Psychology and Industrial Efficiency

The interest in all these problems of large concerns, in transportation and factory work and complex industries, ought not to make us overlook the fact that on principle the same problems can be found in the simplest industrial establishment. Even the housewife or the cook destroys economic values if daily she has to spend useless minutes or hours on account of arrangements in the household which are badly adjusted to the psychological conditions. She sacrifices her energy in vain and she wastes her means where she herself is under the illusion of especial economy. Scientific management would perhaps be nowhere so wholesome as in kitchen and pantry, in laundry and cellar, just because here the saving would be multiplied millionfold and the final sum of energy saved and of feeling values gained would be enormous, even if it could not be calculated with the exactitude with which the savings of a factory budget can be proven. The profusion of small attractive devices which automatically perform the economic household labor and disburden the human workers must not hide the fact that the chief activities are still little adjusted to the psychophysical conditions. The situation is similar to that of the masons, whose function has also been performed for thousands of years, and yet which did not find a real adaptation to the psychical factors until a systematic time-measuring study was introduced. A manufacturer who sells an improved pan or mixing-spoon or broom expects success if he brings to the market something the merits of which are evident and make the housewife anticipate a decrease of work or a simplification of work, but the development of scientific management has shown clearly that the most important improvements are just those which are deduced from scientific researches, without at first giving satisfaction to the laborers themselves, until a new habit has been formed.

Perhaps the most frequent technical activity of this simple kind is sewing by hand, which is still entirely left to the traditions of common sense, and yet which is evidently dependent upon the interplay of many psychical factors which demand a subtle adaptation to the psychical conditions. To approach, at least, this field of human labor a careful investigation of the psychophysics of sewing has been started in my laboratory.[33] The sewing work is done, with the left hand supported, and the right hand connected with a system of levers which make a graphic record of every movement on the smoked surface of a revolving drum. For instance, we begin with simple over and over stitches, measuring the time and the character of the right hand movements for 50 stitches under a variety of technical conditions. The first variation refers to the length of the thread. The thread itself, fixed at the needle's eye, varied between 3 feet and 6 inches in length. Other changes refer to the voluntary speed, to the number of stitches, to fatigue, to external stimuli, to attention, to methods of training, and so on, but the chief interest remains centred on the psychical factors. We are still too much at the beginning already to foresee whether it will be possible to draw from these psychophysical experiments helpful conclusions. The four young women engaged in this laboratory research will later extend it to the psychological conditions of work with the various types of sewing-machines.

XV

The study of the technical aspect of labor can nowhere be separated by a sharp demarcation line from the study of the labor itself as a function of the individual organism. Many problems, indeed, extend in both directions. The student of industrial efficiency is, for instance, constantly led to the question of fatigue. He may consider this fatigue as a function of brain and muscle activity and discuss it with reference to the psychophysical effort, but he is equally interested in the question of how far the apparatus or the machine or the accessory conditions of the work might be changed in order to avoid fatigue. The accidents of the electric street railways were regarded as partly related to fatigue. The problem was accordingly how to shorten the working time of the motormen in the interest of the public, but it was soon recognized that the difficulty might also be approached from the mere technical side. Some companies introduced seats which the motormen can use whenever they feel fatigue coming and excellent results have followed this innovation. In our last discussions the technical apparatus stood in the foreground. We may now consider as our real topic the psychophysical activity.

Here, too, the leaders of scientific management have secured some signal successes. Their chief effort in this field was directed toward the greatest possible achievement by eliminating all superfluous movements and by training in those movement combinations which were recognized as the most serviceable ones. We may return to the case of the masons in order to clear up the principle. When Gilbreth began to reform the labor of the mason after scientific principles, he gave his chief interest to the men's motions. Every muscle contraction which was needed to move the brick from the pile in the yard to the final position in the wall was measured with reference to space-and time-relations and the necessary effort. From here he turned to the application of well-known psychophysical principles. A movement is less fatiguing and therefore economically most profitable if it occurs in a direction in which the greatest possible use of gravitation can be made If both hands have to act at the same time, the labor can be carried out most quickly and with the smallest effort if corresponding muscle groups are at work and this means if symmetrical movements are performed. If unequal movements have to be made simultaneously, the effort will become smaller if they are psychically bound together by a common unified impulse. The distance which has to be overcome by hands, arms, or feet must be brought to a minimum for each partial movement. Most important, however, is this rule. If a definite combination of movements has been determined as economically most suitable, this method must be applied without any exception from the beginning of the learning. The point is to train from the start those impulse combinations which can slowly lead to the quickest and best work. The usual method is the opposite. Generally the beginner learns to produce from the beginning work which is as good and correct as possible. In order to produce such qualitatively good results at an early stage, it is left to him to choose any groups of movements which happen to be convenient to him. Then these become habitual, and as soon as he tries to go on to quicker work, these chance habits hinder him in his progress. The movements which may be best suited for fair production by a beginner may be entirely unsuited for really quick work, such as would be expected from an experienced man. The laborer must replace the first habits which he has learned by a new set, instead of starting in the first place with motions which can be continued until the highest point of efficiency has been reached, even if this involves rather a poor showing at the beginning. A final maximum rapidity must be secured from the start by the choice of those motions which have been standardized by careful experiments.

It is also psychophysically important to demand that the movements shall not be suddenly stopped, if that can be avoided. Any interruption of a movement presupposes a special effort of the will which absorbs energy, and after the interruption a new start must be made of which the same is true. On the other hand, if chains of movements become habitual, the psychophysical effort will be reduced to the minimum, inasmuch as each movement finds its natural end and is not artificially interrupted by will, and at the same time each movement itself becomes a stimulus for the next movement by its accompanying sensations. The traditional method, for instance, demands that a brick be lifted with one hand and a trowel with mortar by the other hand. After that the lifting movement is interrupted, the brick comes to rest in the hand of the mason until the mortar has been spread on and the place prepared for the new brick. Then only begins a new action with the brick. This method was fundamentally changed. The laborers learned to swing the brick with one hand from the pack to the wall and at the same time to distribute the mortar over the next brick with the other hand. This whole complex movement is of course more difficult and demands a somewhat longer period of learning, but as soon as it is learned an extreme saving of psychophysical energy and a correspondingly great economic gain is secured. The newly trained masons are not even allowed to gather up with the trowel any mortar which falls to the floor, because it was found that the loss of mortar is economically less important than the waste of psychophysical energy in bending down.

Whoever has once schooled his eye to observe the limitless waste of human motions and psychophysical efforts in social life has really no difficulty in perceiving all this at every step. This ability to recognize possible savings of impulse may be brought to a certain virtuosity. Gilbreth, one of the leaders of the new movement, seems to be such a virtuoso. When he was in London, there was pointed out to him in the Japanese British Exhibition a young girl who worked so quickly that there at least he would find a rhythm of finger movement which could not any further be improved. In an exhibition booth the woman attached advertisement labels to boxes with phenomenal rapidity. Gilbreth watched her for a little while and found that she was able to manage 24 boxes in 40 seconds. Then he told the young girl that she was doing it wrongly, and that she ought to try a new way which he showed her. At the first attempt, she disposed of 24 boxes in 26 seconds and at the second trial in 20 seconds. She did not have to make more effort for it, but simply had fewer movements to make. If such economic gain can be secured with little exertion in the simplest processes, it cannot be surprising that in the case of more complex and more advanced technical work which involves highly skilled labor, a careful psychophysical study of motions must bring far-reaching economic improvements.

Yet the more important steps will have to be guided by special experimental investigations, and here the psychological laboratory must undertake the elaboration of the details. Only the systematic experiment can determine what impulses can be released at the least expense of energy and with the greatest exactitude of the motor effect. Investigations on the psychophysics of movement and the influences which lead toward making the movement too large or too small have played an important rôle in the psychological laboratories for several decades. It was recognized early that the mistakes which are made in reproducing a movement may spring from two different sources. They result partly from an erroneous perception or memory of the movement carried out, and partly from the inability to realize the movement intention. One series of investigations was accordingly devoted to the studies of those sensations and perceptions by which we become aware of the actual movement. Everything which accentuates these sensations must lead to an overestimation of the motion, and the outcome is that the movement is made too small. The concentration of attention, therefore, has the effect of reducing the actual motion, and the same influence must result from any resistance which is not recognized as such and hence is not subtracted in the judgment of the perceiver. Another series of researches was concerned with the inner attitude which causes a certain external movement effect and which may lead to an unintended amount of movement as soon as the weight to be lifted is erroneously judged upon. Closely related studies, finally, deal with a mistake which enters when the movement is reproduced from memory after a certain time. The exactitude of a simple arm movement seems to increase in the first ten seconds, then rapidly to decrease. The emotional attitude, too, is of importance for the reproduction of a movement. I trained myself in making definite extensor and flexor movements of the arm until I was able to reproduce them under normal conditions with great exactitude. In experiments extending over many months, which were carried on through the changing emotional attitudes of daily life, the exact measurement showed that both groups of movements became too large in states of excitement and too small in states of fatigue. But in a state of satisfaction and joy the extensor movement became too large, the flexor movement too small, and vice versa, in unpleasant emotional states the flexor movement was too strong and the extensor movement too weak.[34]

We have a very careful investigation into the relations between rapidity of movement and exactitude.[35] The subjects had to perform a hand movement simultaneously with the beat of a metronome, the beats of which varied between 20 and 200 in the minute. In general the accuracy of the movement decreases as the rapidity increases, but the descent is not uniform. Motions in the rhythm of 40 to the minute were on the whole just as exact as those in the rhythm of 20, and, on the other hand movements in the rhythm of 200 almost as accurate as those of 140 to the minute. Thus we have a lower limit below which decrease of rapidity does not increase the accuracy any further, and an upper limit beyond which a further increase of rapidity brings no additional deterioration. The mistakes of the unskilled left hand increase still more rapidly than the number of movements. If the eyes are closed, the rapid movements are usually too long and the slow ones too short.

An investigation in the Harvard laboratory varied this problem in a direction which brings it still nearer to technical conditions of industry. Our central question was whether the greatest exactitude of rhythmical movement is secured at the same rapidity for different muscle groups.[36] We studied especially rhythmical movements of hand, foot, arm, and head, and studied them, moreover, under various conditions of resistance. The result from 340,000 measured movements was the demonstration that every muscle group has its own optimum of rapidity for the greatest possible accuracy and that the complexity of the movement and the resistance which it finds has most significant influence on the exactitude of the rhythmical achievement. If we abstract at first from the fluctuations around the average value of a particular group of movements and consider only this average itself in its relation to the starting movement which it is meant to imitate, we find characteristic tendencies toward enlargement or reduction dependent upon the rapidity. The right foot, for instance, remained nearest to the original movement at a rapidity of 80 motions in the minute, while the head did the same at about 20. For a hand movement of 14 centimeters, the most favorable rapidity was 120 repetitions in the minute, while for a hand movement of 1 centimeter the average remained nearest to the standard at about 40 repetitions. The mean variation from time average is the smallest for the left foot at 20 to 30 movements, for the right at 160 to 180, for the head at 40, for the larger hand movement at 180, and so on. Investigations of this kind have so far not affected industrial life in the least, but it seems hardly doubtful that a systematic study of the movements necessary for economic work will have to pass through such strictly experimental phases. The essential point, however, will be for the managers of the industrial concerns and the psychological laboratory workers really to come nearer to each other from the start and undertake the work in common, not in the sense that the laboratory is to emigrate to the factory, but in the better sense that definite questions which grow out of the industrial life be submitted to the scientific investigation of the psychologists.

XVI

The systematic organization of movements with most careful regard to the psychophysical conditions appeared to us the most momentous aid toward the heightening of efficiency. But even if the superfluous, unfit, and interfering movement impulses were eliminated and the conditions of work completely adjusted to the demands of psychology, there would still remain a large number of possibilities through which productiveness might be greatly decreased, or at least kept far below the possible maximum of efficiency. For instance, even the best adapted labor might be repeated to the point of exhaustion, at which the workman and the work would be ruined. Fatigue and restoration accordingly demand especial consideration. In a similar way emotions may be conditions of stimulation or interference, and no one ought to underestimate the importance of higher motives, intellectual, æsthetic, and moral motives, in their bearing on the psychophysical impulses of the laborer. If these higher demands are satisfied, the whole system gains a new tonus, and if they are disappointed, the irritation of the mental machinery may do more harm than any break in the physical machine at which the man is working. In short, we must still look in various directions to become aware of all the relations between the psychological factors and the economic output. We may begin with one question which plays a large, perhaps too large, rôle in the economic and especially in the popular economic literature. I refer to the problem of monotony of labor.

In the discourses of our time on the lights and shades of our modern industrial life, all seem to agree that the monotony of industrial labor ought to be entered on the debit side of the ledger of civilization. Since the days when factories began to spring up, the accusation that through the process of division of labor the industrial workingman no longer has any chance to see a whole product, but that he has to devote himself to the minutest part of a part, has remained one of the matter-of-course arguments. The part of a part which he has to cut or polish or shape in endless repetition without alteration cannot awake any real interest. This complete division of labor has to-day certainly gone far beyond anything which Adam Smith described, and therefore it now appears undeniable that the method must create a mental starvation which presses down the whole life of the laborer, deprives it of all joy in work, and makes the factory scheme a necessary but from the standpoint of psychology decidedly regrettable evil. I have become more and more convinced that the scientific psychologist is not obliged to endorse this judgment of popular psychology.

To be sure the problem of division of labor, as it appears in the subdivision of manufacture, is intimately connected with many other related questions. It quickly leads to the much larger question of division of labor in our general social structure, which is necessary for our social life with its vocational and professional demands, and which undoubtedly narrows to a certain degree every individual in the completeness of his human desires. No man in modern society can devote himself to everything for which his mind may long. But as a matter of course these large general problems of civilization lie outside of the realm of our present inquiry. In another direction the problem of monotony comes very near to the question of fatigue. But we must see clearly that these two questions are not identical and that we may discuss monotony here without arguing the problem of fatigue. The frequent repetition of the same movement or of the same mental activity certainly may condition an objective fatigue, which may interfere with the economic output, but this is not the real meaning of the problem of monotony. About fatigue we shall speak later. Here we are concerned exclusively with that particular psychological attitude which we know as subjective dislike of uniformity and lack of change in the work. Within these limits the question of monotony is, indeed, frequently misunderstood in its economic significance.

In the situation of the industrial workman, the attention may be directed toward some small differences which can only be recognized after long familiarity with the particular field. Certainly this field is small, as every workman must specialize, but whether he manufactures a whole machine, or only a little wheel, makes no essential difference in the attitude. The attraction of newness is quickly lost also in the case of the most complicated machine. On the other hand, the fact that such a machine has an independent function does not give an independent attraction to the work. Or we might rather say, as far as the work on a whole machine is of independent value, the work of perfecting the little wheel is an independent task also and offers equal value by its own possibilities. Whoever has recognized the finest variations among the single little wheels and has become aware of how they are produced sometimes better, sometimes worse, sometimes more quickly, sometimes more slowly, becomes as much interested in the perfecting of the minute part as another man in the manufacture of the complex machine. It is true that the laborer does not feel interest in the little wheel itself, but in the production of the wheel. Every new movement necessary for it has a perfectly new chance and stands in new relations, which have nothing to do with the repetition. As a matter of course this interest in the always new best possible method of production is still strongly increased where piece-wages are introduced. The laborer knows that the amount of his earning depends upon the rapidity with which he finishes faultless products. Under this stimulus he is in a continuous race with himself, and thus has every reason to prefer the externally uniform and therefore perfectly familiar work to another kind which may bring alternation, but which also brings ever new demands.

For a long while I have tried to discover in every large factory which I have visited the particular job which from the standpoint of the outsider presents itself as the most tiresome possible. As soon as I found it, I had a full frank talk with the man or woman who performed it and earnestly tried to get self-observational comment. My chief aim was to bring out how far the mere repetition, especially when it is continued through years, is felt as a source of discomfort. I may again point to a few chance illustrations. In an electrical factory with many thousands of employees I gained the impression that the prize for monotonous work belonged to a woman who packs incandescent lamps in tissue paper. She wraps them from morning until night, from the first day of the year to the last, and has been doing that for the last 12 years. She performs this packing process at an average rate of 13,000 lamps a day. The woman has reached about 50,000,000 times for the next lamp with one hand and with the other to the little pile of tissue sheets and then performed the packing. Each lamp demands about 20 finger movements. As long as I watched her, she was able to pack 25 lamps in 42 seconds, and only a few times did she need as many as 44 seconds. Every 25 lamps filled a box, and the closing of the box required a short time for itself. She evidently took pleasure in expressing herself fully about her occupation. She assured me that she found the work really interesting, and that she constantly felt an inner tension, thinking how many boxes she would be able to fill before the next pause. Above all, she told me that there is continuous variation. Sometimes she grasps the lamp or paper in a different way, sometimes the packing itself does not run smoothly, sometimes she feels fresher, sometimes less in the mood for the work, and there is always something to observe and something to think about.

This was the trend which I usually found. In some large machine works I sought for a long time before I found the type of labor which seemed to me the most monotonous. I finally settled on a man who was feeding an automatic machine which was cutting holes in metal strips and who simply had to push the strips slowly forward; only when the strip did not reach exactly the right place, he could stop the automatic machine by a lever. He made about 34,000 uniform movements daily and had been doing that for the past 14 years. But he gave me the same account, that the work was interesting and stimulating, while he himself made the impression of an intelligent workingman. At the beginning, he reported, the work had sometimes been quite fatiguing, but later he began to like it more and more. I imagined that this meant that at first he had to do the work with full attention and that the complex movement had slowly become automatic, allowing him to perform it like a reflex movement and to turn his thoughts to other things. But he explained to me in full detail that this was not the case, that he still feels obliged to devote his thoughts entirely to the work at hand, and that he is able only under these conditions to bring in the daily wage which he needs for his family, as he is paid for every thousand holes. But he added especially that it is not only the wage which satisfies him, but that he takes decided pleasure in the activity itself.

On the other hand, I not seldom found wage-earners, both men and women, who seemed to have really interesting and varied activities and who nevertheless complained bitterly over the monotonous, tiresome factory labor. I became more and more convinced that the feeling of monotony depends much less upon the particular kind of work than upon the special disposition of the individual. It cannot be denied that the same contrast exists in the higher classes of work. We find school-teachers who constantly complain that it is intolerably monotonous to go on teaching immature children the rudiments of knowledge, while other teachers with exactly the same task before them are daily inspired anew by the manifoldness of life in the classroom. We find physicians who complain that one case in their practice is like another, and judges who despair because they always have to deal with the same petty cases, while other judges and physicians feel clearly that every case offers something new and that the repetition as such is neither conspicuous nor disagreeable. We find actors who feel it a torture to play the same rôle every evening for several weeks, and there are actors who, as one of the most famous actresses assured me after the four hundredth performance of her star rôle, repeat their parts many hundred times with undiminished interest, because they feel that they are always speaking to new audiences. It seems not impossible that this individual difference might be connected with deeper-lying psychophysical conditions. I approached the question, to be sure, with a preconceived theory. I fancied that certain persons had a finer, subtler sense for differences than others and that they would recognize a manifoldness of variations where the others would see only uniformity. In that I silently presupposed that the perception of the uniformity must be something disturbing and disagreeable and the recognition of variations something which stimulates the mind pleasantly. But when I came to examine the question experimentally, I became convinced that such a hypothesis is erroneous, and if I interpret the results correctly, I should say that practically the opposite relation exists. Those who recognize the uniformities readily are not the ones who are disturbed by them.

I proceeded in the following way. To make use of a large number of subjects accustomed to intelligent self-observation, I made the first series of experiments with the regular students in my psychology lecture course in Harvard University. Last winter I had more than four hundred men students in psychology who all took part in that introductory series. The task which I put before them in a number of variations was this: I used lists of words of which half, or one more or less than half, belonged to one single conceptional group. There were names of flowers, or cities, or poets, or parts of the body, or wild animals, and so on. The remaining words of the list, on the other hand, were without inner connection and without similarity. The similar and the dissimilar words were mixed. The subjects listened to such a list of words and then had to decide without counting from the mere impression whether the similar words were more or equally or less numerous than the dissimilar words. In other experiments the arrangement was that two different lists were read and that in the two lists a larger or smaller number of words were repeated from the first list. Here, too, the subjects had to decide from the mere impression whether the repeated words were in the majority or not. In every experiment the judgment referred to those words which belonged to the same group and which were in this sense uniform, or to the repeated words, and it had to be stated with reference to them whether their number was larger, equal to, or smaller than the different words. If all replies had been correct, the judgment would have been 40 per cent equal, 30 per cent smaller, and 30 per cent larger, as they were arranged in perfect symmetry. As soon as I had the results from the students, we figured out for every one what number he judged equal, smaller, or greater. Then we divided the equal judgments by 2 and added half of them to the larger and half to the smaller judgments. In this way we were enabled by one figure to characterize the whole tendency of the individual. We found that in the whole student body there was a tendency to underestimate the number of the similar or of the repeated words. The majority of my students had a stronger impression from the varying objects than from those which were in a certain sense equal. Yet this tendency appeared in very different degrees and for about a fourth of the participants the opposite tendency prevailed. They received a stronger impression from the uniform ideas.

I had coupled with these experimental tests a series of questions, and had asked every subject to express with fullest possible self-analysis his practical attitude to monotony in life. Every one had to give an account whether in the small habits of life he liked variety or uniform repetition. He was asked especially as to his preferences for or against uniformity in the daily meals, daily walks, and so on. Furthermore he had to report how far he is inclined to stick to one kind of work or to alternate his work, how far he welcomes the idea that vocational work may bring repetition, and so on. And finally I tried to bring the results of these self-observations into relation with the results of those experiments. It was here that the opposite of the hypothesis which I had presupposed suggested itself to me with surprising force. I found that just the ones who perceive the repetition least hate it most, and that those who have a strong perception of the uniform impressions and who overestimate their number are the ones who on the whole welcome repetition in life.

As soon as I had reached this first experimental result, I began to see how it might harmonize with known psychological facts. Some years ago a Hungarian psychologist[37] showed by interesting experiments that if a series of figures is exposed to the eye for a short fraction of a second, equal digits are seen only once, and he came to the conclusion that equal impressions in such a series inhibit each other. In the Harvard laboratory we varied these experiments by eliminating the spatial separation of those numbers. In our experiments the digits did not stand side by side, but followed one another very quickly in the same place.[38] Similar experiments we made with colors and so on. Here, too, we found that quickly succeeding equal or very similar impressions have a tendency to inhibit each other or to fuse with each other. Where such an inhibition occurs, we probably ought to suppose that the perception of the first impression exhausts the psychical disposition for this particular mental experience. The psychophysical apparatus becomes for a moment unable to arouse the same impression once more.

The above described new experiments suggest to me that this inhibition of equal or similar impressions is found unequally developed in different individuals. They possess a different tendency to temporary exhaustion of psychophysical dispositions. There are evidently persons who after they have received an impression are unable immediately to seize the same impression again. Their attention and their whole inner attitude fails. But there are evidently other persons for whom, on the contrary, the experience of an impression is a kind of inner preparation for arousing the same or a similar impression. In their case the psychophysical dispositions become stimulated and excited, and therefore favor the repetition. If, as in our experiments, the task is simply to judge the existence of equal or similar impressions without any strain of attention, the one group of persons must underestimate the number of the equal impressions because many words are simply inhibited in their minds and remain neglected, the other groups of persons must from their mental dispositions overestimate the number of similar words. From here we have to take one step more. If these two groups of persons have to perform a task in which it is necessary that not a single member of a series of repetitions be overlooked, it is clear that the two groups must react in a very different way. Now a perfect perception of every single member is forced on them. Those who grasp equal impressions easily, and who are prepared beforehand for every new repetition by their inner dispositions, will follow the series without strain and will experience the repetition itself with true satisfaction. On the other hand, those in whom every impression inhibits the readiness to receive a repetition, and whose inner energy for the same experience is exhausted, must feel it as a painful and fatiguing effort if they are obliged to turn their attention to one member after another in a uniform series. This mental torture is evidently the displeasure which such individuals call the dislike of monotony in their work. Whether this theoretical view is correct, we have to determine by future studies. In our Harvard laboratory we have now proceeded from such preparatory mass experiments to subtle investigations on a small number of persons well trained in psychological self-observation with whom the conditions of the experiment can be varied in many directions.[39]

It would seem probable that such experiments might also win psychotechnical significance. A short series of tests which would have to be adapted to the special situations, and which for the simple wage-earner would have to be much easier than those sketched above, would allow it to be determined beforehand whether an individual will suffer from repetition in work. Even if we abstract from arguments of social reform and consider exclusively the economic significance, it must seem important that labor which involves much repetition be performed by men and women whose mental dispositions favor an easy grasp of successive uniform impressions. Experimentation could secure the selection of the fit workmen and the complaint of monotony would disappear. The same selection could be useful in the opposite direction, as many economic occupations, especially in our time of automatic machines, demand a quick and often rhythmical transition from one activity to another. It is evident that those whose natural dispositions make every mental excitement a preparation not for the identical but for the contrasting stimulation will be naturally equipped for this kind of economic tasks.

XVII

The problem of monotony may lead us on to other conditions through which attention is hindered and the product of labor thereby decreased. The psychologist naturally first thinks of external distractions of attention. If he turns to practical studies of the actual economic life, he is often decidedly surprised to find how little regard is given to this psychophysical factor. In industrial establishments in which the smallest disturbance in the machine is at once remedied by a mechanic in order that the greatest possible economic effect may be secured, frequently nobody takes any interest in the most destructive disturbances which unnecessarily occur in the subtlest part of the factory mechanism, namely, the attention apparatus of the laborers. Such an interference with attention must, for instance, be recognized when the workingman, instead of devoting himself to one complex function, has to carry out secondary movements which appear to be quite easily performed and not to hinder him in his chief task. Often his own feeling may endorse this impression. Of course the individual differences in this direction are very great. The faculty of carrying on at the same time various independent functions is unequally distributed and the experiment can show this clearly. It is also well known from practical life that some men can easily go on dictating to a stenographer while they are affixing their signature to several hundred circular letters, or can continue their fluent lecture while they are performing experimental demonstrations. With others such a side activity continually interrupts the chief function. Then some succeed better than others in securing a certain automatism of the accessory function to such a point that its special acts do not come to consciousness at all. For example, I watched a laborer who was constantly engaged in a complicated technical performance, and he seemed to give to it his full attention. Nevertheless he succeeded in moving a lever on an automatic machine which stood near by whenever a certain wheel had made fifty revolutions. During all his work he kept counting the revolutions without being conscious of any idea of number. A system of motor reactions had become organized which remained below the threshold of consciousness and which produced only at the fiftieth recurrence the conscious psychical impulse to perform the lever movement. Yet whether the talent for such simultaneous mastery of independent functions be greater or smaller and the demand more or less complex, in every case the principal action must be hampered by the side issue. To be sure, it may sometimes be economically more profitable to allow the hindrance to the chief work in order to save the expense of an extra man to do the side work. In most cases, however, such a consideration is not involved; it is simply an ignoring of the psychological situation. As the accessory work seems easy, its hindering influence on other functions is practically overlooked. Psychological laboratory experiments have shown in many different directions that simultaneous independent activities always disturb and inhibit one another.

We must not forget that even the conversations of the laborers belong in this psychophysical class. Where a continuous strain of attention has produced a state of fatigue, a short conversation will bring a certain relief and relaxation, and the words which the speaker hears in reply will produce a general stimulation of psychical energy for the moment. Moreover, the mere existence of the social conversational intercourse will raise the general emotional mood, and this feeling of social pleasure may be the source from which may spring new psychophysical powers. Nevertheless the fundamental fact, after all, is that any talking during the labor, so far as it is not necessary for the work itself, surely involves a distraction of attention. Here, too, the individual is not conscious of the effect. He feels certain that he can perform his task just as well, and even the piece-worker, who is anxious to earn as much as possible, is convinced that he does not retard himself by conversation. But the experiments which have been carried on in establishments with scientific management speak decidedly against such a supposition. A tyrannical demand for silence would, of course, be felt as cruelty, and no suggestion of a jail-like discipline would be wise in the case of industrial labor, for evident psychological reasons. But various factories in rearranging their establishments according to the principles of scientific management have changed the positions of the workmen so that conversations become more difficult or impossible. The result reported seems to be everywhere a significant increase of production. The individual concentrates his mind on the task with an intensity which seems beyond his reach as long as the inner attitude is adjusted to social contact. The help which is rendered by the feeling of social coöperation, on the other hand, is not removed by the mere abstaining from speaking. Interesting psychopedagogical experiments have, indeed, demonstrated that working in a common room produces better results than isolated activity. This is not true of the most brilliant, somewhat nervous school children, who achieve in their own room at home more than in the classroom. But for the average, which almost alone is in question for life in the factory, the consciousness of common effort is a source of psychophysical reinforcement. This evidently remains effective when the workingmen can see one another, even if the arrangement of the seats precludes the possibility of chatting during the work.

However, by far the more important cause of distraction of attention lies in those disturbances which come from without. Here again the chief interest ought to be attached to those interferences which the workman himself no longer feels as such. In a great printing-shop a woman who was occupied with work which demanded her fullest attention was seated at her task in an aisle where trucking was done. Removing this operator to a quiet corner caused an increase of 25 per cent in her work.[40] To be sure there are many such disturbances in factory life which can hardly be eliminated with the technical means of to-day. For instance, the noise of the machines, which in many factories makes it impossible to communicate except by shouting, must be classed among the real psychological interferences in spite of the fact that the laborers themselves usually feel convinced that they no longer notice it at all. Still more disturbing are strong rhythmical sounds, such as heavy hammer blows which dominate the continuous noises, as they force on every individual consciousness a psychophysical rhythm of reaction which may stand in strong contrast to that of a man's own work. From the incessant inner struggle of the two rhythms, the one suggested by the labor, the other by the external intrusion, quick exhaustion becomes unavoidable.

If it were our purpose to elaborate a real system of psychological economics, we should have to proceed here to a careful study of the influences of fatigue on the industrial achievement. We should have to discuss the various kinds of fatigue and exhaustion, the conditions of restoration, and the whole group of related problems of psychophysics. But this is the one field which has been thoroughly ploughed over by science and by practical life in the course of the last decades. No new suggestion and no new hint of the importance of the problem is needed here. Our short discussion was planned to be confined to those regions which have not been worked up in systematic investigations and for which new devices seemed desirable. Hence we do not reproduce here the rich material of facts which the physiologists and psychophysicists have brought together in the last half-century, the importance of which for industrial labor is perfectly evident. Moreover, the practical applications and the insight into the social needs have transformed the factories themselves into one big laboratory in which the problem of fatigue has been studied by practical experiments. The problem of the dependence of fatigue and output upon the length of the working day has been tested in numberless places with the methods of really exact research, as it was easy to find out how the achievement of the laborers became quantitatively and qualitatively changed by the shortening of the working hours.

When in one civilized country after another the exhaustingly long working days of the industrial wage-earner were shortened more and more, the theoretical discussions of the legislators and of the social reformers were soon supplemented by careful statistical inquiries in the factories. It was found that everywhere, even abstracting from all other cultural and social interests, a moderate shortening of the working day did not involve loss, but brought a direct gain. The German pioneer in the movement for the shortening of the workingman's day, Ernst Abbé, the head of one of the greatest German factories, wrote many years ago that the shortening from nine to eight hours, that is, a cutting-down of more than 10 per cent, did not involve a reduction of the day's product, but an increase, and that this increase did not result from any supplementary efforts by which the intensity of the work would be reinforced in an unhygienic way.[41] This conviction of Abbé still seems to hold true after millions of experiments over the whole globe. But the problem of fatigue has forced itself on the consideration of the men of affairs from still another side. It has been well known for a long while how intimate the relations are between fatigue and industrial accidents. The statistics of the various countries and of the various industries do not harmonize exactly, but a close connection between the number of accidents and the hours of the day can be recognized everywhere. Usually the greatest number of injuries occurs between ten and eleven o'clock in the forenoon and between three and four o'clock in the afternoon. The different distribution of the working hours, and of the pauses for the meals, make the various statistical tables somewhat incomparable. But it can be traced everywhere that in the first working hours in which fatigue does not play any considerable rôle, the number of accidents is small, and that this number sinks again after the long pauses. It is true that the number also becomes somewhat smaller at the end of the forenoon and of the afternoon period, but this seems to have its cause in the fact that with growing fatigue and with the feeling that the end of the working period is near, the rhythm of the activity becomes much slower, and with such slower movements the danger of accidents is greatly reduced. In a similar way the factories have had to give the fullest attention to the fatigue problem in its relation to the distribution of pauses, and above all in its relation to the advisable speed of the machines, the limits of which are set by the fatigue of the workingmen, and still more of the working-women.

The legislatures, the labor unions, and the manufacturers have then had this problem of fatigue constantly before their eyes.[42] On the other hand, the psychologists and physiologists have continuously studied the fatigue and restoration of the muscle system and of the central nervous system, and have analyzed the facts with the subtlest methods. Yet, in spite of this, it cannot be denied that a real mutual enrichment has so far hardly been in question. On the contrary, the whole situation has again demonstrated the old experience. The mere trying and trying again in practical life can never reach the maximum effects which may be secured by systematic, scientifically conducted efforts. On the other side the studies of the theoretical scholars can never yield the highest values for civilization if the problems which offer themselves in practical life are ignored. The theorists have to prepare the ground, and in this preparatory work they must, indeed, remain utterly regardless of any practical situations. But after that a second stage must be reached at which on the foundation of this neutral research special theoretical investigations are undertaken which originate from practical conditions. As long as industrial managers have no contact with the experiments of the laboratory and the experimentalists are shy of any contact with the industrial reality, humanity will pass through social suffering. The hope of mankind will be realized by the mutual fertilization of knowing and doing.

The practical efforts of the factories have, indeed, not yet reached the point at which the greatest possible achievement which can be reached without over-fatigue may be secured. We called the abbreviation of the working day an experimental scheme. The question of reducing the working hours is so simple that no further special experiments are needed. But when we come to the questions of the pauses at work, the speed of work and similar factors related to fatigue, the situation is by far more complicated, and the often capricious changes in the plant have very little in common with a systematic experiment. Some well-known studies of the efficiency engineers clearly demonstrate the possibility of such systematic efforts. The best-known case is probably Taylor's study of the pig-iron handlers of the Bethlehem Steel Company. He found that the gang of 75 men was loading on the average about 12-1/2 tons per man per day. When he discussed with various managers the question of what output would be the possible maximum, they agreed that under premium work, piecework, or any of the ordinary plans for stimulating the men, an output of 18 to 25 tons would be the extreme possibility. Then he proceeded to a systematic study of the fatigue in its relation to the burden and of the best possible relation between working time and resting time. His first efforts to find formulas were unsuccessful, because he calculated only the actual mechanical energy exerted and found that some men were tired after exerting energy of 1/8 hp., while others seemed to be able to produce the energy of 1/2 hp. without greater fatigue. But soon he discovered the mistake in his figures. He had considered only the actual movements, and had neglected the period in which the laborer was not moving and was not exerting energy, but in which a weight was pulling his arms and demanding a corresponding muscular effort. As soon as this muscular achievement was taken into account, too, he found that for each particular weight a definite relation exists between the time that a man is under a heavy load and the time of rest. For the usual loads of 90 pounds, he found that a first-class laborer must not work more than 43 per cent of time working day and must be entirely without load 57 per cent. If the load becomes lighter, the relation is changed. If the workman is handling a half pig weighing 46 pounds, he can be under load 58 per cent of the day and only has to rest during 42 per cent.[43]

As soon as these figures were experimentally secured, Taylor selected fit men, and did not allow them to lift and to carry the loads as they pleased, but every movement was exactly prescribed by foremen who timed exactly the periods of work and rest. If he had simply promised his men a high premium in case they should carry more than the usual 12 tons a day, they would have burdened themselves as heavily as possible and would have carried the load as quickly as possible, thus completely exhausting themselves after three or four hours of labor. In spite of such senseless exaggeration of effort in the first hours, the total output for the day would have been relatively small. Now the foremen determined exactly when every individual should lift and move the load and when he should sit quietly. The result was that the men, without greater fatigue, were able to carry 47-1/2 tons a day instead of the 12-1/2 tons. Their wages were increased 60 per cent. Such a trivial illustration demonstrates very clearly the extreme difference between an increase of the economic achievement by scientific, experimental investigation and a mere enforcing of more work by artificially whipping-up the mind with promises of extraordinary wages. Yet even such rules as the scientific management engineers have formed, may be elaborated to more lasting prescriptions as soon as the purely psychological factors are brought more into the foreground and are approached with the careful analysis of the experimental psychologist.

Such a systematic psychological inquiry is the more important for questions of fatigue, as we know that the subjective feeling of displeasure in fatigue is no reliable measure for the objective fatigue, that is, for the real reduction of the ability for work. Daily experience teaches us how easily some people overstep the limits of normal fatigue, and in extreme cases even come to a nervous breakdown because nature did not protect them by the timely appearance of strong fatigue feelings. On the other hand, we find many men and still more women who feel tired even after a small exertion, because they did not learn early to inhibit the superficial feelings of fatigue, or because the sensations of fatigue have in fact a certain abnormal intensity in their case. The question how far the psychophysical apparatus has really been exhausted by a certain effort must be answered with the help of objective research and not on the basis of mere subjective feelings. But such objective measurements demand systematic experiments in the laboratory.

The experiments which really have been carried on in the laboratory as yet, as far as they were not merely physiological, have on the whole been confined to so-called mental labor, and were essentially devoted to problems of school instruction or medical diagnosis. We have no doubt excellent experiments which are devoted to the study of the individual differences of exhaustion, fatigue, exhaustibility, ability to recover the lost energy, ability to learn from practice, and so on, but they are still exclusively adjusted to the needs of the school-teacher and of the nerve specialist and would hardly be immediately useful to the manager of a factory. We shall need a long careful series of investigations in order to determine how far those manifold results from experiments with memory work, thought work, writing work, and so on can be applied to the work which the industrial laborer is expected to perform.

XVIII

The increase and decrease of the ability to do good work depends of course not only upon the direct fatigue from labor and the pauses for rest; a large variety of other factors may lead to fluctuations which are economically important. The various hours of the day, the seasons of the year, the atmospheric conditions of weather and climate, may have such influence. Some elements of this interplay have been cleared up in recent years. Just as the experiments of pedagogical psychology have determined the exact curve of efficiency during the period of an hour in school, so other investigations have traced the typical curve of psychical efficiency throughout the day and the year. Sociological and criminological statistics concerning the fluctuations in the behavior of the masses, common-sense experience of practical life, and finally, economic statistics concerning the quantity and quality of industrial output in various parts of the day and of the year, have supplemented one another. The systematic assistance of the psychological laboratory, however, has been confined to the educational aspect of the problem. Psychological experiments have determined how the achievement of the youth in the schoolroom changes with the months of the year and the hours of the day. It seems as if it could not be difficult to secure here, too, a connection between exact experiment and economic work. Much will have to be reduced to individual variations. The laboratory has already confirmed the experience of daily life that there are morning workers whose strongest psychophysical efficiency comes immediately after the night's rest, while the day's work fatigues them more and more; and that there are evening workers who in the morning still remain under the after effects of the night's sleep, and who slowly become fresher and fresher from the stimuli of the day. It would seem not impossible to undertake a systematic selection of various individuals under this point of view, as different industrial tasks demand a different distribution of efficiency between morning and night.

Such a selection and adjustment may be economically still more important with reference to the fluctuations during the course of the year. Economic inquiries, for instance, have suggested that younger and older workingmen who ordinarily show the same efficiency become unequal in their ability to do good work in the spring months, and the economists have connected this inequality with sexual conditions. But other factors as well, especially the blood circulation of the organism and the resulting reactions to external temperature, different gland activities, and so on, cause great personal differences in efficiency during the various seasons of the year. Inasmuch as we know many economic occupations in which the chief demand is made in one or another period of the year, a systematic study of these individual variations might be of high economic value, where large numbers are involved, and might contribute much to the individual comfort of the workers. But a constant relation to day and year also seems to exist independent of all personal variations. When the sun stands at its meridian, a minimum of efficiency is to be expected and a similar minimum is to be found at the height of summer. Correspondingly we have an increase of the total psychical efficiency in winter-time. During the spring-time the behavior seems, as far as the investigations go, to be different in the intellectual and in the psychomotor activities. It is claimed that the efficiency of the intellectual functions decreases as the winter recedes, but that the efficiency of psychomotor impulses increases.[44]

The influences of the daily temperature, of the weather and of the seasons may be classed among the physical conditions of efficiency. We may group with them the effects of nourishment, of stimulants, of sleep, and so on. As far as the relations between these external factors and purely bodily muscle work are involved, the interests of the psychologists are not engaged. But it is evident that every one of these relations also has its psychological aspect, and that a really scientific psychotechnical treatment of these problems can become possible only through the agency of psychological experiments. We have excellent experimental investigations concerning the influence of the loss of sleep on intellectual labor and on simple psychomotor activities. But it would be rather arbitrary to deduce from the results of those researches anything as to the effect of reduction of sleep on special economic occupations. Yet such knowledge would be of high importance. We have in the literature concerned with accidents in transportation numerous popular discussions about the destructive influence of loss of sleep on the attention of the locomotive engineer or of the helmsman or of the chauffeur, but an analysis of the particular psychophysical processes does not as yet exist and can be expected only from systematic experiments. Nor has the influence of hunger on psychotechnical activities been studied in a satisfactory way.

A number of psychological investigations have been devoted to the study of the influence of alcohol on various psychical functions and in this field at least the strictly economic problem of industrial labor has sometimes been touched. We have the much quoted and much misinterpreted experiments [45] which were carried on in Germany with typesetters. The workmen received definite quantities of heavy wine at a particular point in the work and the number of letters which they were able to set during the following quarter-hours were measured and compared with their normal achievement in fifteen minutes. The reduction of efficiency amounted on the average to 15 per cent of the output. It may be mentioned that the loss referred only to the quantity of the work and not at all to the quality. The well-known subjective illusory feeling of the subjects was not lacking; they themselves believed that the wine had reinforced their working power. As soon as such experiments are put into the service of economic life, they will have to be carried on with much more accurate adjustment to the special conditions, with subtler gradation of the stimuli, and especially with careful study of individual factors. But at first it seems more in the interest of the practical task that the extremely complicated problem of the influence of alcohol be followed up by purely theoretical research in the laboratory in order that the effect may be resolved into its various components. We must first find the exact facts concerning the influence of alcohol on elementary processes of mental life, such as perception, attention, memory, and so on, and this will slowly prepare the way for the complete economic experiment.

At present the greatest significance for the economic field may be attached to those alcohol experiments which dealt with the apprehension of the outer world. They proved a reduction in the ability to grasp the impressions and a narrowing of the span of consciousness. The indubitable decrease of certain memory powers, of the acuity in measuring distance, of the time estimation, and similar psychical disturbances after alcohol, must evidently be of high importance for industry and transportation, while the well-known increase of the purely sensory sensibility, especially of the visual acuity after small closes of alcohol, hardly plays an important rôle in practical life. The best-known and experimentally most studied effect of alcohol, the increase of motor excitability, also evidently has its importance for industrial achievements. It cannot be denied that this facility of the motor impulses after small doses of alcohol is not a real gain, which might be utilized economically, but is ultimately an injury to the apparatus, even if we abstract from the retardation of the reaction which comes as an after-effect. The alcoholic facilitation, after all, reduces the certainty and the perfection of the reaction and creates conditions under which wrong, and this in economic life means often dangerous, motor responses arise. The energy of the motor discharge suffers throughout from the alcohol.

Some experiments which were recently carried on with reference to the influence of alcohol on the power of will seem to have especial significance for the field of economic activity. The method applied in the experiment was the artificial creation of an exactly measurable resistance to the will-impulse directed toward a purpose. The experiment had to determine what power of resistance could be overcome by the will and how far this energy changes under the influence of alcohol. For this end combinations of meaningless syllables were learned and repeated until they formed a close connection in memory. If one syllable was given, the mechanical tendency of the mind was to reproduce the next syllable in the memorized series. The will-intention was then directed toward breaking this memory type. For instance, it was demanded, when a syllable was called, that the subject should not answer with the next following syllable, but with a rhyming syllable. This will-impulse easily succeeded when the syllables to be learned had been repeated only a few times, while after a very frequent repetition the memory connection offered a resistance which the simple will-intention could not break. The syllable which followed in the series rushed to the mind before the intention to seek a rhyming syllable could be realized. The number of repetitions thus became a measure for the power of the will. After carrying out these experiments at first under normal conditions, they were repeated while the subjects were under the influence of exactly graded doses of alcohol.[46] From such simple tasks the experiment was turned to more and more complex ones of similar structure. All together they showed clearly that the alcohol did not influence the ability to make the will effective and that the actual decrease of achievement results from a decrease in the ability to grasp the material. As long as the alcohol doses are small, this feeling of decreased ability stirs up a reinforcement in the tension of the will-impulse. This may go to such an extent that the increased will-effort not only compensates for the reduced understanding, but even over-compensates for it, producing an improvement in the mental work. But as soon as the alcohol doses amount to about 100 cubic centimeters, the increased tension of the will is no longer sufficient to balance the paralyzing effect in the understanding. Yet it must not be overlooked that in all these experiments only isolated will acts were in question which were separated from one another by pauses of rest. Evidently, however, the technical laborer is more often in a situation in which not isolated impulses, but a continuous tension of the will is demanded. How far such an uninterrupted will-function is affected by alcohol has not as yet been studied with the exact means of the experiment.

To be sure an obvious suggestion would be that the whole problem, as far as economics, and especially industry, are concerned, might be solved in a simpler way than by the performance of special psychological experiments, namely, by the complete elimination of alcohol itself from the life of the wage-earner. The laboratory experiment which seems to demonstrate a reduction of objective achievement in the case of every important mental function merely supplements in exact language the appalling results indicated by criminal statistics, disease statistics, and inheritance statistics. It seems as if the time had come when scientists could not with a good conscience suggest any other remedy than the merciless suppression of alcohol. Indeed, there can be no doubt that alcohol is one of the worst enemies of civilized life, and it is therefore almost with regret that the scientist must acknowledge that all the psychological investigations, which have so often been misused in the partisan writings of prohibitionists, are not a sufficient basis to justify the demand for complete abstinence.

First, newer experiments make it very clear that many of the so-called effects of alcohol which the experiment has demonstrated are produced or at least heightened by influences of suggestion. Experiments which have been carried on in England for the study of that point show clearly that certain psychical disturbances which seem to result from small doses of alcohol fail to appear as soon as the subject does not know that he has taken alcohol. For that purpose it was necessary to eliminate the odor, and this was accomplished by introducing the beverages into the organism by a stomach pump. When by this method sometimes water and sometimes diluted alcohol was given without the knowledge of the subject, the usual effects of small doses of alcohol did not arise. But another point is far more important. We may take it for granted that alcohol reduces the ability for achievement as soon as such very small doses are exceeded. But from the standpoint of economic life we have no right to consider a reduction of the psychical ability to produce work as identical with a decrease in the economic value of the personality. Such a view would be right if the influence necessarily set in at the beginning of the working period. But if, for instance, a moderate quantity of beer is introduced into the organism after the closing of the working day, it would certainly produce an artificial reduction of the psychical ability, and yet this decrease of psychophysical activity might be advantageous to the total economic achievement of the workingman in the course of the week or the year. To be sure the glass of beer in the evening paralyzes certain inhibitory centres of the brain and therefore puts the mind out of gear, but such a way of expressing it may easily be misleading, as it suggests too much that a real injury is done. From the point of view of scientific psychology, we must acknowledge that such a paralyzing effect in certain parts of the psychophysical system sets in with every act of attention and reaches its climax in sleep, which surely does no harm to the mind. It may be thoroughly advantageous for the total work of the normal, healthy, average workingman if the after effects of the motor excitement of the day are eliminated by a mild, short alcoholic poisoning in the evening. It may produce that narrowing and dulling of consciousness which extinguishes the cares and sorrows of the day and secures the night's sleep, and through it increased efficiency the next morning. Systematic experiments with exact relation to the various technical demands must slowly bring real insight into this complex situation. The usual hasty generalization from a few experiments with alcohol for partisan interests is surely not justified in the present unsatisfactory state of knowledge.[47]

Perhaps we know still less of the influences which coffee, tea, tobacco, sweets, and so on exert on the life of the industrial worker. It will be wise to resolve these stimuli in daily use into their elements and to study the effects of each element in isolated form. To know, for instance, the effects of caffein on the psychophysical activities does not mean to know the effects of tea or coffee, which contain a variety of other substances besides the caffein, substances which may be supposed to modify the effect of the caffein. Yet the first step must in this case be the study of the effects of the isolated caffein, before the total influences of the familiar beverages can be followed up. An excellent investigation of this caffein effect on various psychological and psychomotor functions has recently been completed.[48] When the caffein effect on tapping movements was studied, it was found that it works as a stimulation, sometimes preceded by a slight initial retardation. It persists from one to two hours after doses of from one to three grains and as long as four hours after doses of six grains. The steadiness test showed a slight nervousness after several hours after doses of from one to four grains. After six grains there is pronounced unsteadiness. A complex test in coördination indicated that the effect of small, amounts of caffein is a stimulation and that of large amounts a retardation. Correspondingly the speed of performance in typewriting is heightened by small doses of caffein and retarded by larger doses. In both cases the quality of the performance as measured by the number of errors is superior to the normal result.

The influences of the physiological stimulants have many points of contact with the effects of social entertainment, the significance of which for the economic life is still rather unknown in any exact detail. Many factories in which the labor is noiseless, as in the making of cigars, have introduced gramophone music or reading aloud, and it is easy to understand theoretically that a certain animating effect results, which stimulates the whole psychophysical activity But only the experiment would be able to decide how this stimulation is related, for instance, to the distraction of attention, which is necessarily involved, or how it influences various periods of the work and various types of work, how far it is true that the musical key exerts an exciting or relaxing influence, what intensity and what local position, what rhythm and what duration of such æsthetic stimuli, would bring the best possible economic results. We all have read of the favorable effects which were secured in a factory when a cat was brought into every working-room in which women laborers were engaged in especially fatiguing work. The cat became a living toy for the employees, which stimulated their social consciousness. In not a few plants the reinforced achievement is explained by the social means of entertainment, which have been introduced under the pressure of modern philanthropic ideas. The lounging-rooms with the newspapers and periodicals the clubrooms with libraries, the excursions and dances and patriotic festivities, fill up the reservoir of psychophysical energies. As a matter of course all the social movements which enhance the consciousness of solidarity among the laborers and the feeling of security as to their future development in their career have a similar effect of reinforcing the normal psychical achievement.

As the strongest factor, finally, the direct material interest must be added to these conditions. The literature of political economy is full of discussions of the effect of increase of wages, of the payment of bonuses and premiums, of piece-wages, of promised pensions, and, as far as Europe is concerned, of state insurance. In short, the whole individual financial situation in its relation to the psychophysical achievement of the wage-earner is a favorite topic of economic inquiry. We cannot participate here in these inexhaustible discussions, because all these questions are to-day still so endlessly far from the field of psychological experiments. Nevertheless we ought not to forget the experience through which general experimental psychology has gone in the last few decades. When the first experiments were undertaken in order to deal systematically with the mental life, the friends of this new science and its opponents agreed, on the whole, in the belief that certainly only the most elementary phenomena of consciousness, the sensations and the reactions of impulses, would be accessible to the new method. The opponents naturally compared this modest field with the great problems of the mental totality, and therefore ridiculed the new narrow task as unimportant. The friends, on the other hand, were eager to follow the fresh path, because they were content to gain real exactitude by the experiment at least in these simplest questions. Yet as soon as the new independent workshops were established for the young science, it was discovered that the method was able to open fields in which no one had anticipated its usefulness. The experiments turned to the problems of attention, of memory, of imagination, of feeling, of judgment, of character, of æsthetic experience and so on. It is not improbable that the method of the economic psychological experiment may also quickly lead beyond the more elementary problems, as soon as it is systematically applied, and then it, too, may conquer regions of inquiry in which to-day no exact calculation of the psychological factors seems possible.