Introduction

This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book explores the theoretical and empirical issues involved in the early appearance of a behavior, its "disappearance" and its later "reappearance." The varied research attests to the existence of many such behaviors. There is considerable disagreement about the descriptive and theoretical status of the phenomena. Nevertheless, the authors agree that such facts demonstrate that the additive view of adult behavior is incorrect: Mental growth must be the result of dynamic restructuring processes. The study of developmental regressions has received sporadic attention during the past century. Science depends on noticing that things which seem identical are different, and conversely. In psychology, one cannot assume that apparently identical behaviors are due to identical mechanisms. The book attempts to interpret, explain, or explain away such developmental regressions in a variety of different areas.