In my efforts to learn something about the nature of the child, as a member of child-study groups, and in my own studies, I have found a large mass of material--accumulated by investigators into the psychology and the biology of childhood--which could be of great practical use to all concerned with the bringing up of children. In this little book I have tried to present some of this material in a form that will make it available for those who lack the time, or the special training or the opportunity to work it out for themselves. It has been my chief aim to show that a proper understanding of and sympathy with the various stages through which the child normally passes will do much toward making not only the child happier, but the task of the parents pleasanter. I am convinced that our failure to understand the workings of the child's mind is responsible for much of the friction between parents and children. We cannot expect the children, with their limited experience and their undeveloped intellect, to understand us; if we are to have harmony, intimacy and cooperation, these must come through the parents' successful efforts at understanding the children. In speaking of the child always in the masculine, I have followed the custom of the specialists. It is of course to be understood that "he" sometimes means "she" and usually "he or she." It has been impossible to refer at every point to the source of the material used. One unconsciously absorbs many ideas which one is unable later to trace to their sources; in addition to this, the material I have here presented has been worked over so that it is impossible in most cases to ascribe a particular idea to a particular person. I wish, however, to acknowledge my indebtedness to all who have patiently labored in this field, and especially to those Masters of Child Study, G. Stanley Hall, John Dewey, Earl Barnes, Edwin A. Kirkpatrick and Edward L. Thorndike. I owe much to my opportunity to work in the Federation for Child Study. These groups of mothers and teachers have done a great deal, under the guidance and inspiration of Professor Felix Adler, to develop a spirit of co-operation in the attack upon the practical problems of child-training in the home. I am very grateful to Mrs. Hilda M. Schwartz, of Minneapolis, for her assistance in revising the manuscript and in securing the illustrations. The assistance of my husband has been invaluable. In his suggestions and criticisms he has given me the benefit of his experience as biologist and educator. SIDONIE MATZNER GRUENBERG. New York May, 1913. A FOREWORD