Relation to Neurology. — It might be supposed that psy- chology would lean most heavily upon neurology. Indeed, this has been the general assumption in the past. Gradually we are coming to the point of view that psychology is more dependent upon such subjects as physiology and certain branches of medi- cine such as hygiene, endocrinology, the chemistry of metabolism, pediatrics and psychiatry, than upon neural anatomy. In the past we have been too content with making brain pictures and mechanical neural schema to always look carefully enough at our behavior facts. We need in psychology all of the available facts that the neurologists can give us, but we can very well leave out of consideration those ingenious puzzle pictures that compare the action of the central nervous system with a series of pipes and valves, sponges, electric switchboards, and the like. Some notion of the elementary guiding principles in neurology is certainly essential to the beginner in psychology, such as the way sense organs are connected with the central nervous system, and the central nervous system with the muscular and glandular sys- tems. In Chapter IV we touch upon some of the more elementary features connected with the arrangement and functioning of reflex pathways.
Relation of Psychology to Physiology. — It has been claimed by some that behavior psychology is really physiology. That this is not the case appears from even a casual examination of the respective scopes of the two provinces. Physiology teaches us concerning the functions of the special organs. For pur- poses of experimentation and exposition, the heart, liver, lungs, circulation, respiration, and other organs are isolated, and they are discussed as though they functioned in an isolated way. Muscle-nerve preparations are taken out and their properties investigated; glands and their action are likewise experimented upon. All of the functions of the bodily organs are gone over from this standpoint. It is not meant to assume that physiolo- gists deal wholly with organs in isolation. Certain combined 20 PSYCHOLOGY processes are studied, such as metabolism, Digestion, effects of poisons, etc., but nowhere in physiology do we get the organism, as it were, put back together again and tested in relation to its environment as a whole.
From our discussion of the scope of psychology we are now prepared to see that when the physiologist has learned all that he can about the functioning of the separate organs of the body of man, he has encroached upon our field only in a very slight degree. Our task begins only when the physiologist puts the separate organs together again, and turns the whole (man) over to us. The physiologist qua physiologist knows nothing of the total situations in the daily life of an individual that shape his action and conduct. He may teach us all there is to know about the mechanism of stepping, but it is not his task to determine whether man walks before he crawls, the age at which walking begins, whether walking begins earlier in boys than in girls, or whether defective children walk at a later age than normal children. Again, he may teach us a great deal about the func- tions of the kidneys, the bladder, and of the sphincter control of the latter; but of the special situations (outside of disease entities) which may lead to incontinence in children, his science teaches him nothing, nor of methods of controlling this mal- adjustment. In studying psychological functions — for example, the emotions — it does not help us very much to try to picture what chemical and neural processes go on in the brain. We get a very incomplete but a somewhat better view if we consider what glandular action goes on during emotional states. But even glandular action is not easily observed by methods' which are known to-day. We can, however, study the reaction states we popularly call sadness, elation, moroseness, rage, fear and love, from the standpoint of what the organism can do in these states, and whether the smooth running of the general system of organized habits is facilitated or disturbed by the presence of emotional activity. We can, further, often determine by a study of the life history of the individual how frequently such dis- turbances come about, and can trace out the causes or factors leading to their onset. Physiology has nothing to tell us of the character and personality of different individuals nor of their PROBLEMS AND SCOPE OF PSYCHOLOGY 21 emotional stability or lack of emotional control, nor as to what extent their present place in life is dependent upon their up- bringing. Physiology tells us nothing of man's capacity to form and retain habits, nor of the complexity of man's habit organization. Hence, if we wish to predict whether an individual is capable of meeting or rising above the environment to which he is at present but poorly adjusted, we should have to go to psychology and not to physiology for our answer. In thus! emphasizing the entire theoretical independence of the two fields, let us not set up a false impression of antagonism. Physiology is psychology's closest friend among the biological sciences. We can hardty move a step in psychology without using physiological 'data. But in this we are not different from the other biological sciences, or indeed from medicine itself.
Overlapping of the Two Fields. — Occasionally we find physi- ologists who have dealt with functions which overlap the field of human behavior. As examples, we cite the work of Cannon on the bodily effect of violent emotional disturbances, and of Carlson and others on the question of the reactions which are present in the stomach in the absence of food. Where the two fields overlap most, however, is probably in the study of the con- ditioned motor secretion reflexes and in the realm of sensory physiology. This latter topic seems no longer to seriously interest the physiologists, and where they have shown interest in it — in this country at least — it has been mainly pedagogical. Most of the work in sensory physiology has been done by psy- chologists. Until the recent work of Pavlow and Bechterew and their students, physiologists have shown little interest in the study of habit formation, which general topic is one of our cen- tral ones. In general it may be said that there is^ some over- lapping in the two fields, but that it does not keep them from being separate disciplines. In cases where there is an overlap- ping, the methods and points of view of the two sciences in no I wise differ.
Relation of Psychology to Medicine. — Up to the present time psychology has been of only slight service to psychiatry and medicine generally. It should form a background for the whole field of medicine. But it has dealt hitherto so largely with specu- 22 PSYCHOLOGY lations and with philosophical considerations that its usefulness for this purpose has been seriously restricted.
The physician, whether medical specialist or general prac- titioner, would like to know something about the method of approaching and handling his patients. He must encounter — and he must be prepared to encounter — such things as stubborn- ness and unyieldingness in his human subjects, and he must learn to study his patients in relation to their present environ- ment, and to go back into their life history for an understand- ing and explanation of such attitudes. He must learn how to size up his patients, and to get at the details of their individu- ality and characteristics. He must be able to tell whether the patient can do what he is told to do, and whether he has suf- ' ficient assets to meet the environment in which he has to live, and whether he has sufficient assets to rise out of the environment which is unsuited to him. These facts on character adaptation cannot be expressed in any other terms than behavior terms. There are, to be sure, factors which concern every one who has to deal with his fellow-man, but on account of the intimate rela- tionship existing between the patient and his physician they are of especial importance to the latter. The psychiatrist has not neglected these factors; indeed, it has been due to him that they have been emphasized at all, and it is largely through his efforts that we have a well-developed and systematic technic for isolating the factors of importance in the life history of the patient. So far as psychiatry is concerned, I think we can say that the psy- chology the psychiatrist uses is not different from the psychology we are trying to study. The psychiatrist has to be both a physi- cian, with a specially developed therapeutic technic, and a psy- dioloprist with special interests in certain divisions of psychology. Psychiatry has no special need for detailed studies on reactions to sensory stimuli. Much of the detailed work on habit forma- tion and on the separate analysis of instincts is not of special use to him. On the other hand, any of the material which the psychologist may offer on the subjects of attachment and detach- ment of the emotions, on the genesis of instincts and habits and their inter-relations, on the effect of age, drugs, etc., on habit PROBLEMS AND SCOPE OF PSYCHOLOGY 23 formation and retention, upon false reactions and failures in reactions, on the effect of lesions of the central nervous systems in trained animals, and the resultant success that comes from retraining them, can be utilized by the psychiatrist at once, both in a specific way and by reason of its value in helping him to size up his patients. Most psychiatrists will admit that when the proper kind of psychology is developed they can utilize di- rectly a large part of both its methods and its materials. This appears clearly when we examine the various tests which have been devised by psychologists for evaluating the general behavior levels of individuals. Such tests in one or another form are in common use in every psychiatric clinic. Topics such as "general behavior, " ' ' stream of talk, " k l attitude, " " orientation, "" reten- tion ' ' of recent and past happenings, ' * general information, ' ' the emotional level at which acts are carried out, are discussed in relation to every patient admitted to a psychiatric clinic.
Preparation for Psychology. — In dealing with the native equipment of man, the student will find a background of study of animal behavior a helpful one. As a further preparation for this part of his work, he will find that he needs some equipment in physiology and experimental zoology. His work in habit formation leads him again into physiology and pharmacology for such factors as the effect of age, drugs, chemicals and glandular extracts upon the human organism. The consideration of habit and instinct conflicts, abortive reactions and failures of adjust- ment generally which we see so much emphasized in tics, sympa- thetic chorea, hysteria, obsessions, etc., leads the psychologist into the psychiatric clinic if he wishes to prepare himself to the full- est extent. Business and law are making ever and ever larger demands upon him. Some familiarity with legal and business problems is almost essential. Finally, in order to handle ade- quately experimental data some training in the use of statistical methods is needed. If a start is made early enough by the student who is preparing for psychology, he can obtain training in the above related branches before he begins his special study of psychology. While to-day is a day of specialists, it should not be a day of narrow specialists.
CHAPTER II CHAPTER II PSYCHOLOGICAL METHODS Introduction. — In the preceding chapter we referred several times to psychological methods and procedure. It remains to give a somewhat more extended discussion of objective methods as employed in human psychology. In the end we will find that this preliminary survey of methods will assist us in understand- ing the results which have been obtained in the field of psy- chology.1 Psychological methods in detail are very numerous. When we come to look them over, however, we find that most of them fall within the following general classification: \) I. Observation, with and without instrumental control. I II. The conditioned reflex methods.
(a) Methods employed in obtaining conditioned secretion reflexes. (6) Methods employed in obtaining conditioned \piotor reflexes.
III. The verbal report method. IV. Methods of testing.
These various methods are not completely independent, but the reasons for such a classification will appear after a careful con- sideration of the text.
1 The Instructor is advised at this point to give at least two demon- stration lectures on the simple forms of apparatus employed in psychology, and upon the method of treating the results. We suggest some demonstra- tion of the expressive methods, showing how respiration, vasomotor changes, can be recorded and timed; upon the way of administering the word- issociation test, both with a simple stop-watch and with better timing devices; of the method of recording and timing eye movements by pho- tography as the eye moves in reading, etc. The student should be put through some test such as the Trabue language test, the army alpha test the range of information test, etc. If time permits, the apparatus and used in the study of "memory" and the conditioned reflex should be given. Some familiarity with sense organ experimentation is also advised 24 PSYCHOLOGICAL METHODS 25 I. OBSERVATION WITH AND WITHOUT INSTRUMENTAL CONTROL.
Unaided Observation. — Observation, as the man on the street uses the term, is, of course, the oldest method known to science. We make our observations in all natural sciences by the aid of our sense organs. In one sense instrumentation may be looked upon merely as a device for increasing the number of observations which can be made simultaneously. In a normal individual, vision is the sense most usually employed. When this sense is denied us, or will not work in a particular problem, we depend for observation upon the auditory and tactual sense organs. Under ordinary conditions, smell and taste are not used as organs of scientific observation. At times, however, their use is indispensable in chemistry, medicine, etc. Our muscular sense enables us principally to make observations concerning the movements and positions of our own bodies, serving at the same time crudely the purpose of enabling us to react differentially to the size, weight, and position of objects other than partst of our own bodies.
Practically all of the results which have been obtained in the psychology of common-sense have come through the use of un- aided observation. By such observation we obtain gross changes in the activities of the individual or the crowd, the general behavior of children and animals, and certain aspects of emo- tional and instinctive activity. We must not confuse the ob- servation made by a scientist ivithout instrumental control with the amateurish and muddled observation made by the untrained individual. Some of the finest work we have in biology has been done by scientists without instrumental control. We cite the behavior work of Fabre, Wheeler, and the Peckhams. Unaided observation, however, even when employed by the trained man, becomes a genuine scientific method only when he puts his results down and begins to note exceptions, to draw tentative conclusions, and then to gather new observations to check up such conclusions. In other words, such data must be subjected to statistical methods before conclusions can be verified. We brought out in the last chapter that even without the use of instruments we may learn something about the stimuli which produce responses in human 26 PSYCHOLOGY 26 PSYCHOLOGY beings, and something about the nature of^the acts themselves. Without instrumentation, however, many of the phenomena of conduct cannot be brought under adequate scientific control. At best the unaided method in our field is only a rough and ready one that enables us to proceed in a provisional way. We may illustrate this by the following example: A person comes into the room; we speak to him in an ordinary conversational tone. He does not respond to our words. We immediately infer that the individual has defective hearing. But from such rough observation, even after watching him for several days, we get little indication of the extent of the defect, and of the types of limitations to which he is subject. Again, in the sphere of learn- ing we may note that a given individual fails to learn quickly, and does not retain his training for any length of time. If we wish to get an accurate picture of his defects, one accurate enough to compare with that obtained from another individual, systematic observation with instrumental control has to be employed.
Observation with the Aid of Instrumentation, and Control of the Subject. — Progress in any science can be measured by the extent to which apparatus and improved methods of observation have been employed. This has been well illustrated in 'the tech- nical world, and especially in physics, chemistry and engineering. Psychology likewise early felt the necessity of devising special instruments for the study of behavior. These methods are clearly illustrated both in the field of sensory physiology and in that of the more complicated reactions. In general we may say that whatever phenomenon is open to unaided observation can be more accurately studied where instrumentation and control of the sub- ject are employed. If we are testing the rapidity with which an individual can repeat the separate members of a list of common words, we must have some kind of measure of the process. Un- aided observation is all but worthless. An ordinary watch gives only a rough indication. A V,-second stop-watch gives an ap- proach towards a scientific instrument; a standard chronoscope, indicating x/100 of a second, gives a scientific record which at present is probably a finer measure than we need in psychology.
PSYCHOLOGICAL METHODS 27 The extent to which instrumentation is being employed is clearly recognized in the various devices for photographing and timing eye movements, in the devices for measuring the speed and accu- racy of hand and finger movements, as in tapping, steadiness and strength of grip. The need of accurate apparatus is clearly recognized in the technic used in determining sensory responses, and in the various psychophysical measurements. Instrumenta- tion is just being introduced into the measuring and timing of secretion responses — for example, in the salivary, sweat and indi- rectly in the endocrine glands ( glandular secretions are discussed on page 181). Certain divisions of psychology have all but resisted the use of instrumentation. There have been few experimental studies upon emotional reactions (page 198), few upon internal muscular reactions, and, until recently, few upon the internal responses connected with hunger, thirst, and the temperature responses to stimulation of the alimentary tract. Few, if any, experiments have succeeded in bringing the sub-vocal mechan- isms under control. Indeed, many of the glandular responses have, from a psychological standpoint, not been touched — for example, the possible conditioned reflexes which we may find in the thyroid, adrenal, and sex glands, and in the secretions of the kidneys. At present there is no way of using instrumentation where the individual or group has to be observed for long periods of time, as, for example, in sleep, reaction of crowds to emotion- producing stimuli, and the influence of children upon each other. The Setting of an Experiment. — In general, in most psycho- logical investigations of the laboratory type, where accuracy and control in observation are demanded, the experimenter makes his observations upon one, or, at best, a few subjects. In addition to the instruments necessary to make observations, we must control certain aspects of the subject's environment — depending upon the nature of the experiment, we place him in a dark room, or in a well-lighted room; we leave him in the room alone, or make him react before other people. Indeed, it is often 'necessary to control his diet, sleep, and living conditions, as is illustrated by the experiments which have been carried out upon hunger, thirst, and salivary secretions, the effect upon general behavior of fast- 28 PSYCHOLOGY ing and drugs. We may look upon such controls as the experi- mental setting for an observation. In short, we may say that in order to make accurate psychological observations, we need in- struments delicate enough to suit the general purpose of the investigation. Furthermore, we need to be able to control and modify at will the temporary or permanent environment of the subject. Naturally there are many psychological investigations which cannot be conducted in this way. Certain important psy- chological undertakings probably can never be brought under laboratory control. Reference here, of course, is made to the social problems which psychology sometimes has to study. A youth, for example, is not making good in his school environment: we take him into the laboratory and study his character and tem- perament as best we can, run him through all the necessary tests, size him up, and then we advise certain changes which the parents and teachers should make in his environment. Time must be given for these recommended changes to have their effect. Dr. Adolf Meyer often speaks of his psychopathic patients as experi- ments of nature. There are many problems of this character in psychology that yield only little at the hands of a laboratory man. Much of the work now being done in the field of vocational psychology and in educational training is of this type. In such broad psychological problems the environment is not under the immediate control of the observer. In such cases we do the best we can, calling in all the observational, experimental, and statis- tical aids we can summon.
II. THE CONDITIONED REFLEX METHODS. Introduction. — In the various conditioned reflex methods we have a special example of the way instruments are employed in the making of psychological observation. By means of these methods many phenomena of reaction can be brought under con- trol which cannot be observed by the verbal report methods to be described later. It is impossible for us to state by unaided observation whether action in the salivary glands is accelerated or the reverse by the sight of certain kinds of food. These reflex methods have been in common use in the Russian laboratories PSYCHOLOGICAL METHODS 29 for a number of years. The data obtained by such methods are not entirely new, but the technic of the methods had not been well established until the work of Pavlow and Bechterew appeared. The methods can be employed both upon the muscles and upon the glands. In general they depend upon the following fact: Every fundamental reflex in the body has an appropriate stimulus for the calling out of that reflex. On page 233 we discuss some of the fundamental reflexes. We may anticipate somewhat and mention a few of them here. If the patellar tendon is touched with a small percussion hammer, the familiar kick of the leg appears. If the sole of the foot, or the great toe, is stimulated by an electric current, the foot will jerk back, or the toe will rise. If the finger is pricked or burned, the finger will draw back. In a similar way, if the mouth is stimulated by food, and espe- cially by an acid, the salivary glands will begin to pour out their secretions more rapidly. Let us call the stimuli that pro- duce native or fundamental reflexes, the normal or adequate stimuli to the reflexes. The question before us is whether we can get any other stimulus to touch off such a fundamental or native reflex — whether we can get a transfer or substitution of stimulus. Without entering too much into the details of the method, we find that it is possible to get a stimulus which does not ordinarily call out one of the fundamental reflexes to call it out, provided the proper conditions are observed. It is a real question whether we should call these methods conditioned reflex methods, or substituted stimulus methods. The term "conditioned reflex" seems to be fairly well incorporated in the literature, and it is probably best for us to use that term. In the following para- graphs we shall illustrate this method by taking some simple laboratory situations.
A. METHODS EMPLOYED IN OBTAINING CONDITIONED SECRETION REFLEXES.
Conditioned Salivary Reflex. — The conditioned salivary re- flex has been made popular through the work of Pavlow and his students upon the dog. Not until very recently was it possible for us to use this method upon man, since an operation was neces- 30 PSYCHOLOGY sary to bring the gland to the surface of the cheek. Recently Lashley, of the Hopkins laboratory, has used the simple instru- ment shown below for making the responses of this gland plainly visible to the eye (Fig. 1). The parotid glands (page 176) of the two cheeks are easiest to work with, although the submaxil- lary gland can be used. Each parotid gland has leading out from it a small duct called Stenson's duct. The instrument shown in Fig. 1 consists of a metal disc. 18 mm. in diameter, in which two concentric chambers A and B are cut. The inner one of these is 10 mm. in diameter and 3 mm. deep; the outer, in the form of a circular groove, is 2 mm. wide and 3 mm. deep. The two chambers open through the back of the disc into two separate tubes, C and D, of 2 mm. bore and 15 cm. in length. The tubes are of silver. The instrument is placed against the inner surface ^ ^ FIG. 1. — Instrument for collecting secretions from parotid gland. Explanation of parts in text.
of the cheek so that the central chamber covers the mouth of Stenson's duct, and the air is exhausted from the outer chamber by a suction pump. The disc then clings tightly to the cheek for as long a time as one cares to work. In a few moments the saliva fills the central chamber and begins to flow out through the tube C to a suitable measuring device. When the jaws are closed the tube lies between the cheek and the upper molars, and passes out through the corner of the mouth. The instrument interferes little with talking or eating, and may be worn for hours. The drops of saliva may be recorded in various ways. They may be mon-ly counted and the average number of drops per minute determined, or the drops may be collected in a calibrated tube. We next determine in any individual subject the normal rate of flow at a given interval after food has been eaten. We are then in a position to tell whether certain forms of stimulation which PSYCHOLOGICAL METHODS 31 we may employ increase or decrease the flow. In this way we may test the effect of chewing hard and soft substances, of hot water, cold water, etc. So far as described, the method is at the service both of the physiologist and of the psychologist. Indeed, we may look upon all such tests as purely physiological tests of the functioning of the glands. We find by employing this instru- ment the various stimulating factors which affect the gland. The psychological question now comes up: Is the action of the gland connected in any way with the individual 's habit systems? We find by repeated trials that the sight of unaccustomed objects does not have any effect upon the flow of the glands. On the other hand, if we bring the hungry subject into a situation where he has obtained food, 'and then show him food which he has been in the habit of eating (food positively reacted to), the glands immediately begin to function above normal. In other ,words, these visual stimuli which ordinarily have no effect upon the functioning of the glands, come by the process of substitu- tion to serve as stimuli for increasing the flow of secretion. This probably can be shown most clearly by actual experiment. After determining the ordinary rate of the flow of the salivary gland, a bar of chocolate almond was handed to the subject. He was allowed to smell it, to bring it to his lips, -and to hold it at arm *s length. The following table shows the result of this experiment: