Central in interest and promise stands the psychological test. In so far as psychology has laid bare the fundamental qualities upon which achievement depends, its application has developed a series of tests to determine how the individual compares with the others or with the average in respect to this, that, and the other constituent quality. Professor Hollingworth presents the results of such analysis, both in relation to the variety of human traits and in the grading of individuals by reference to the measure of the quality which each possesses. The enumeration is at best provisional, but in its totality cannot go far wrong in establishing the measure of a man. It includes the qualities which can hardly be determined otherwise than by an impressionistic judgment, as well as those appraised by actual achievement under test. There results a mental scale of general ability, adequate to gauge normality and to suggest practical standards of superiority or deficiency.
The question at once arises: how far are the qualities desirable for this or that vocation of a general order, and how far are they specific in their demands. In this respect vocations differ widely. The musical vocation exemplifies a specialized profession depending upon a proficiency that is largely a dower of heredity; yet within this field the psychological test has proved its efficiency by determining the still more specialized facilities that jointly compose the psychology of the musician. In further pursuit of insight the psychological laboratory has undertaken to analyze the qualities needed for the several specialties of modern vocational life, by setting up "test" counterparts of practical occupations, by reducing them to their underlying facilities, by testing the correlation of quality and achievement, and by combining the clues or verdicts of several methods. Conclusions depend for their value upon logical caution and the technical methods which have been developed to meet these applications. All this is as yet but a program or a limited beginning in its execution; but it is a program well founded in principle and already in part available in practice.
A group of collateral interests supports the enterprise and yields valuable results. The interest in unusual men has led to the psychograph or psychological analysis of the qualities of great men, as an individual study. Men fall into types, by temperament and achievement, by heredity and career. The type makes definite the larger contours of human differences and reveals their specific combination; the charm of biography is psychological as well as historical. The vital import of heredity--practically expressed in the eugenic movement--finds recognition in the study of correlation of traits in those near of kin. Evolution leads to prediction; early taste, talent, achievement, precocity foreshadow ultimate capacity; we learn how far the child is father to the man, how far we may see the future in the early expressions and with what limitations the environment molds character. The most valued because most authentic type of biography is autobiography. Self-analysis is intimate if unreliable, but by this token worthy of study. Professor Hollingworth's contribution to the measure of reliance to be placed upon one's judgment of self in comparison with one's judgment of others and others' judgment of him forms an interesting original study--one of many--incorporated in these chapters.