_II. Are the school subjects in which one is most interested in any way an indication of the interests and values of later life? What, in general, are the facts concerning the permanence of interests and the relation between interest and ability?_ These questions are of immediate interest to parents, teachers and vocational counsellors.
Here again we must turn to the work of Thorndike for almost the only available information, and even this is only preliminary and tentative, the results being subject to various sources of error. This investigator studied the interests and abilities in mathematics, history, literature, science, music, drawing and manual work. The original records are the judgments of one hundred individuals concerning the order of their own interests and abilities in these subjects at each of three periods in their school career, elementary school, high school and college. These various judgments having been made as conscientiously as possible, correlations were determined between interests at different times, interests and abilities, etc.
Individual relative interests at different times, according to these records, do not vary according to mere caprice. "A correlation of .60 or .70 seems to be approximately the true degree of resemblance between the relative degree of an interest in a child of from ten to fourteen and the same person at twenty-one." The resemblance between ability in elementary years and ability in college is found to be .65. The correlation between interest in the last three years of elementary school and capacity in the college period is computed to be about .60. This would mean that the early interest would serve as a useful indicator of adult capacity. "The correlation between an individual's order of subjects for interest and his order for ability is one of the closest of any that are known (about .90)." "A person's relative interests are an extraordinarily accurate symptom of his relative capacities."
In concluding his report Thorndike writes, "Interests are shown to be [not only permanent but also] symptomatic, to a very great extent, of present and future capacity or ability. Either because one likes what he can do well, or because one gives zeal and effort to what he likes, or because interest and ability are both symptoms of some fundamental feature of the individual's original nature, or because of the combined action of all three of these factors, interest and ability are bound very close together. The bond is so close that either may be used as a symptom for the other almost as well as for itself. The importance of these facts for the whole field of practice with respect to early diagnosis, vocational guidance, the work of social secretaries, deans, advisers, and others who direct students' choices of schools, studies, and careers is obvious. They should be taken account of in such practice until they are verified or modified by data obtained by a better method; and such data should soon be collected. The better method is, of course, to get the measurements of relative interest and of relative ability, not from memory, but at the time, and not from individuals' reports alone, but by objective tests."