ly
be increased.

The chief danger, moreover, lies in the fact that those who are not
accustomed to psychological laboratory research are easily misled.
They fancy that such an experiment can be carried out in a mere
mechanical way without careful study of all the conditions and
accompanying circumstances. Thereby a certain crudeness of procedure
may enter which is not at all suggested by the test method itself. The
psychological layman too seldom recognizes how many other psychical
functions may play a role in the result of the experiment beside the
one which is interesting him at that moment. The well-schooled
laboratory worker almost automatically gives consideration to all such
secondary circumstances. While his experiments may refer to the
process of memory, he will yet at the same time carefully consider the
particular situation as to the emotional setting of the subject, as to
his attention, as to his preceding experience, as to his intelligence,
as to his physiological condition, and many other factors which may
have indirect influence even on the simplest memory test. Hence the
real performance of the experiments ought to be undertaken only by
those who are thoroughly familiar and well trained in psychological
research. And they alone, moreover, can decide what particular form
such an experiment ought to take in a given practical situation. It
must be left to them, for instance, to judge in which cases the mental
function of economic importance ought to be tested after being
resolved into its components and in which it ought to be examined in
its characteristic unity.

XI

CONTRIBUTIONS FROM MEN OF AFFAIRS

While the psychologists have to perform the actual labor, the
representatives of practical life are much better able to indicate the
points at which the psychological levers ought to be applied. In the
past year I have sought contact with several hundred large concerns in
America which belong to many different industrial realms. My time did
not allow me personal observation in so many cases, but everywhere I
begged for information from the leading men. I asked in individual
letters for the particular psychological qualities which from the
standpoint of the management seemed essential for the various kinds of
labor in their establishments. I always inquired to what extent
consideration was given to such psychological points of view at the
appointment of applicants, and asked for material concern