THE BEST POSSIBLE WORK
XIII
LEARNING AND TRAINING
We have placed our psychotechnical interest at the service of economic
tasks. We therefore had to start from the various economic purposes
and had to look backward, asking what ways might lead to these goals.
All our studies so far were in this sense subordinated to the one task
which ought to be the primary one in the economic world, and yet which
has been most ignored. The purpose before us was to find for every
economic occupation the best-fitted personality, both in the interest
of economic success and in the interest of personal development.
Individual traits under this point of view become for us the decisive
psychological factors, and experimental psychology had to show us a
method to determine those personal differences and their relation to
the demands for industrial efficiency. This first goal may be reached
with all the means of science, as we hope it will be in the future, or
everything may be left to unscientific, haphazard methods as in the
past: in any case a second task stands before the community, namely,
the securing of the best possible work from every man in his place.
Indeed, the nation cannot delay the solution of this second problem
until the first has been solved in a satisfactory way. We might even
say that the answer to the second question is the more important, the
less satisfactory the answer to the first is. If every place in the
economic world were filled only by those who are perfectly adapted by
their mental traits, it would be much less difficult to get efficient
work from everyone. The fact that so many misfits are at work makes it
such an urgent necessity to find ways and means by which the
efficiency can be heightened.
It must be acknowledged, however, that the problem of the best work is
not quite such a clear one as that of the best man. From various
standpoints a different answer may be given to the question which kind
of work is the best. A capitalistic, profit-seeking egotism may
consider the quickest performance, or, if differences of quality are
involved, the most skillful performance, the only desirable end. The
social reformers, on the other hand, may consider the best work that
which combines the greatest and best possible output with the highest
possible saving of the organism and the fullest development of the
personality. We have emphasized from the start that the practical
psychologist as such has not the right to give a decision upon
problems of social civilization. He has to accept the economic tasks
from the community for which he is working and his impartial service
commences only when the goals have been determined. It is not his
share to select the ends, but simply to determine the means after the
valuable ends have been chosen. As a psychological scientist he has
not the right to enter into the arena of different social party
fights. Yet we find after all a broad region which seems rather
untouched by any conflict of reasonable opinions. A reckless
capitalism on the one side and a feeble sentimentality on the other
side may try to widen or to narrow the boundaries of this region, but
taken all together, a vigorous healthy nation which is eagerly devoted
to its work is on the whole in agreement as to the essential economic
demands for efficient labor.
Experience, to be sure, shows that great changes in the conditions of
work can never enter into the history of civilization without certain
disturbances, and that opposition must therefore necessarily arise in
certain groups even against such changes as are undoubtedly
improvements and advances from the point of view of the whole nation.
Such dissatisfaction arose when the factory system was introduced, and
it is only natural that some irritation should accompany the
introduction of psychological improvements in the methods of work,
inasmuch as not a few wage-earners may at first have to lose their
places because a small number of men will under the improved
conditions be sufficient for the performance of tasks which needed
many before. But the history of economics has clearly shown that from
the point of view of the whole community such an apparent disturbance
has always been only temporary. If the psychologists succeed in
fundamentally improving the conditions of labor, the increased
efficiency of the individual will promote such an enriched and
vivified economic life that ultimately an increase in the number of
laborers needed will result. The inquiry into the possible
psychological contributions to the question of reinforced achievement
must not be deterred by the superficial objection that in one or
another industrial concern a dismissal of wage-earners might at first
result. Psychotechnics does not stand in the service of a party, but
exclusively in the service of civilization.
To begin at the beginning, we may start from the commonplace that
every form of economic labor in the workshop and in the factory, in
the field and in the mine, in the store and in the office, must first
be learned. How far do the experiments of the psychologist offer
suggestions for securing the most economic method of learning
practical activities? Bodily actions in the service of economic work
are taught and learned in hundreds of thousands of places. It is
evident that one method of teaching must reach the goal more quickly
and more reliably than another. Some methods of teaching must
therefore be economically more advantageous, and yet on the whole the
methods of teaching muscular work are essentially left to chance. It
is indeed not difficult to observe how factory workers or artisans
have learned the same complex motion according to entirely different
methods. The result is that they carry out the various partial
movements in a different order, or with different auxiliary motions,
or in different positions, or in a different rhythm, or with different
emphasis, simply because they imitate different teachers, and because
no norm, no certainty as to the best methods for the teaching, has
been determined. But the process of learning is still more fluctuating
and still more dependent upon chance than the process of teaching. The
apprentice approaches the instruction, in any chance way, and the
beginner usually learns even the first steps with a psychophysical
attitude which is left to accident. An immense waste of energy and a
quite anti-economic training in unfit movements is the necessary
result.
The learning of the elements of school knowledge in the classroom in
earlier times proceeded after exactly such chance methods. Any one who
knew how to read, write, and calculate felt himself prepared to pour
reading, writing, and arithmetic into the unprotected children.
Methods which are based on scientific examination of the
psychophysical process of reading and writing were not at the disposal
of the schools, and exact results from comparative studies of
pedagogical methods had not been secured. The last few decades have
created an entirely new foundation for enlightened school work. The
experimental investigations of pedagogical psychology have determined
exactly how the consciousness of the child reacts on the various
methods of teaching and have built up a real systematic economic
learning. All which was left to dilettantic caprice has been
transformed into more or less definite standard forms. For instance,
the old scheme of teaching reading by the alphabet method is
practically eliminated from our modern schools. It is clear that this
learning of the names of the single letters as a starting-point for
the reading of words was not only a wasting of time and energy, but an
actual disturbance in the development of the reading process in the
older generation. As those names of the letters do not occur at all in
the words to be read, but only their sounds, what had been learned in
seeing the single letters had to be inhibited in pronouncing the whole
word. It seems not too much to say that the learning of industrial
activities on the whole still stands on the level of such alphabet
methods, and this cannot be otherwise, as the real problem, namely,
the systematic investigation of the psychophysical activities
involved, has never been brought into the psychological laboratory.
The pedagogical experiment has shown clearly enough that the
subjective feeling of easier or quicker learning may be entirely
unreliable and misleading. If the task is to learn a page by heart, we
may proceed after many different methods. We may learn very small
fractions of the text, repeating only a few words, or we may read
whole paragraphs every time; we may repeat the whole material again
and again, or we may put in long periods of rest after a few
repetitions; we may frequently recite it from memory and have some one
to prompt us; we may give our attention especially to the meaning of
the words, or merely to the sounds, or we may introduce any number of
similar variations. Now the careful experiment shows that of two such
methods one which appears to us the better and more appropriate in
learning, perhaps even as the easier and more comfortable, may prove
itself the less efficient one in the practical result. The psychology
of learning, which won its success by introducing meaningless
syllables as experimental material, has slowly determined the most
reliable methods for impressing knowledge on memory. Where such
results have once been secured, it would surely be a grave mistake
simply to stick to the methods of so-called common sense and to leave
it to the caprice of the individual teacher to decide what method of
learning he will suggest to his pupils. The best method is always the
only one which should be considered. The psychology of economic work
must aim toward similar goals. We must secure a definite knowledge as
to the methods by which a group of movements can best be learned. We
must understand what value is to be attached to the repetitions and to
the pauses, to the imitations and to the special combinations of
movements, to the exercise in parts of the movements, to the rhythm of
the work, and to many similar influences which may shape the learning
process.
The simplest aspect, that of the mere repetition of the movement, has
frequently been examined by psychophysicists. The real founder of
experimental psychology, Fechner, showed the way; he performed
fatiguing experiments with lifted dumb-bells. Then came the time in
which the laboratories began to make a record of the muscular
activities with the help of the ergograph, an instrument with which
the movements of the arm and the fingers can easily be registered on
the smoked surface of a revolving drum. The subtlest variations of the
activity, the increase and decrease of the psychomotor impulse, the
mental fatigue, can be traced exactly in such graphic records. This
psychomotor side of the process, and not the mere muscle activity as
such, is indeed the essential factor which should interest us. The
results of exercise are a training of the central apparatus of the
brain and not of the muscular periphery. The further development of
those experiments soon led to complex questions, which referred not
only to the mere change in the motor efficiency, but to the learning
of particular groups of movements and to the influences on the
exactitude and reliability of the movements. The purely mental factors
of the will-impulse, especially the consciousness of the task, came
into the foreground. These experiences of the scientists concerning
the influences of training, the mechanization of repetition, and the
automatization of movements have been thoroughly discussed by a
brilliant political economist[19] as an explanation of certain
industrial facts, but they have not yet practically influenced life in
the factory.
The nearest approach from the experimental side to the study of the
effect of training in actual industrial tasks may be found in certain
laboratory investigations which refer to the learning of telegraphing,
typewriting, and so on. For instance, we have a careful study[20] of
the progress made in learning telegraphy, both as to the transmitting
of the telegrams by the key movement and the receiving of the
telegrams by the ear. It was found that the rapidity of transmitting
increases more rapidly and more uniformly than the rapidity of
receiving. But while the curve of the latter rises more slowly and
more irregularly, it finally reaches the greater height. The ability
in transmitting, represented by a graphic record, shows an ascent
which corresponds to the typical, steady curve of training. In the
receiving curve, on the other hand, we find not far from the beginning
a characteristic period during which no progress whatever can be
noticed, and this is also repeated at a later stage. The psychological
analysis shows that the increase of ability in the receiving of
telegrams depends upon the development of a complex system of
psychophysical habits. The periods in which the curve does not ascend
represent stages of training in which the elementary habits are
almost completely formed, but have not become sufficiently automatic.
The attention is therefore not yet ready to start habits of a higher
order. The lowest correlation refers to the single letters, after that
to the syllables and words. As soon as the apprentice has reached this
point, he stops, because he must learn to master more and more new
words until his telegraphic vocabulary is large enough to make it
possible for him to turn his consciousness to whole groups of words at
once. Only when this new habit has been made automatic by a training
of several months can he advance to a level at which whole groups of
words are perceived as telegraphic units. A time follows in which this
mastery of whole phrases advances rapidly, until a new period of rest
comes, from which, only after years and often quite suddenly, a last
new ascent can be noticed. Instead of concentrating the attention with
conscious strain on single phrases, the operator progresses to a
perfect liberty in which whole sentences are understood automatically.
We also have a model experimental research into the psychological
conditions of learning in the case of writing on a typewriter.[21] By
electrical connections between the typewriting machine and a system of
levers which registered their movements on the rotating drum of a
kymograph, graph, each striking of a key, each completion of a word,
or of a line, could be recorded in exact time-relations. Each glance
at the copy was also registered. It was found that the process of
learning consisted first of a continuous simplification of the
cumbersome methods with which the beginner commences. A steady
elimination of unfit movements, a selection, a reorganization, and
finally, a combination of psychophysical acts to impulses of higher
order, could be traced exactly. Here, too, the curve of learning at
first rises quickly and then more and more slowly. Of course the usual
fluctuations in the growth of the ability can also be found, and above
all the irregular periods of rest in which the learning itself does
not progress, for some of these so-called plateaus which lie between
the end of one ascent and the beginning of the next may cover a month
and more. At the beginning we have the elementary association between
the single letter and the position of the corresponding key, but soon
an immediate connection between the visual impression of the whole
syllable or the whole word and the total group of movements necessary
to strike the keys for it is developed. The more the ability grows,
the more these psychical impulses of higher order become organized
without conscious intention. The study shows that this development of
higher habits has already begun before the lower habits are fully
settled.
How far the special training involves at the same time a general
training which could be of advantage for other kinds of labor has not
yet been studied at all with reference to industrial technique. There
we are still completely dependent upon certain experiences in the
field of experimental pedagogy, and upon certain statistics, for
instance, in the textile industry. Many patient investigations, with
every independent group of apparatus and machines, may be necessary
before psychotechnics will be able to supply industry with reliable
advice for teaching and learning. Nor have we the least right hastily
to carry over the results from one group of movements to another. Even
where superficially a certain similarity between the technical factors
exists, the psychophysical conditions may be essentially different. In
the two cases mentioned, for instance, telegraphing and typewriting,
the chief factor seems the same, as in both cases the aim is to make
the quickest possible finger movements for purposes of signals; and
yet it is not surprising that the development of the ability from the
beginnings to the highest mastery is rather unlike, as all the
movements in telegraphing are performed with the same finger, while
in typewriting the chief trait is the organization of groups from the
impulses to all ten fingers. At least it is certain that learning
always means far more than a mere facilitation of the movement by
mechanical repetition, and this is true of the simplest handling of
the tools in the workshop, of the movements at the machine in the
factory, and of the most complex performances at the subtlest
instruments. The chief factor in the development is always the
organization of the impulses by which the reactions which are at first
complicated become simplified, later mechanized, and finally
synthesized into a higher group which becomes subordinated to one
simple psychical impulse. The most reliable and psychophysically most
economic means for this organization will have to be studied in the
economic psychological laboratories of the future for every particular
technique. Then only can the enormous waste of psychical energy
resulting from haphazard methods be brought to an end.
A problem which is still too little considered in industrial life is
the mutual interference of acquired technical activities. If one
connected series of movements is well trained by practice, does it
become less firmly fixed, if another series is studied in which the
same beginning is connected with another path of discharge? I
approached this psychophysical question of learning by experiments
which I carried on for a long while with variations of ordinary habits
of daily life, asking whether a habit associated with a certain
sensory stimulus can function automatically while dispositions for a
different habit, previously acquired, remain in the psychophysical
system. For instance, I was accustomed to carry my watch in my
left-hand vest pocket. For a week I carried it in the right-hand
pocket of my trousers and recorded every case in which I first
automatically made the movement to the vest. After some time the
movement to the right-hand pocket became entirely automatic. When it
was sufficiently fixed, I again put the watch in the left-hand vest
pocket and recorded how often I unconsciously grasped at the right
side when I wanted to see what time it was. As soon as the vest pocket
movement had again become fixed, I went back to the right-hand
trousers pocket. And so I alternated for a long while, always changing
only after reaching complete automatism. But the results in this case
and in other similar experiments which I carried on showed that the
new automatic connection did not extinguish the after effects of the
previous habit. With every new change the number of wrong movements
became smaller and smaller, and finally a point was reached at which
the dispositions for both movements were equally developed so that no
wrong movements occurred when the watch was put into the new
position.[22]
This problem has been followed up very recently in a valuable
investigation at Columbia University,[23] in which various habits of
typewriting and of card-sorting were acquired and studied in their
mutual interference. These very careful experiments also show that
when two opposing associations are alternately practiced, they have an
interference effect on each other, but that the interference grows
less and less as the practice effect becomes greater. The interference
effect is gradually overcome and both opposing associations become
automatic, so that either of them can be called up independently
without the appearance of the other. Many details of the research
suggest that this whole group of interference problems deserves the
most careful attention by those who would practically profit from
increased industrial efficiency.
Finally, in the experimental study of the problem of technical
learning, we cannot ignore the many side influences which may hasten
or delay, improve or disturb, the acquisition of industrial skill. In
the Harvard laboratory, for instance, we are at present engaged in an
investigation which deals with the influence of feelings on the
rapidity with which new movement coördinations are mastered.[24] In
order to have unlimited comparable material a very simple technical
performance is required, namely, the distribution of the 52
playing-cards into 52 boxes. Labels on the boxes indicate changing
combinations for the distribution to be learned. We examine, on the
one side, the influence of feelings of comfort or of discomfort on the
learning of the new habit, these feeling states being produced by
external conditions, such as pleasant or unpleasant sounds, odors, and
so on. On the other side we trace the effects of those feelings which
arise during the learning process itself, such as feelings of
satisfaction with progress, or disappointment, or discomfort, or
disgust or joy in the activity.
XIV
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 circumstance 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 coördination 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
repetition of movement without making a real repetition 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 exactitude 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 mass 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 space 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 attitude 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 attitude 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 coöperating, 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 analogy 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 retarding
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 semaphore 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 exactitude with
which the savings of a factory budget can be proven. The profusion of
small attractive devices which automatically perform the economic
household labor and disburden the human workers must not hide the fact
that the chief activities are still little adjusted to the
psychophysical conditions. The situation is similar to that of the
masons, whose function has also been performed for thousands of years,
and yet which did not find a real adaptation to the psychical factors
until a systematic time-measuring study was introduced. A manufacturer
who sells an improved pan or mixing-spoon or broom expects success if
he brings to the market something the merits of which are evident and
make the housewife anticipate a decrease of work or a simplification
of work, but the development of scientific management has shown
clearly that the most important improvements are just those which are
deduced from scientific researches, without at first giving
satisfaction to the laborers themselves, until a new habit has been
formed.
Perhaps the most frequent technical activity of this simple kind is
sewing by hand, which is still entirely left to the traditions of
common sense, and yet which is evidently dependent upon the interplay
of many psychical factors which demand a subtle adaptation to the
psychical conditions. To approach, at least, this field of human labor
a careful investigation of the psychophysics of sewing has been
started in my laboratory.[33] The sewing work is done, with the left
hand supported, and the right hand connected with a system of levers
which make a graphic record of every movement on the smoked surface of
a revolving drum. For instance, we begin with simple over and over
stitches, measuring the time and the character of the right hand
movements for 50 stitches under a variety of technical conditions. The
first variation refers to the length of the thread. The thread itself,
fixed at the needle's eye, varied between 3 feet and 6 inches in
length. Other changes refer to the voluntary speed, to the number of
stitches, to fatigue, to external stimuli, to attention, to methods of
training, and so on, but the chief interest remains centred on the
psychical factors. We are still too much at the beginning already to
foresee whether it will be possible to draw from these psychophysical
experiments helpful conclusions. The four young women engaged in this
laboratory research will later extend it to the psychological
conditions of work with the various types of sewing-machines.
XV
THE 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 space-and
time-relations and the necessary effort. From here he turned to the
application of well-known psychophysical principles. A movement is
less fatiguing and therefore economically most profitable if it occurs
in a direction in which the greatest possible use of gravitation can
be made If both hands have to act at the same time, the labor can be
carried out most quickly and with the smallest effort if corresponding
muscle groups are at work and this means if symmetrical movements are
performed. If unequal movements have to be made simultaneously, the
effort will become smaller if they are psychically bound together by a
common unified impulse. The distance which has to be overcome by
hands, arms, or feet must be brought to a minimum for each partial
movement. Most important, however, is this rule. If a definite
combination of movements has been determined as economically most
suitable, this method must be applied without any exception from the
beginning of the learning. The point is to train from the start those
impulse combinations which can slowly lead to the quickest and best
work. The usual method is the opposite. Generally the beginner learns
to produce from the beginning work which is as good and correct as
possible. In order to produce such qualitatively good results at an
early stage, it is left to him to choose any groups of movements which
happen to be convenient to him. Then these become habitual, and as
soon as he tries to go on to quicker work, these chance habits hinder
him in his progress. The movements which may be best suited for fair
production by a beginner may be entirely unsuited for really quick
work, such as would be expected from an experienced man. The laborer
must replace the first habits which he has learned by a new set,
instead of starting in the first place with motions which can be
continued until the highest point of efficiency has been reached,
even if this involves rather a poor showing at the beginning. A final
maximum rapidity must be secured from the start by the choice of those
motions which have been standardized by careful experiments.
It is also psychophysically important to demand that the movements
shall not be suddenly stopped, if that can be avoided. Any
interruption of a movement presupposes a special effort of the will
which absorbs energy, and after the interruption a new start must be
made of which the same is true. On the other hand, if chains of
movements become habitual, the psychophysical effort will be reduced
to the minimum, inasmuch as each movement finds its natural end and is
not artificially interrupted by will, and at the same time each
movement itself becomes a stimulus for the next movement by its
accompanying sensations. The traditional method, for instance, demands
that a brick be lifted with one hand and a trowel with mortar by the
other hand. After that the lifting movement is interrupted, the brick
comes to rest in the hand of the mason until the mortar has been
spread on and the place prepared for the new brick. Then only begins a
new action with the brick. This method was fundamentally changed. The
laborers learned to swing the brick with one hand from the pack to
the wall and at the same time to distribute the mortar over the next
brick with the other hand. This whole complex movement is of course
more difficult and demands a somewhat longer period of learning, but
as soon as it is learned an extreme saving of psychophysical energy
and a correspondingly great economic gain is secured. The newly
trained masons are not even allowed to gather up with the trowel any
mortar which falls to the floor, because it was found that the loss of
mortar is economically less important than the waste of psychophysical
energy in bending down.
Whoever has once schooled his eye to observe the limitless waste of
human motions and psychophysical efforts in social life has really no
difficulty in perceiving all this at every step. This ability to
recognize possible savings of impulse may be brought to a certain
virtuosity. Gilbreth, one of the leaders of the new movement, seems to
be such a virtuoso. When he was in London, there was pointed out to
him in the Japanese British Exhibition a young girl who worked so
quickly that there at least he would find a rhythm of finger movement
which could not any further be improved. In an exhibition booth the
woman attached advertisement labels to boxes with phenomenal rapidity.
Gilbreth watched her for a little while and found that she was able
to manage 24 boxes in 40 seconds. Then he told the young girl that she
was doing it wrongly, and that she ought to try a new way which he
showed her. At the first attempt, she disposed of 24 boxes in 26
seconds and at the second trial in 20 seconds. She did not have to
make more effort for it, but simply had fewer movements to make. If
such economic gain can be secured with little exertion in the simplest
processes, it cannot be surprising that in the case of more complex
and more advanced technical work which involves highly skilled labor,
a careful psychophysical study of motions must bring far-reaching
economic improvements.
Yet the more important steps will have to be guided by special
experimental investigations, and here the psychological laboratory
must undertake the elaboration of the details. Only the systematic
experiment can determine what impulses can be released at the least
expense of energy and with the greatest exactitude of the motor
effect. Investigations on the psychophysics of movement and the
influences which lead toward making the movement too large or too
small have played an important rôle in the psychological laboratories
for several decades. It was recognized early that the mistakes which
are made in reproducing a movement may spring from two different
sources. They result partly from an erroneous perception or memory of
the movement carried out, and partly from the inability to realize the
movement intention. One series of investigations was accordingly
devoted to the studies of those sensations and perceptions by which we
become aware of the actual movement. Everything which accentuates
these sensations must lead to an overestimation of the motion, and the
outcome is that the movement is made too small. The concentration of
attention, therefore, has the effect of reducing the actual motion,
and the same influence must result from any resistance which is not
recognized as such and hence is not subtracted in the judgment of the
perceiver. Another series of researches was concerned with the inner
attitude which causes a certain external movement effect and which may
lead to an unintended amount of movement as soon as the weight to be
lifted is erroneously judged upon. Closely related studies, finally,
deal with a mistake which enters when the movement is reproduced from
memory after a certain time. The exactitude of a simple arm movement
seems to increase in the first ten seconds, then rapidly to decrease.
The emotional attitude, too, is of importance for the reproduction of
a movement. I trained myself in making definite extensor and flexor
movements of the arm until I was able to reproduce them under normal
conditions with great exactitude. In experiments extending over many
months, which were carried on through the changing emotional attitudes
of daily life, the exact measurement showed that both groups of
movements became too large in states of excitement and too small in
states of fatigue. But in a state of satisfaction and joy the extensor
movement became too large, the flexor movement too small, and _vice
versa_, in unpleasant emotional states the flexor movement was too
strong and the extensor movement too weak.[34]
We have a very careful investigation into the relations between
rapidity of movement and exactitude.[35] The subjects had to perform a
hand movement simultaneously with the beat of a metronome, the beats
of which varied between 20 and 200 in the minute. In general the
accuracy of the movement decreases as the rapidity increases, but the
descent is not uniform. Motions in the rhythm of 40 to the minute were
on the whole just as exact as those in the rhythm of 20, and, on the
other hand movements in the rhythm of 200 almost as accurate as those
of 140 to the minute. Thus we have a lower limit below which decrease
of rapidity does not increase the accuracy any further, and an upper
limit beyond which a further increase of rapidity brings no
additional deterioration. The mistakes of the unskilled left hand
increase still more rapidly than the number of movements. If the eyes
are closed, the rapid movements are usually too long and the slow ones
too short.
An investigation in the Harvard laboratory varied this problem in a
direction which brings it still nearer to technical conditions of
industry. Our central question was whether the greatest exactitude of
rhythmical movement is secured at the same rapidity for different
muscle groups.[36] We studied especially rhythmical movements of hand,
foot, arm, and head, and studied them, moreover, under various
conditions of resistance. The result from 340,000 measured movements
was the demonstration that every muscle group has its own optimum of
rapidity for the greatest possible accuracy and that the complexity of
the movement and the resistance which it finds has most significant
influence on the exactitude of the rhythmical achievement. If we
abstract at first from the fluctuations around the average value of a
particular group of movements and consider only this average itself in
its relation to the starting movement which it is meant to imitate, we
find characteristic tendencies toward enlargement or reduction
dependent upon the rapidity. The right foot, for instance, remained
nearest to the original movement at a rapidity of 80 motions in the
minute, while the head did the same at about 20. For a hand movement
of 14 centimeters, the most favorable rapidity was 120 repetitions in
the minute, while for a hand movement of 1 centimeter the average
remained nearest to the standard at about 40 repetitions. The mean
variation from time average is the smallest for the left foot at 20 to
30 movements, for the right at 160 to 180, for the head at 40, for the
larger hand movement at 180, and so on. Investigations of this kind
have so far not affected industrial life in the least, but it seems
hardly doubtful that a systematic study of the movements necessary for
economic work will have to pass through such strictly experimental
phases. The essential point, however, will be for the managers of the
industrial concerns and the psychological laboratory workers really to
come nearer to each other from the start and undertake the work in
common, not in the sense that the laboratory is to emigrate to the
factory, but in the better sense that definite questions which grow
out of the industrial life be submitted to the scientific
investigation of the psychologists.
XVI
EXPERIMENTS ON THE PROBLEM OF MONOTONY