Psychology and Industrial Efficiency Part 4

THE ADJUSTMENT OF TECHNICAL TO PSYCHICAL CONDITIONS

Teaching and learning represent only the preliminary problem. The fundamental question remains, after all, how the work is to be done by those who have learned it in accordance with the customs of the economic surroundings and who are accordingly already educated and trained for it. What can be done to eliminate everything which diminishes and decreases efficiency, and what remains to be done to reinforce it. Such influences are evidently exerted by the external technical conditions, by variations of the activity itself, and by the play of the psychical motives and counter-motives. It must seem as if only this last factor would belong in the realm of psychology, but the technical conditions, of which the machine itself is the most important part, and the bodily movements also have manifold relations to the psychical life. Only as far as these relations prevail has the psychologist any reason to study the problem. The purely physical and economic factors of technique do not interest him at all, but when a technical arrangement makes a psychophysical achievement more difficult or more easy, it belongs in the sphere of the psychologist, and just this aspect of the work may become of greatest importance for the total result. In all three of these directions, that is, with reference to the technical, to the physiological, and to the purely psychical, the scientific management movement has prepared the way.

The engineers of scientific management recognized, at least, that no part of the industrial process is indifferent, even the apparently most trivial activity, the slightest movement of arm or hand or leg, became the object of their exact measurement. The stopwatch which measures every movement in fractions of a second has become the symbol of this new economic period. As long as special psychological experiments in the service of industrial psychology are still so exceptional, it may, indeed, be acknowledged that the practical experiments in the service of scientific management have come nearest to the solution of these special psychotechnical problems.

To proceed from without toward the centre, we may begin our review with the physical technique of the working conditions and its relations to the mind. Tue history of technique shows on every page this practical adjustment of external labor conditions to the psychophysical necessities and psychophysical demands. No machine with which a human being is to work can survive in the struggle for technical existence, unless it is to a certain degree adapted to the human nerve and muscle system and to man's possibilities of perception, of attention, of memory, of feeling, and of will.

Industrial technique with its restless improvements has always been subordinated to this postulate. Every change which made it possible for the workingman to secure equal effects with smaller effort or to secure greater or better effects with equal effort counted as an economic gain, which was welcome to the market. For instance, throughout the history of industry we find the fundamental tendency to transpose all activities from the great muscles to the small muscles.

Any activity which is performed with the robust muscles of the shoulder when it can be done with the lower arm, or labor which is demanded from the muscles of the lower arm when it can just as well be carried out by the fingers, certainly involves a waste of psychophysical energy. A stronger psychophysical excitement is necessary in order to secure the innervation of the big muscles in the central nervous system. This difference in the stimulation of the various muscle groups has been of significant consequence for the differentiation of work throughout the development of mankind.[25]

Labor with the large muscles has, for these psychophysical reasons, never been easily combined with the subtler training of the finer muscles. Hence a social organization which obliged the men to give their energy to war and the hunt, both, in primitive life, functions of the strongest muscles, made it necessary for the domestic activities, which are essentially functions of the small muscles, to be carried out by women. The whole history of the machine demonstrates this economic tendency to make activities dependent upon those muscles which presuppose the smallest psychophysical effort. It is not only the smaller effort which gives economic advantage to the stimulation of the smaller muscles, but the no less important circ.u.mstance that the psychophysical after-effect of their central excitement exerts less inhibition than the after-effect of the brain excitement for the big muscles.

But we must not overlook another feature in the development of technique. The machines have been constantly transformed in the direction which made it possible to secure the greatest help from the natural coordination of bodily movements. The physiological organization and the psychophysical conditions of the nervous system make it necessary that the movement impulses flow over into motor side channels and thus produce accessory effects without any special effort. If a machine is so constructed that these natural accessory movements must be artificially and intentionally suppressed, it means, on the one side, a waste of available psychophysical energy, and on the other side it demands a useless effort in order to secure this inhibition. The industrial development has moved toward both the fructification of those side impulses and the avoidance of these inhibitions. It has adjusted itself practically to the natural psychical conditions. Ultimately it is this tendency which shaped the technical apparatus for the economic work until the muscle movements could become rhythmical. The rhythmical activity necessarily involves a psychophysical saving and this saving has been instinctively secured throughout the history of civilization. All rhythm contains a repet.i.tion of movement without making a real repet.i.tion of the psychophysical impulse necessary. In the rhythmical activity a large part of the first excitement still serves for the second, and the second for the third. Inhibitions fall away and the mere after-effect of each stimulus secures a great saving for the new impulse. The history of the machine even indicates that the newer technical development not only found the far-reaching division of labor already in the workshops of earlier centuries, but a no less far-reaching rhythmization of the labor in fine adaptation to the needs of the psychophysical organism, long before the appearance of the machines.

The beginnings of the machine period frequently showed nothing but an imitation of the rhythmical movements of man.[26] To be sure, the later improvements of the machine have frequently destroyed that original rhythm of man's movement, as the movement itself, especially in the electric machines, has become so quick that the subjective rhythmical experience has been lost. Moreover, the rhythmical horizontal and vertical movements were for physical reasons usually replaced by uniform circular movements. But even the most highly developed machine demands human activity, for instance, for the supplying with material; and this again has opened new possibilities for the adjustment of technical mechanism to the economic demand for rhythmical muscle activity. The growth of technical devices has thus been constantly under the control of psychological demands, in spite of the absence of systematic psychological investigations. But the decisive factor was, indeed, that these psychological motives always remained in the subconsciousness of civilization. The improvements were consciously referred to the machine as such, however much the practical success was really influenced by the degree of its adjustment to the mental conditions of the workingmen. The new movements of scientific management and of experimental psychology aim toward bringing this adaptation consciously into the foreground and toward testing and studying systematically what technical variations can best suit the psychophysical status of man.

Those who are familiar with the achievements of scientific management remember that by no means only the complicated procedures on a high level are in question. The successes are often the most surprising where the technique is old, and where it might have been imagined that the experiences of many centuries would have secured through mere common sense the most effective performance. The best-known case is perhaps that of the masons, which one of the leaders of the scientific management movement has studied in all its details.[27] The movements of the builders and the tools which they use were examined with scientific exact.i.tude and slowly reshaped under the point of view of psychology and physiology. The total result was that after the new method 30 masons completed without greater fatigue what after the old methods it would have taken 100 masons to do, and that the total expense for the building was reduced to less than a half in spite of the steady increase of the wages of the laborers. For this purpose it was necessary that exact measurements be made of the height at which the bricks were lying and of the height of the wall on which they must be laid, and of the number of bricks which should be carried to the masons at once. He studied how the trowel should be shaped and how the mortar should be used and how the bricks should be carried to the bricklayers. In short, everything which usually is left to tradition, to caprice, and to an economy which looks out only for the most immediate saving, was on the basis of experiments of many years replaced by entirely new means and tools, where nothing was left to arbitrariness. Yet these changes did not demand any invention or physically or economically new ideas, but merely a more careful adaptation of the apparatus to the psychological energies of the masons. The new arrangement permitted a better organization of the necessary bodily movements, fatigue was diminished, the accessory movements were better fructified, fewer inhibitions were necessary, a better playing together of the psychical energies was secured.

The students of scientific management stepped still lower in the scale of economic activity. There is no more ordinary productive function than shoveling. Yet in great establishments the shoveling of coal or of dirt may represent an economically very important factor. It seems that up to the days of scientific management, no one really looked carefully into the technical conditions under which the greatest possible economic effect might be reached. Now the act of shoveling was approached with the carefulness with which a scholar turns to any subtle process in his laboratory. The brilliant originator of the scientific management movement, who carried out these investigations[28]

in the great Bethlehem Steel Works, where hundreds of laborers had to shovel heavy iron ore or light ashes, found that the usual chance methods involve an absurd economic waste. The burden was sometimes so heavy that rapid fatigue developed and the movements became too slow, or the lifted ma.s.s was so light that the larger part of the laborer's energies remained unused. In either case the final result of the day's work must be anti-economic. He therefore tested with carefully graded experiments what weight ensured the most favorable achievement by a strong healthy workingman. The aim was to find the weight which would secure with well-arranged pauses the maximum product in one day without over-fatigue. As soon as this weight was determined, a special set of shovels had to be constructed for every particular kind of material. The laborers were now obliged to operate with 10 different kinds of shovels, each of such a size that the burden always remained an average of 21 pounds for any kind of material. The following step was an exact determination of the most favorable rapidity and the most perfect movement of shoveling, the best distribution of pauses, and so on, and the final outcome was that only 140 men were needed where on the basis of the old plan about 500 laborers had been engaged. The average workingman who had previously shoveled 16 tons of material, now managed 59 tons without greater fatigue. The wages were raised by two thirds and the expenses for shoveling a ton of material were decreased one half This calculation of expenses included, of course, a consideration of the increased cost for tools and for the salaries of the scientific managers.

Whoever visits factories in which the new system has been introduced by real specialists must be surprised, indeed, by the great effects which often result from the better psychophysical adaptation of the simplest and apparently most indifferent tools and means. As far as the complicated machines are concerned, we are accustomed to a steady improvement by the efforts of the technicians and we notice it rather little if the changes in them are introduced for psychological instead of the usual physical reasons. But the fact that even the least complicated and most indifferent devices can undergo most influential improvements, as soon as they are seriously studied from a psychological point of view, remains really a source for surprise.

Sometimes no more is needed than a change in the windows or in the electric lamps, by which the light can fall on the work in a psychologically satisfactory way; sometimes long series of experiments have to be made with a simple hammer or knife or table. Often everything must be arranged against the wishes of the workingmen, who feel any deviation from the accustomed conditions as a disturbance which is to be regarded with suspicion. In one concern I heard that the scientific manager became convinced that all the working-chairs for the women were too low and that the laborers therefore had to hold their arms in a psychophysically unfavorable position during the handling of the apparatus. All were strongly opposed to the introduction of higher chairs. The result was that the manager arranged for the chairs to be raised a few millimeters every evening, without the knowledge of the working-women, as soon as the factory was empty. After a few weeks the chairs had reached the right height without those engaged in the work having noticed it at all. The outcome was a decided increase of efficiency.

But the most rational scheme will after all be to prepare for such arrangements of tools and apparatus by systematic experiments in the psychological laboratory. The subtlety of such investigations will lead far beyond the point which is accessible to the attempts of scientific management. Exact experiments on attention, for instance, will have to determine how the various parts of the apparatus are to be distributed best in s.p.a.ce if the laborer must keep watch for disturbances at various places. Only the laboratory experiment can find the most favorable speed of the machine or can select the muscles to which the mind can send the most effective impulses. The construction of the machine must then be adapted to such results. In the Harvard laboratory, for instance, a practical question led us to examine which fingers would allow the quickest alternation of key movements.[29] If any two of the ten fingers perform for ten seconds the quickest possible alternation of motion, as in a trill, the experiment can demonstrate exactly the differences between the various combinations of fingers and the individual fluctuations for these differences. With an electrical registration of the movements of the alternating fingers we studied in hundredths of a second the time for the motions of two hands and of fingers of the same hand, in order to adjust the keys of a certain machine to the most favorable impulses.

We approach this group of problems from another side when we test the relations of various kinds of machines to various mental types.

Psychologists have studied, for example, the various styles of typewriting machines.[30] From a purely commercial point of view the merits of one or another machine are praised as if they were advantageous for every possible human being. The fact is that such advantages for one may be disadvantages for another on account of differences in the mental disposition. One man may write more quickly on one, another on another machine. As every one knows, the chief difference is that of the keyboard and that of the visible or invisible writing. Machines like the Remington machine work with a shift key; that is, a special key must be pressed when capital letters are to be written. Other machines like the Oliver even demand double shifting, one key for the capital letters, and one for the figures, and so on. On the other hand, machines like the Smith Premier have no shift key, but a double keyboard. It is evident that both the shift-key arrangement and the double keyboard have their particular psychological advantages.

The single alphabet demands much less from the optical memory, and the corresponding motor inner att.i.tude of consciousness is adjusted to a smaller number of possibilities. But the pressure on the shift key, which goes with the single alphabet, is not only a time-wasting act; from the psychological point of view it is first of all a very strong interruption of the uniform chain of impulses. If the capital and small letters are written for a minute alternatingly with the greatest possible speed, the experiment shows that the number of letters for the machine with the double alphabet is about three times greater than for the machine with simple alphabet and shift key. Both systems accordingly have their psychological advantages and disadvantages.

Human beings of distinct visual ideational type or of highly developed motor type will prefer the double alphabet, provided, of course, that the touch system of writing is learned, and this will be especially true if their inner att.i.tude is easily disturbed by interruptions. But those who have a feebly developed optical mental centre and who have small ability for the development of complex motor habits will be more efficient on the machines with the single alphabet, especially if their nervous system is little molested by interruptions and thus undisturbed by the intrusion of the shift key act.

In a similar way the visibility of the writing will be for certain individuals the most valuable condition for quick writing, while for others, who depend less upon visual support, it may mean rather a distraction and an interference with the speediest work. The visible writing attracts the involuntary attention, and thus forces consciousness to stick to that which has been written instead of being concentrated on that which is to be produced by the next writing movements. The operator himself is not aware of this hindrance. On the contrary, the public will always be inclined to prefer the typewriters with visible writing, because by a natural confusion the feeling arises that the production of the letter is somewhat facilitated, when the eye is cooperating, just as in writing with a pen we follow the lines of the written letter. But the situation lies differently in the two cases. When we are writing with a pen, the letter grows under our eyes, while in the machine writing we do not see any part of the letter until the whole movement which produces the single letter is finished. By such a misleading a.n.a.logy many a man is led to prefer the typewriter with visible writing, while he would probably secure a greater speed with a machine which does not tempt him to attend the completed letters, while his entire attention ought to belong to the following letters.

These last observations point to another psychological aspect of the machine and of the whole technical work, namely, their relations to the impressions of the senses. The so-called dynamogenic experiments of the psychological laboratory have demonstrated what a manifold influence flows from the sense-impressions to the will-impulses. If the muscle contraction of a man's fist is measured, the experiment shows that the strongest possible pressure may be very different when the visual field appears in different colors, or tones of different pitch or different noises are stimulating the ear, and so on. As yet no systematic experiments exist by which such results can be brought into relation to the sense-stimuli which reach the laborer during his technical work. The psychophysical effect of colors and noises has not been fructified at all for industrial purposes. The mere subjective judgment of the workingman himself cannot be acknowledged as reliable in such questions. The laborer, for instance, usually believes that a noise to which he has become accustomed does not disturb him in his work, while experimental results point strongly to the contrary. In a similar way the effect of colored windows may appear indifferent to the workmen, and yet may have considerable influence on his efficiency. Numberless performances in the factory are reactions on certain optical or acoustical or tactual signals. Both the engineer and the workman are satisfied if such a signal is clearly perceivable.

The psychological laboratory experiment, however, shows that the whole psychophysical effect depends upon the character of the signal; a more intense light, a quicker change, a higher tone, a larger field of light, a louder noise, or a harder touch may produce a very different kind of reaction.

With a careful time-measurement of the motions, it can often be directly traced how purely technical processes in the machine itself influence and control the whole psychical system of impulses in the man. I observed, in a factory, for instance, the work at a machine which performed most of its functions automatically. It had to hammer fine grooves into small metal plates. A young laborer stood before every such machine, took from a pile, alternately from the right and from the left, the little plates to be serrated, placed them in the machine, turned a lever to bring the hammer into motion, and then removed the serrated plates. The speed of the work was dependent upon the operative, as he determined by his lever movement the instant at which the automatic serrating hammer should be released. The man's activity demanded 9 independent movements. I found that those who worked the most quickly were able to carry out this labor for hours at a uniform rapidity of 4 to 4-1/2 second for those 9 movements. But the time-measurement showed that even these fastest workers were relatively slow in the first 5 movements which they made while the machine stood quiet, and that they reached an astonishing quickness of movement in the 4 last actions during which at the same time the serrating hammer in bewildering rapidity was beating on the plate with sharp loud cracks. The hammer reinforced the energy of the young laborers to an effectiveness which could never have been attained by mere voluntary effort.

Often the simplicity or complication of the stimulus may be decisive in importance, and this also holds true where the most elementary reactions are involved, for instance, the mere act of counting which enters into many industrial functions. Experiments carried on in my laboratory[31] have shown that the time needed to count a certain number of units becomes longer as soon as the units themselves become more complicated. Their inner manifoldness exerts a r.e.t.a.r.ding influence on the eye as it moves from one figure to another. A certain psychical inhibition arises; the mind is held back by the complexity of the impression and cannot proceed quickly enough to the next.

Psychologically no less important is the demand that the external technical conditions so far as they influence consciousness, should remain as far as possible the same, if the same psychical effect is desired, because then only can a perfectly firm connection between stimulus and movement be formed. In technical life this demand is much sinned against. A typical case is that of the signals for which the engineer on the locomotive has to watch. In the daytime the movable arms of the semaph.o.r.e indicate by their horizontal, oblique, or vertical position whether the tracks are clear. At night-time, on the other hand, the same information reaches him by the different colors of the signal lanterns. From a psychical point of view it is probable that the safety of the service would be increased if an unchangeable connection between signal and movement were formed. It would be sufficient for that purpose if the color signals at night were given up and were replaced by horizontal, oblique, or vertical lines of white light or rows of points. Successful experiments of this kind have been carried on by psychologists in the service of this railroad problem.[32]

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 exact.i.tude 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 antic.i.p.ate 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 st.i.tches, measuring the time and the character of the right hand movements for 50 st.i.tches 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 st.i.tches, 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 ECONOMY OF MOVEMENT

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 s.p.a.ce-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 j.a.panese 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 advertis.e.m.e.nt 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 exact.i.tude 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 role 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 att.i.tude 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 exact.i.tude of a simple arm movement seems to increase in the first ten seconds, then rapidly to decrease.

The emotional att.i.tude, 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 exact.i.tude. In experiments extending over many months, which were carried on through the changing emotional att.i.tudes 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 exact.i.tude.[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 exact.i.tude 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 exact.i.tude 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 repet.i.tions in the minute, while for a hand movement of 1 centimeter the average remained nearest to the standard at about 40 repet.i.tions. 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 pa.s.s 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

EXPERIMENTS ON THE PROBLEM OF MONOTONY

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, aesthetic, 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, role 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 repet.i.tion 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 repet.i.tion 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 att.i.tude 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.

Let us not forget that the outsider can hardly ever judge when work offers or does not offer inner manifoldness. If we do not know and really understand the subject, we are entirely unable to discriminate the subtler inner differences. The shepherd knows every sheep, though the pa.s.ser-by has the impression that they all look alike. This inability to recognize the differences which the man at work feels distinctly shows itself even in the most complicated activities. The naturalist is inclined to fancy that the study of a philologist must be endlessly monotonous, and the philologist is convinced that it must be utterly tiresome to devote one's self a life lone to some minute questions of natural science. Only when one stands in the midst of the work is he aware of its unlimited manifoldness, and feels how every single case is somehow different from every other.

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 att.i.tude. 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 repet.i.tion. 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 repet.i.tion, especially when it is continued through years, is felt as a source of discomfort. I may again point to a few chance ill.u.s.trations. 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 a.s.sured 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 cla.s.ses 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 cla.s.sroom.

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 repet.i.tion as such is neither conspicuous nor disagreeable. We find actors who feel it a torture to play the same role every evening for several weeks, and there are actors who, as one of the most famous actresses a.s.sured me after the four hundredth performance of her star role, 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 partic.i.p.ants 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-a.n.a.lysis his practical att.i.tude to monotony in life. Every one had to give an account whether in the small habits of life he liked variety or uniform repet.i.tion. 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 repet.i.tion, 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 repet.i.tion 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 repet.i.tion 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.