'The biological birth of the human infant and the psychological birth of the individual are not coincident in time. The former is a dramatic, observable, and well-circumscribed event; the latter a slowly unfolding intra psychic process.'Thus begins this highly acclaimed book in which Margaret S. Mahler and her collaborators break new ground in developmental psychology and present the first complete theoretical statement of Dr. Mahler's observations on the normal separation-individuation process.Separation and individuation are presented in this major work as two complementary developments. Separation is described as the child's emergence from a symbiotic fusion with the mother, while individuation consists of those achievements making the child's assumption of his own individual characteristics. Each of the sub-phases of separation-individuation is described in detail, supported by a wealth of clinical observations which trace the tasks confronting the infant and his mother as he progresses towards achieving his own individuality.A number of chapters are devoted to following five children epigenetically through their sub phase development. A separate section describes the authors' methodology, the importance of the research setting, and the effects of changes in the setting. The extensive appendices by Fred Pine discuss the uniqueness of the data-gathering techniques used by the author. In addition, a useful glossary of concepts defines the new terms that Dr. Mahler has introduced.This book represents an important breakthrough in understanding the human infant and makes a unique contribution to the science of human behavior.