In this sixth edition of Child Development, which first appeared in 1942, attempts have been made to make it a better teaching tool for instructor`s and a better, more interesting learning tool for students by following changes and additions. First, because of favorable reactions to the boxes used to highlight important facts in the previous editions, more boxes are used in this edition. Second, at the end of each chapter a section has been added to stress the important hazards in the area of development covered in the chapter. Third, the bibliographies, given at the end of each chapter, have been updated by omitting many of the older studies to provide space for the newer ones in the same area. Fourth, fewer graphs from research studies have been used than in the earlier editions of this book. Fifth, while all revisions update old material, this revision has added material from research areas that are somewhat off the beaten track and have not yet appeared in many of the textbooks in child development. Sixth, because of the important role theories about different areas of development have played in spurring research in those areas, a brief discussion of some of the most influential theories has been added. Seventh, to eliminate the distraction to readers of constant reference in the text to sources from which the material has been taken, relatively few references are given throughout the chapters.