Measure Your Mind: The Mentimeter and How to Use It

by Marion Rex Trabue; Frank Parker Stockbridge

While the determination of individual skill in the performance of a given operation is not, strictly speaking, a test of intelligence or of mental capacity, it has been established that the most accurate and speedy method of discovering the precise degree of skill possessed by any artisan is closely analogous to the scientific method of mental measurement. It has been found, moreover, that there is quite a close relation between an individual workman’s skill at his trade and the degree of mental capacity disclosed by the Mentimeter or similar scientific tests; the more intelligent the worker, the greater his skill if he has any natural aptitude for his trade.

Many persons view with skepticism the idea that a workman’s degree of skill at his trade can be determined by tests that require but a few minutes. A month, they argue, is little enough for an expert foreman to classify justly the men under him, after observing their skill with his own eyes. When it is proposed that those who apply the tests for any trade need not themselves be skilled in it and may, in fact, know nothing about it, it is no wonder that they doubt the practicality of a method so foreign to previous conceptions and practice.

Psychologists have long realized that the same methods by which mental qualities, abilities, and capacities are determined, analyzed, and measured, could be applied to the measurement of manual dexterity or the combination of manual dexterity, judgment, perception, adaptability, and patience that, taken together, make the skilled workman. For, as the reader who has perused this book thus far will long since have recognized, there is included in the foregoing list of qualities a predominance of those which come quite definitely under the classification of mental abilities or capacities. As has been previously pointed out, it is impossible to separate mental and physical powers, and psychologists do not regard the mind as a separate entity, but merely as a convenient term for the definition of certain of the higher physical powers and their manifestations. And just as a certain type of nervous (physical) organism manifests itself in the development of abilities which we are accustomed to term “intellectual” or “mental,” so the abilities which we call “physical” or “manual” are merely other manifestations of a different type of nervous organism.

The principal distinction, scientifically, between a trade test and an intelligence test, is in the purpose to be served by the test. In the intelligence test the aim is to ascertain the subject’s general capacity; in the trade test, to discover his present ability or degree of skill in some special direction. Capacity, as has been previously pointed out, is only to be measured in terms of demonstrable ability, so that in the application of trade tests, although limited in their scope to a single class or kind of ability, there is also obtainable as a by-product a partial measure of the subject’s mental capacity.

While trade tests devised by psychologists had been demonstrated, in a number of industries, to be superior to any other method, both in picking the most skilful workers from among all applicants for positions, and in transferring workers from one department to another in large industries, it was in the classification and placement of the personnel of the Army during the war that the first really large-scale demonstration of the precision and effectiveness of scientifically devised trade tests was made. While one group of psychologists, working under the direction of the Surgeon-General’s Office, was engaged in classifying the Army personnel by means of intelligence tests the Personnel Branch of the Operations Division of the General Staff, organized and officered by trained psychologists, was undertaking the task of determining the special technical and vocational ability of the millions of men drawn into the Army through the medium of the selective draft.

This personnel organization had a multiplex duty to perform. First, it had to ascertain with precision what particular kinds of work had to be done in the preparation of an army for battle and in its transport and maintenance. This involved not only finding out just what needed to be done but translating this need into terms of trades and occupations.

For example, the Army might report that it needed a number of men capable of making all sorts of repairs to electric generators and motors. The Personnel Division proceeded to analyze the special qualifications required of electricians to enable them to meet this demand. These were listed, along with the qualifications required for every other army occupation, in a thick book entitled Trade Specifications Index. There were 239 pages in this book and in it were set forth in specific detail the exact qualifications needed by 565 different kinds of trade and technical experts. Chauffeurs, for instance, were classed as auto drivers, auto drivers with pigeon experience, motorcycle drivers with pigeon experience, plain motorcyclists, heavy auto-truck drivers, motor truck drivers, and plain chauffeurs. There were sixteen different classes of electricians, each of which required a man with special experience and knowledge. Nine different kinds of chemists were used in the Army.

It was a big job, in the first place, to determine exactly how men should be classified. After the classification had been decided upon, it then became necessary to devise simple, rapid, and accurate methods of placing every enlisted man in the Army in his proper classification, and then of so indexing three or four millions of men that any particular demand could be met. For example, one camp might ask for three farriers, nine sanitary engineers, two car carpenters, six boilermakers, and a pipe fitter. It was necessary that some system be perfected to permit of the filling of this order instantly by taking the men qualified to perform these duties out of the camps where they were undergoing military training.

The whole system had as its basis a card for each soldier, on which, by a simple system of marginal numbers, punch holes, and coloured index tags the record of each man’s precise ability was kept. Every man, as he was inducted into the service, was required first to make a preliminary, rough classification of himself—that is to say, he recorded himself as a tailor, a blacksmith, or a milk wagon driver. But the Trade Specifications Index was as precise in its detail as a dictionary. It was, in fact, a collection of definitions of what was meant by occupational titles which had vague or various meanings in different parts of the country. Thus, a man might have classified himself as a tailor who, if called upon to make a uniform, would have been unable to do so. Tailoring had to be subdivided, from simple pressing and repairing up to expert fitting. One might be a good coat maker while another had never worked on anything but trousers.

So there was devised a system of trade and occupational tests to which every man claiming skill at a trade was subjected, and which determined, as nearly as it is humanly possible to do, exactly the degree and kind of vocational skill possessed by every man in the Army.