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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.



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

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

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

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

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

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

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

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

I proceeded in the following way. To make use of a large number of
subjects accustomed to intelligent self-observation, I made the first
series of experiments with the regular students in my psychology
lecture course in Harvard University. Last winter I had more than four
hundred men students in psychology who all took part in that

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