Early applied psychology between essentialism and pragmatism; the dynamics of theory, tools, and clients

The indebtedness of applied psychology to classical laboratory psychology is much greater than is usually assumed. It manifests itself both in the initial use of laboratory apparatus and diagnostic tools and in the conception of vocational fitness as a matter of the same elementary mental functions as those measured in the laboratory. In America this psychological essentialism soon gave way to a more pragmatic approach, aimed at prediction of success. As the history of the psychotechnical movement shows, this transition occurred on the European continent much later. The disparity is explained by differences in the primary audience of the pioneers of practice at both sides of the Atlantic. The development of occupational psychology is used as a case of transition in investigative style in general.