This book investigates the development of object permanence in infants and its implications for cognitive growth. Wellman, a developmental psychologist, examines the foundational research and theoretical frameworks surrounding how infants learn that objects continue to exist even when they cannot be seen, heard, or touched. The work synthesizes empirical studies and proposes a nuanced understanding of this critical cognitive milestone, exploring its relationship to other aspects of infant cognition and behavior.

The book is recognized as a significant contribution to the field of developmental psychology, particularly in its detailed exploration of infant cognition. It is often cited for its comprehensive review of early research and its theoretical insights into the emergence of object permanence. The work is considered a valuable resource for researchers and students studying cognitive development in infancy.