Families are undergoing dramatic changes in our society. Our tradi- tional views are being challenged by new family arrangements. These new family arrangements are forcing redefinitions of what consti- tutes a family and raising significant issues regarding the potential developmental consequences for children in these families, if such exist. Moreover, the ramifications of redefined families and their bear- ing on children's development extend into the legal, political, and societal arenas. This book focuses on the relationships between di- verse family arrangements and children's development, as well as on legal and social implications. Our interest in this area emanates from our experience in directing the Fullerton Longitudinal Study. In the course of this investigation, we observed families undergoing transformation, most commonly in maternal employment and marital status. Our initial research on the role of maternal employment in children's development provided the scientific foundation for our interest. Just as we feel that maternal employment and dual-earner families should be comprehensively re- searched regarding their relationships to children's development, we also believe that other contemporary family arrangements should receive extensive attention in the developmental literature. Hence, the idea for this book emerged.