This book investigates the psychology of family relationships, including parent-child relations, sibling relations, maternal-fetal and marital relations. The influence of prenatal mother-child attachment on intrauterine fetal movements is examined, as well as mother-infant interaction, which was studied by looking at Nicaraguan and Italian mothers and how they engage in social play, object play, and what their overall verbal behaviors were towards their infants. In addition, rather than the usual focus on dietary and physical activity aspects of child weight management, certain family relationships are highlighted, which might either enhance or hinder coping with child weight management. Sensitivity is reflected in many different ways in maternal behavior. This book examines maternal sensitivity and its association with child-directed speech (CDS). In addition, the changes in how parents interact with their toddler-aged children are described as they move from dyadic to family contexts. Several models depicting the role of adolescent ratings of self-esteem anxiety and/or depression, particularly in late adolescence, are also examined. This book addresses the relationships among siblings and how individual differences in emotionality at the behavioral level of analysis correlates at the cognitive and physiological levels. In addition, childhood sibling relationship quality is examined in terms of how it is correlated with achievement motivation and college GPA in young adulthood. The association between the child’s personal characteristic with their relationships in family and social environments are also described. Furthermore, psychological processes affecting post-divorce paternal functioning are explored. In addition, a psycho-educational program for advancing children’s coping skills and helping them to cope with marital conflict is also examined.