In an age in which the word psychology is so widely used by so many different people in such a variety of ways, one approaches the discussion of the relation between psychology and pediatrics with some fear and trembling. This is in part due to a feeling that, when the discussion is completed, psychology may seem to be a much more prosaic endeavor than most people believe, and to hold out somewhat less hope of meeting all our unsolved problems of human relations, at least within the next generation. To many, psychology is a word to be glibly rolled off the tongue, whenever an inexplicable fact of human action occurs or a quick and easy explanation is sought. To those who are earnestly engaged in the business of trying to formulate valid principles of human behavior and to contribute to our understanding of human nature, psychology is a term which,