The more scientific management introduced changes by which the individual achievement often had to become rather complicated and difficult, the more it became necessary to study the skill and the endurance and the intelligence of the individual laborers in order to entrust these new difficult tasks only to the most appropriate men in the factories and mills. The problem of individual selection accordingly forced itself on the new efficiency engineers, and they naturally recognized that the really essential traits and dispositions were the mental ones. Yet this is very far from a real application of scientific psychology to the problem at hand. Wherever the question of the selection of the fit men after psychological principles is mentioned in the literature of this movement, the language becomes vague, and the same men, who use the newest scientific knowledge whenever physics or mathematics or physiology or chemistry are involved, make hardly any attempts to introduce the results of science when psychology is in question. The dearest insight into the general situation may be found in the most recent books by Emerson.
Apprenticeship is rigorously limited.
But all this points only to the existence of the problem, and in reality gives not even a hint for its solution. The theorists of scientific management seem to think that the most subtle methods are indispensable for physical measurements, but for psychological inquiry nothing but a kind of intuition is necessary. They had to place a row of small polished steel balls on the back of the left hand and while they were rolled over and over in the crease between two of the fingers placed together, they were minutely examined in a strong light and the defective balls were picked out with the aid of a magnet held in the right hand. The work required the closest attention and concentration. The girls were working ten and a half hours a day.