“4. The test result is little influenced by the subject’s educational advantages. In this it differs greatly from offhand judgment, which so easily mistakes the results of schooling for real intelligence. The test method probes beneath the veneer of education and gives an index of raw ‘brain power.’ For example, a young woman who had been stolen in early childhood by gypsies and had spent her life with them was given the Binet-Simon intelligence test. She had never attended school a day in her life and had only learned to read by bribing a little school girl to teach her the alphabet; yet she made a higher score than the average found for two hundred high school pupils who were given the same test. “No wonder,” Professor Terman concludes, “mentality tests have acquired such a wide vogue in the ten years since Binet gave to the world the first successful intelligence scale. In that time they have demonstrated their usefulness in the study of the feeble-minded, in the grading of school children, in determining the mental responsibility of offenders, and in the selection of employees. Their largest and most useful applications have been in the mental classification of men in the United States Army.” CHAPTER II THE APPLICATIONS OF PSYCHOLOGICAL TESTS The intelligent reader has by this time begun to see for himself some of the possibilities opened up by the use of scientific mental tests, and to perceive their applicability in a wide diversity of fields. In later chapters specific examples of such applications are given in detail, and suggestions offered for still other uses of the tests which are contained in this book. The usefulness of all mental tests, whether those which are offered in this volume under the general title of “The Mentimeter,” or others that may be set up with equal scientific precision, depends upon, or at least is greatly enhanced by, the most complete understanding of the underlying principles on the part of the person who undertakes to apply them. The purpose of this and the next three succeeding chapters is to make these principles so plain that by the time the reader has reached the tests themselves he will have a perfectly clear understanding, not only of _what_ the Mentimeter tests are but of _why_ they have been put into the form in which he finds them, and of _how_ their use will enable him to gauge human intelligence and capacity with a greater degree of accuracy than he has found possible by other means. If, perchance, psychologists find in this volume much that is to them elementary, it should be kept in mind that it is only through the widest possible spread of sound understanding of psychological principles that the wider application of them in the ordinary walks of life can be brought about. That, the authors take it, is the great end toward which scientific psychologists are aiming, and that is the aim of this book.