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. Of distinctive status are the tests of ability presented by life itself and by the conventional institutions which compose the social environment. The processes of education, the rate of advance, the comparative readiness with which one or another discipline is absorbed and mastered: these are at once preparations for life and accredited tests of ability. For these reasons such "school" qualities are subjected to a special study; and fairly conclusive results indicate to what measure they must be supplemented, if not superseded, by the designed psychological test, to meet the conditions of actual selection and employment of men. At this point the several methods converge; for the vocations have a vital interest in the school, as has the school in vocational application of its discipline and training. The actual comparison of results, especially by the method of correlation, has already established the degree of relation--and eventually of cooperation--to be expected of the two. In all these ways has painstaking method supplemented and replaced impressionism, haphazard opinion been supported or overturned by accumulation of fact, and the scientific approach to the study of vocational fitness become firmly established. The road from theory to practice, if it is to be well built and enduring, must be laid on careful foundation. To such an end this volume is a worthy contribution.