On the whole, then, all these studies point in a consistent direction; those who are destined to achieve distinction and success begin to do so at an early age. Whether measured by achievement in academic courses, honors in professional and technical courses, salary earned after graduation, or inclusion among lists and directories of eminent men, success in later life is suggested by success in the early work of the school curriculum. In spite of frequent comments to the contrary, the school curriculum would seem to constitute a useful test in prognosticating at least the most probable quality of the individual's later work. But our original three questions are at present answered with very unequal reliability. With respect to the relation between early success or failure in elementary school subjects and success or failure in handling more advanced subject matter, the evidence is clear and definite. On the question as to the permanence of interests and the relation between interest and ability, the evidence is far from adequate for vocational purposes. While the conclusion suggested is positive in Thorndike's study, the investigator recognizes that the results require confirmation or refutation at the hands of more reliable and verifiable information. It has appeared fairly certain that interest, as reflected in choice of college subjects, bears no relation to ability to undertake the work of at least two definite branches of professional training. On the third question, concerning the relation between general or particular academic aptitude or inclination and general or particular proficiency in later domestic, industrial, commercial, professional or civic activities, the data, although consistent, are far from complete. Here, then, as in so many other aspects of vocational psychology, we find an inviting field of research and an abundance of interesting problems. FOOTNOTES: [13] _Educational Review_, September, 1914. CHAPTER IX THE DETERMINANTS OF VOCATIONAL APTITUDE Without attempting to distinguish between the different detailed occupations, either on the basis of materials dealt with, the social or individual purposes realized, or the special qualifications demanded, we can still divide vocations broadly into five general types, depending on the degree to which they are likely to call for complete and normal psychological equipment. Such a classification is of little service in the concrete guidance of individuals, since the general types include work of the most diverse sorts; but it may be useful in suggesting the various types of qualities that are of vital importance in determining aptitude for any work at all, and may in this way aid in outlining the work of further investigation.