To the scientific reader we would say that the data here presented are, we believe, accurate to a high degree. It is true that we have made rather dogmatic statements and have drawn conclusions that do not seem scientifically warranted from the data. We have done this because it seems necessary to make these statements and conclusions for the benefit of the lay reader, and it was impossible to present in this book all of the data that would substantiate them. We have, as a matter of fact, drawn upon the material which is soon to be presented in a larger book. The reference to Mendelism is an illustration of what we mean. It is, as it is given here, meager and inadequate, and the assumption that the given law applies to human heredity is an assumption so far as the data presented are concerned. We would ask that the scientist reserve judgment and wait for the larger book for the proof of these statements and for an adequate discussion of Mendelism in relation to the problem. The necessary expense for this study, as well as for all of the work of the Research Laboratory, has been met by voluntary contributions from philanthropic men and women, who believe that here is an opportunity to benefit humanity, such as is hardly equaled elsewhere. We take this means of expressing to them our deep appreciation of their sympathy and generosity. I wish also to make special mention of the indefatigable industry, wisdom, tact, and judgment of our field workers who have gathered these facts and whose results, although continually checked up, have stood every test put upon them as to their accuracy and value. The work on this particular family has been done by Elizabeth S. Kite, to whom I am also indebted for practically all of Chapter IV. I am also greatly indebted to my assistants in the laboratory, for help in preparing the charts, keeping the records, and correcting manuscript and proof. To Superintendent Edward R. Johnstone, whose wisdom and foresight led to the establishment of this Department of Research, whose help, sympathy, and encouragement have been constant throughout the work of preparing this study, the thanks and gratitude of the entire group of readers who find in these facts any help toward the solution of the problems that they are facing, are due. HENRY H. GODDARD. VINELAND, N.J., SEPTEMBER, 1912. CONTENTS PAGE PREFACE vii I. THE STORY OF DEBORAH 1 II. THE DATA 13 THE CHARTS 33 III. WHAT IT MEANS 50 IV. FURTHER FACTS ABOUT THE KALLIKAK FAMILY 70