Range of Human Capacities

In the following pages I have attempted to summarize our knowledge regarding individual differences, more specifically those aspects of it which bear on the limits and range of human capacities, and to draw such inferences from the data available as the facts seem to warrant.Both the facts and the generalization may afford the reader some surprise, the former because many of the data collected will be treated in an unfamiliar way, the latter because the conclusions are for the most part at variance with current opinions on the subject. The reader will at all times be able to verify the facts by referring to the original sources from which they were taken. As regards the conclusions, the only suggestion I can make is that in evaluating them he lay aside, for the time being, any previous opinion he may have held, and seek to come to some conclusion himself in the light of the facts presented. I believe this effort will be amply repaid because the implications of some of the conclusions have, it seems to me, rather important bearings on a number of social questions with which thinkers all over the world are at present attempting to grapple. Outstanding among these, perhaps, are the status of democracy, the problem of technocracy in relation to human efficiency, and now, in a larger sense, the suggested attempts at social reorganization on the basis of abilities and needs as contrasted to geographical distributions and caste systems. I have not, myself, attempted to answer any of these questions, but I believe the material contained in this book should enable those who are concerned with them to approach the subject in a more scientific and, I might add, also in a more hopeful way.