw them into logical moulds—and verbalize your results, e. g. “George Mar- shall is the quietest man I know. He is always even-tempered and he always speaks in a low even tone. I wonder if I could learn how to talk like a gentleman.” This verbal’ formulation serves you as a stimulus (implicit kinaesthetic word stimulus). It may lead to a changed response; for words whether spoken by others or spoken subvocally in your own throat are just as strong stimuli, lead just as swiftly to action, as hurtling stones, threatening clubs and sharp knives. If I were an experimental ethicist I’d point out to you the importance of maxims—how potently cut and dried verbal formulae serve as stimuli for shaping our own reactions. This is especially true when those formulae are handed down by persons in authority—by parents, teachers, advisers. Again, if we were studying ethics, I’d point out to you the reasonableness HOW TO STUDY HUMAN BEHAVIOR 41 of arriving at such formulations from your own abundant observation, rather than blindly accepting them second hand. But, I think, I would just as quickly tell you not to reject the results of these collective social experiments—now crystallized into verbal formulae and handed down from father to son and from mother to daughter, until your own tentative and small scale social experimentation has given you more trustworthy formulations. In other words, I am trying in this early lecture to convince you that the behaviorist is not a reactionist—not against anything or for anything until it has been tried out and established like other scientific formulations. To know what is ‘good’ or ‘bad’ for the human organism—to know how to guide man’s conduct on experimentally sound lines is beyond us at present. We know far too little of the makeup of the human body and its needs to be dogmatic in our prescription or in our proscriptions, iil THE HUMAN BODY What It Is Made Of, How It Is Put Together, and How It Works Part I. The Structures That Make Behavior Possible. NTRODUCTION :—In this lecture and in the next we have what many think is a difficult task—to learn something about the way the human body is put together and the way it works. Does it seem ridiculous to try to do this in the course of a lecture or two? Let us give it a fair trial. You may be surprised to find how accurate a picture of the body you can get in even one single hour. The behaviorist is interested in the way the whole body works: If you will pick up a physiology or an anatomy you will find that the human body is studied part by part—the digestive apparatus, the circulatory apparatus, the respiratory apparatus, the nervous system, and soon. The physiologist has to carry out his experimental work first upon one organ and then upon another. The student of human behavior, by contrast, works with the whole body in action. It would be possible for him to carry out his studies without any knowledge of the separate parts whatsoever, but we do not need to work thus blindly. The study of the body is helpful to the be- haviorist. Let us borrow as many helpful things as we can from phy- siology. While the whole body can do many things, there are very definite limitations to its possibilities of functioning and these limitations are due to the material out of which the body is composed and to the way that material is put together. I mean by this merely that there is a limit to the speed with which we can run; to the loads which we can lift; to the length of time we can go without food and without sleep and without water; that the body needs special types of food—that it can endure only a certain amount of heat for a certain length of time, or a certain amount of cold for a definite period ; that it must be supplied with oxygen and other special materials. Even an hour’s study will convince you that the human body, while beautifully put together to do many things, is not a treasure house of mystery but a very commonsense kind of organic machine (and by organic machine we mean something many millions of times more complicated than anything man has yet succeeded in making). 42 THE HUMAN BODY 43 Should We as Behaviorists Be Especially Interested in the Central Nervous System? Because he places emphasis on the facts of adjustment of the whole organism rather than upon the working of parts of the body, the behaviorist is often accused of not making a place in his scheme for the nervous system. To understand why it hurts the feelings of the intro- spectionist for the behaviorist to place no more emphasis on the brain and the spinal cord than upon the striped muscles of the body, the plain muscles of the stomach, the glands, etc., you must remember that the nervous system to the introspectionist has always been a mystery box—whatever he couldn’t explain in “mental” terms he pushed over into the brain. Many of our so-called physiological psychologies are filled with pretty pictures of brain and spinal cord schemes. As a matter of fact we do not yet know enough about the functioning of brain and spinal cord to draw diagrams ~ about their functions. For the behaviorist the nervous system is, Ist, a part ‘of the body—no more mysterious than muscles and glands; 2nd, it is a specialized body mechanism that enables its possessor to react more quickly and in a more integrated way with muscles or glands when acted upon by a given stimulus than would be the case if no nervous system were present. There are many animals and free swimming plants without nervous systems. Their range of adjustment is limited and their reactions to touch, light, sound, etc., are slow. You can react almost instantly with your hand when any part of your body is touched. The nervous system speeds up the passage of the message (known scientifically as a propagated disturbance) from the sense organ (where the stimulus is applied) to the reacting organ (the muscles and glands). Where there is no nervous system the message still travels but it travels slowly, This discussion should show you that the behaviorist has to be vitally interested in the nervous system but only as an integral part of the whole body. Different Types of Cells and Tissues That Make up the Body What is the Body Made Of? Nearly everyone knows today that the body is composed only of cells and the products that the cells manu- facture. But what is acell? The cell is a minute portion of living sub- stance—most cells are so small that they can be seen only under a high eens a 44 BEHAVIORISM power microscope. It is enclosed usually by a membrane. The cell as a whole always contains a mass of protoplasm (a very complex chemical substance) in which granules of various kinds may be seen (possibly stored products which may be used for food for the cell or for secretion). Each cell contains a small oval nucleus (or more than one). The nucleus contains a network of so-called chromatin material (material which takes on a characteristic stain when certain dyes are used on it). The nucleus in some way presides over the whole activity of the cell. Many cells main- tain their characteristic appearance throughout the life of the organisms. Others are obscured soon by their outgrowths or processes or by the very materials which they themselves secrete. If your skill in chemistry and physics and physiology had gone far enough and you were called upon to build a human body what different kinds of cells would you use and into what kinds of patterns (elementary tissues) would you weave these cells? It has been found that four different kinds of cells and their products form the four fundamental tissues of the body. These four fundamental tissues enter into various combinations to form every organ of the body, such as skin, heart, lungs, brain, muscles, stomach, glands, etc. (1) Cells for Covering the Body and Lining All Openings: In the first place you would want cells which you could weave into a membrane to cover the whole of the body—to form the outside layers of the skin. In places you would want to modify the cells in this tissue to form the nails of the fingers and toes and the hair and the teeth. In other places such as the glassy window of the eye ball (the cornea) you would want to modify the cells of this tissue so that they would admit light. Then you would want to line all of the inside tubes and cavities, such as the whole of the alimentary tract—mouth, back of throat, stomach, small intestines, large intestines ; you would want to line the blood vessels and the openings in the brain (ventricles and spinal canal). You would want to form or weave these tissues into the structures we call glands and to modify the cells again so that they would secrete fluids—such as tears, sweat, wax, saliva, and dozens of other fluids and chemicals which the body needs for its own use or which the body must excrete or get rid of. Let us call the cells we use for these purposes (1) epithelial cells, and the tissues they form epithelial tissue. We shall see further on that we shall need very highly specialized forms of these epithelial cells to furnish the sensitive THE HUMAN BODY 45 element in each of our sense organs. Fig. 1 shows some individual epi- thelial cells and Fig, 2 a gland made up of them. rs a Ks. Ss & ) i fi Seances, “a y <™ C + . Ls oa, yi. Vas VF o> ~ “aX aA te (er “in i 24 fe po Epithelial cells put together to form asmall sland ‘Two types of epithelial cells Fig. a (2) Cells That Form Tissue for Supporting and Connecting Bodily Parts: You could not go very far in constructing man with one type of cell and the tissue it forms. You would quickly need strong tissue for tying the bodily parts together. You would want heavy elastic tendons to attach muscles to. You would want strong cartilages to give form to your nose and to hold your windpipe open. During the embryonic (intra- uterine) life of your infant you would need sturdy framework upon which mineral salts could be deposited for forming bones (after the bones are formed by these deposits the connective-tissue framework disappears). You would want to sheathe your bones with a tough fibrous coating (peri- osteum) and to put buffers where bones come together and you would want very strong tough fibres (white fibro-cartilage) to tie the moveable bones together. All of this supporting connective framework is made up of connective-tissue cells. The tissues themselves are called connective tissues (cartilage and bone, elastic, fibrous, areolar). Fig. 3 shows two connective-tissue cells that enter into the structure of the bones, (3) Cells That Form Our Muscular Tissues: We would want to build our human so that it would go from place to place; so that its heart could beat and it could breathe; so that its stomach could get smaller or larger, its blood vessels could expand or contract—in other words, we 46 BEHAVIORISM need to provide locomotion for the body as a whole and for changes in the shape and size of many of the hollow internal organs (e. g. the stomach must vary considerably in size; the blood vessels have to vary in size). To perform all of the varied muscular functions of the body we need really two kinds of muscular cells and two kinds of tissue. i Cannective tissue cells (steoblasts) F pe 3 (a) Striped or Skeletal Muscle Cells and Striped Muscle Tissue: The striped muscle cells are on the average about 1/500 of an inch in diameter. They are often an inch or more in length. The cells are uni- form throughout their length and there is no branching’. The cell is made up of alternate dark and light stripes which run across the length of the cell. This gives the cell its name—cross striated or striped. Like all other cells, muscle cells are supplied with a nucleus—usually with several nuclei. Over each cell is a tough connective-tissue membrane (called sar- colemma). It usually takes hundreds and thousands of these cells to form a single muscle (striped muscle tissue). Over the muscles as a whole there is also a well marked connective-tissue sheath (called the epimysium). Intermixed with muscle one finds the blood vessels which feed them. t In the heart we have striped muscle of a slightly different type. Here the individual cells are short and show short intercommunicating branches. Since this type of muscle is found only in the heart and is responsible for the rhythmic beat of the heart, we shall have very little further to say about it. Hereafter throughout these lectures where we speak of striped muscles we shall mean (a) above. THE HUMAN BODY 47 This is Fig 4 the way the § ; vA y__nerve fibre or axone = great muscles PAE REE Cra , such as_ the biceps of the arm, the mus- cles of the leg RULED? AE eeeE ETT and. tieten ke eA FRO it tongue, the SA So Ee six big mus- cles that con- Bis Parts of two stnpec muscles trol the eye cells shown with motor nerve are made up. endings Our striped muscles are used when- ever movement has to be rapid or where big masses have to be moved. Fig. 4 shows part of two individual striped muscle cells and the way the motor nerve fibres enter them. (b) The Unstriped or Smooth Muscle Cells and Smooth Muscle Tissue: The cells which go to make up the wunstriped smooth muscle tissue are thin, Smooth muscle cell with a herve tibre entering it . The dark elongated, almost hairlike portion in the center is the nucleus SULUCULES ums SEOn Hig he. Oc These cells are grouped into F S layers to form muscular g ; coats. Unstriped muscular tissue forms the chief mus- cular coat of the stomach, intestines, the bladder, sex organs, the iris of the eye (for opening and closing of the pupil), the walls of ducts (tubes ) leading from glands, and the arteries and veins. The Nerve Cells and Nervous Tissue: We still need one other type of cell and the tissue formed from it to perfect our human being. The human animal (as well as all other higher vertebrates) must be able to respond quickly and complexly to stimuli. We know that stimuli are effective only when applied to an appropriate sense organ. We know that the animal must respond with either striped or unstriped muscles, with glands, or with combinations of these. Oftentimes the point where 48 BEHAVIORISM dendrites (<=>—collateral or i side branch A axone ending in awe 7 & striped muscle Fig.6 One type of neurone—the lower motor neurone (After Barker) THE HUMAN BODY 49 the Sensory stimulus is applied is very far distant from the point where the reaction takes place. For example, we may run a thorn into our foot. Immediately we stop, bend over with our trunk, grasp the thorn with our fingers and pull it out. This reaction could not take place unless we had specially differentiated and highly developed nerve cells with their pro- cesses—put together in such a way as to form an actual neural pathway extending from the skin of the foot into the spinal cord, then up the spinal cord to the brain, from the brain back to the spinal cord and from the spinal cord out to the muscles of the trunk, hand and fingers. Nerve cells and their processes are the only bodily structures capable of connect- ing sense organ with muscle in this speedy, intimate way. So far as general structure goes, nerve cells are not very different from other cells in the body. Each nerve cell consists of a cell body with its outgrowths or processes—sometimes the processes are few in number ; sometimes there are hundreds of them. If we take as our example a cell from the spinal cord (Fig. 6) (so-called lower motor neurone), we find a large cell body with a nucleus. Growing out from the cell we find many short branches closely matted around the cell body. These are called dendrites because they look like the branches of a tree. At one point a slender fibre leaves the cell and extends for a longer or shorter distance (it may vary in length from the merest fraction of an inch to several feet). This slender process is called an axone or axis-cylinder. Often during its course it throws out side branches called collaterals. A fatty sheath (called the medullary sheath) clothes the whole of the axis-cylinder with its collaterals (for details of axone, see Fig. 7). This fatty nodes(of Ranvier) axis cylinder medullary sheath Fig. 7 A diagram of a part of a nerve fibre The axis cylinder, consisting of a large number of very fine fibrils, makes up the center of the nerve fibre. The dark outside portion represents the medullary sheath. At certain definite intervals the medullary sheath is con- stricted. These constricted portions are called “‘nodes’” (of Ranvier). sheath is not present on the dendrites. The whole structure so far described is the cell with its processes. The cell with all of these processes is usually called a neurone. There are many forms of these cells, some 50 BEHAVIORISM with only a single process such as the afferent neurones of the spinal cord (those that connect the sense organs Another type of neurone the so with the spinal called sensory or atferent neurone