Practical Psychology

PRACTICAL PSYCHOLOGY Human Nature in Everyday Li e BY EDWARD STEVENS ROBIN QN ASSOCIATE PROFESSOR OF PSYCHOLOGY THE UNIVERSITY OF CHICAGO THE MACMILLAN COMPANY 1926 All rights reserved PRINTED JIf TUB UNITED STATES OF AMEIUCA COPYHICSHT, l 2t, TTIR MACMILLAN COMPANY. Sot up ami clerlrotyp-U. Publihliod August, 1920. Press of J. J. Little Ives Company New York TO MY COLLEAGUE, F. R. R. PREFACE The great majority of students who spend one quarter or one semester in a general course in psychology do no further work in this field. And many of them have no reason to go forward to expertness in such related fields of science as might revive the accomplishments of their brief experience in psychology. The short course in psychology can be made profitable only if the peculiar needs of such a course be squarely faced. Under these circumstances there should be a strong effort to integrate psychology with the issues of the work-a-day world. This does not require the teaching of the technical applications of psychology. It does, however, require the teaching of a practical psy chology. Such a practical psychology is one in which scientific principles are given more emphasis than technical devices. But, more than this, it is a psychology in which these principles are selected and treated in such a way as to bring out their intimate relations to the personal and social life of the student. The present book is an attempt at such a psychology. The educational background presupposed by this text is no greater than is likely to be possessed by a student in the latter part of the high school course. I believe that, with the use of such supplementary readings as are suggested at the end of each chapter, the book will also be fitted for college classes. It should be especially appropriate for students who are going almost immediately into the study of education, business, law, and other professional subjects. In trying to administer to such needs as these I hope that viii PREFACE I have done something which the general reader will find interesting. In the writing of the book I have had much friendly assistance. From the inception of the project Florence Richardson Robinson has helped me on every type of problem that authorship involves. Professor Leon C. Marshall was one of those who first encouraged the plan of writing such a book as this. His criticisms of the manu script have been invaluable. All, or nearly all, of the chapters have been read and commented upon by Professor Harvey Carr, Professor Leverett S. Lyon, Professor Francis M. Maxfield, Mr. Henry Reed Burch, and Mr. John A. Powell. Each from his own point of view has made many important suggestions. Authors and publishers have been kind in permitting the use of illustrations and quotations. I have given specific credit for each of these favors at that place in the text where the material concerned is used. E. S. R. Chicago July, 1926. CONTENTS PART I PREPARATION FOR PSYCHOLOGY CHAPTER I THE SCIENCE OP PSYCHOLOGY PAGE A. The Subject-Matter of Psychology 3 B. The Methods of Psychology 7 C. The Uses of Psychology 10 Summary of the Chapter 14 CHAPTER II HUMAN NATURE AND THE HUMAN BODY A. How the Nervous System, the Sense-Organs, the Muscles, and the Glands Work Together 17 B. Special Organs Involved in Behavior and Mental Life ... 21 Summary of the Chapter 38 PART II HABITS AND THEIR ACQUISITION CHAPTER III REFLEXES AND HABITS A.Characteristics of Reflexes and Habits 46 B. Types of Habits 51 Summary of the Chapter, 64 x CONTENTS CHAPTER IV THE FORMATION OF HABITS PAGE A. The Basis of New Habits 68 B. How Experience Modifies Behavior 70 C. Conditions under Which We Learn 75 Summary of the Chapter 86 CHAPTER V THE FIXATION AND ELIMINATION OF HABITS A. The Rate and Limit of Learning 90 B. The Curve of Learning 110 C. Features of Established Habits 119 D. The Elimination of Habits 121 Summary of the Chapter 127 CHAPTER VI THE OPERATION OF HABITS A...