Classics in the History of Psychology

An internet resource developed by
Christopher D. Green
York University, Toronto, Ontario

(Return to index)

Psychology and Industrial Efficiency

Hugo Münsterberg (1913)


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 [p. 222] 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 [p. 223] 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 [p. 225] 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 [p. 226] 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 04 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 doses 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 [p. 227] 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 [p. 228] 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 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 [p. 229] 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 [p. 230] 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 [p. 231] 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 [p. 232] 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[sic] 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 [p. 233] 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 [p. 234] 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 re 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 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. [p. 235]

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 held 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 held 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 [p. 236] 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 æesthetic 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.

If such an advance is to be a steady one, the economic psychologist will emancipate himself from the chance question of what problems are at this moment important for commerce and industry and will proceed systematically step by step from those results which the psychological laboratory has yielded under the non-economic points of view. Many previous psychological or psychophysical inquiries almost touch the problems of industrial achievement. For instance, the experiments on imitation, which psychophysicists have carried on in purely theoretical [p. 237] or pedagogical interests, move parallel to industrial experiences. It is well known that the pacemaker plays his r81e not only in the held of sport but also in the factory. The rhythm of one laborer gains controlling importance for the others, who instinctively imitate him. Some plants even have automatically working machines with the special intention that the sharp rhythm of these lifeless forerunners shall produce an involuntary imitation in the psychophysical system. In a similar way many laboratory investigations on suggestion and suggestibility point to such economic processes, and it seems to me that especially the studies on the influence of the ideas of purpose which are being undertaken nowadays in many psychological laboratories may easily be connected with the problems of economic life. We know how the consciousness of the task to be performed has an organizing influence on the system of those psychophysical acts which lead to the goal. The experiment has shown under which conditions this effect can be reinforced and under which reduced. Pedagogical experiments have also shown exactly what influence belongs to the consciousness of the approach to the end of work; the feeling of the nearness of the close heightens the achievement, even of the fatigued subject. It would not be [p. 238] difficult to connect psychophysical experiments of this kind with the problems of the task and bonus system, which is nowadays so much discussed in industrial life. The practical successes seem to prove that the individual can do more with equal effort if he does not stand before an unlimited mass of work of which he has to do as much as possible in the course of the day, but if he is before a definitely determined, limited task with the demand that he complete it in an exactly calculated time. Scientific management has made far-reaching use of this principle, but whether constant results for the various industries can be hoped for from such methods must again be ascertained by the psychological experiment.

These hopes surely will not weaken the interest of the psychologist for those many psychological methods which lie outside of the experimental research. A sociologist, who himself had been a laborer in his earlier life, undertook in Germany last year an inquiry into the psychological status of the laborers' achievement by the questionnaire method.[49] He sent to 8000 workingmen in the mining industries, textile industries, and metal industries, blanks containing 26 questions, and received more than 5000 replies. The questions referred to the pleasure and interest in the work, to preferences, to fatigue, to the thoughts during [p. 239] the work, to the means of recreation, to the attitude toward the wages, to the emotional situation, and so on. The 5000 answers allowed manifold classifications. The various mental types of men could be examined, the influence of the machine, the attitude toward monotony, the changes of pleasure and interest in the work with the age of the laborer, the time at which fatigue becomes noticeable, and so on. Many psychological elements of industrial life thus come to a sharp focus and the strong individual differences could not be brought out in a more characteristic way. Yet, all taken together, even such a careful investigation on a psychostatistical basis strongly suggests that a few careful experimental investigations could lead further than such a heaping-up of material gathered from men who are untrained in self-observation and in accurate reports, and above all who are accessible to any kind of suggestion and preconceived idea. The experimental method is certainly not the only one which can contribute to reforms in industrial life and the reinforcement of industrial efficiency, but all signs indicate that the future will and it the most productive and most reliable.


[44] W. Hellpach: Die geopsychischen Erscheinungen, Wtter, Klima und Landschaft und ihr Einfluss auf das Seelenleben (Leipzig, 1911, p. 176-212.)

[45] Aschaffenburg: Praktische Arbeit unter Alkoholwirkung. (Psychologishe Arbetien -- Kraepelin, vol. 1, 1906.)

[46] Hildebrand: Die Beeinflussung der Willenskraft durch den Alkohol. (Königsberg, 1910.)

[47] For the scientific facts concerning alcohol and bibliography compare: Hugo Hoppe: Die Tatsachen über den Alkohol. (Munich, 1912.)

[48] H. L. Hollingworth: The Influence of Caffein[sic] on Mental and Motor Efficiency. (New York, 1912.)

[49] Levenstein: Die Arbeiter frage. (Munich, 1912.)