psychology adjusted experiments to the particular needs of the
courtroom. Investigations were carried on to determine, the fidelity
of testimony or to find methods for the detection of hidden thoughts
and so on. Efforts toward the application of psychology have
accordingly grown up in the fields of pedagogy, medicine, and
jurisprudence, but as these studies naturally do not remain
independent of one another, they all together form the one unified
science of applied psychology.[2]

As soon as the independence of this new science was felt, it was
natural that new demands and new problems should continue to originate
within its own limits. There must be applied psychology wherever the
investigation of mental life can be made serviceable to the tasks of
civilization. Criminal law, education, medicine, certainly do not
constitute the totality of civilized life. It is therefore the duty of
the practical psychologist systematically to examine how far other
purposes of modern society can be advanced by the new methods of
experimental psychology. There is, for instance, already, far-reaching
agreement that the problems of artistic creation, of scientific
observation, of social reform, and many similar endeavors must be
acknowledged as organic parts of applied psychology. Only one group of
purposes is so far surprisingly neglected in the realm of the
psychological laboratory: the purposes of the economic life, the
purposes of commerce and industry, of business and the market in the
widest sense of the word. The question how far applied psychology can
be extended in this direction is the topic of the following
discussions.