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
PHYSICAL AND SOCIAL INFLUENCES ON THE WORKING POWER
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.