The facts derived from the study of the twelve exceptional persons herein described, and from the study of others like them, and the principles deduced from these facts, are of that order of importance for social science which Galton ascribed to them. Nevertheless, to hear of the tremendous differences between the dullest and the most intelligent individual, between the average man and the person who falls more than +10 PE away from him in mental ability, is extremely tedious to the typical American listener. This is only too well known to one who has long tried to interest foundations and moneyed persons in the education of gifted children. There is an apparent preference among donors for studying the needs and supporting the welfare of the weak, the vicious, and the incompetent, and a negative disregard of the highly intelligent, leaving them to "shift for themselves." Perhaps a wider dissemination of facts such as have been adduced in the studies of Professor Lewis M. Terman and other educators, and in this study, may eventually bring about a more constructive point of view, one more conducive to a recognition of national welfare involved in educational plans for the unusual student. It is desirable in this introduction to make known some of the etiquette and ethics involved in the scientific study of very gifted children. This is a new area in the field of human relationships and the investigator who works within it comes rather frequently upon certain questions of good manners which do not arise in any other field of psychological research. For instance, persons who test above 180 IQ (S-B) are almost sure to read and recognize in books and articles whatever has been written about them, no matter how anonymously they may have been described. This is true of them even as children. When the book _Gifted Children_ was published, in 1926, Child A, who is described therein as well as in these pages, was thirteen years old. He read the book within two weeks of publication; for, as he said in mentioning the matter to the author, "I go every week to the Public Library and look first at the shelf of new books." The problem always in the foreground is how to present the whole truth about such matters as family history, social-economic status, and character, without invading the privacy of those described and without identifying them to the general public or to curious persons. Those who test above 180 IQ (S-B) are characterized by a strong desire for personal privacy. They seldom volunteer information about themselves. They do not like to have attention called to their families and homes. They are reluctant to impart information concerning their plans, hopes, convictions, and so forth. The question arises, then, how to avoid presumption; for it is by no means easy for a young person politely to evade an older person who can lay claim to having known one "all one's life."