ned on the level of helpless
psychological dilettantism. It stands in striking contrast with the
scientific seriousness with which the economic questions are taken up
in the field of vocational guidance and the physical questions in the
field of scientific management. It is, therefore, evidently the duty
of the experimental psychologists themselves to examine the ground
from the point of view of the psychological laboratory.

VII

THE METHODS OF EXPERIMENTAL PSYCHOLOGY

We now see clearly the psychotechnical problem. We have to analyze
definite economic tasks with reference to the mental qualities which
are necessary or desirable for them, and we have to find methods by
which these mental qualities can be tested. We must, indeed, insist on
it that the interests of commerce and industry can be helped only when
both sides, the vocational demands and the personal function, are
examined with equal scientific thoroughness. One aspect alone is
unsatisfactory. It would of course be possible to confine the
examination to the individual mental traits, and then theoretically to
determine for which economic tasks the presence of these qualities
would be useful and for which tasks their absence or their deficiency
would be fatal. Common sense may be sufficient to lead us a few steps
in that direction. For instance, if we find by psychological
examination that an individual is color-blind for red and green
sensations, we may at once conclude, without any real psychological
analysis of the vocations, that he would be unfit for the railroad
service or the naval service, in which red and green signals are of
importance. We may also decide at once that such a boy would be
useless for all artistic work in which the nuances of colors are of
consequence, or as a laborer in certain departments of a dyeing
establishment, and that such a color-blind girl would not do at a
dressmaker's or in a millinery store. But if we come to the question
whether such a color-blind individual may enter into the business of
gardening, in spite of the inability to distinguish the strawberries
in the bed or the red flowers among the green leaves, the first
necessity, after all, would be to find out how far the particular
demands of this vocation make the ability to discriminate color a
prerequisite, and how far psychical substitutions such as a
recognition of the forms and of differences in the light intensity,
may be sufficient for the practical ta