Many people grow up with at least one sibling. These siblings are often ‘fellow travellers’ through adversity or significant life events; they can act as a source of support for some children while a source of conflict for others. For these reasons, siblings are a potentially powerful influence on development and this book is one of the first of its kind to provide an overview of cutting-edge psychological research on this important relationship. Why Siblings Matter is a cornerstone text on siblinghood. Integrating findings from a 10 year longitudinal study alongside wider research, it provides a lifespan perspective examining the impact of sibling relationships on children’s development and well-being. This text situates siblings in their historical, developmental and family context, considers the influence of siblings on children’s development and adjustment, and provides an introduction to new research on siblings in diverse contexts. The authors discuss sibling relationships in varied populations such as siblings with disabilities, siblings in different cultures and siblings in non-traditional families, while also considering the practical implications of research. Covering both classical studies and new results this book offers take-home messages for promoting positive sibling interactions. It will be invaluable reading for students and researchers in developmental psychology and family studies and professionals in education, health and social work.

The majority of Americans have siblings, who provide one another with warmth, support, and friendship, and also serve as a source of conflict, throughout the life course. Past research shows that sibling relationship quality influences mental health and self-concept. Over the past several decades, as more parents break up and re-partner, a substantial proportion of America's youth grow up with half-siblings or step-siblings. Limited research has examined how sibling relationship quality with half-siblings or step-siblings differs from those with full-siblings, however.Using Waves II and III of the National Longitudinal Study of Adolescent to Adult Health, drawing from the core sample (N = 8,402) and the residential sibling pairs sample (N = 1,753), this dissertation examines the following three questions : (1) Does residential sibling relationship quality in adolescence, measured as feelings of love, fights, and time spent together, vary across full-siblings, half-siblings, and step-siblings, controlling for variation by sibling type in family characteristics, such as mother-child relationship quality, father-child relationship quality, and family belonging? (2) Does sibling relationship quality in young adulthood, measured as visits, phone calls, help-seeking, fights, and emotional closeness, vary by sibling type, controlling for sibling relationship quality during adolescence? (3) Does the association between relationship quality with residential siblings in adolescence and mental health and self-concept in young adulthood differ across the three residential sibling types?The findings suggest that among residential siblings, with the same family characteristics, relationships with step-siblings are more distant than those with full-siblings or half-siblings, while relationships with half-siblings are similar to those with full-siblings, both in adolescence and young adulthood. Emotionally close relationships and fights with siblings in adolescence are associated with better self-esteem and fewer depressive symptoms in young adulthood, with variation by sibling type in ways that are more complex than predicted based on the "stepfamily as incomplete institution" perspective. Fights indicate closer, rather than more distant, sibling relationships. Overall, the findings contribute to the existing bodies of family, sibling, and mental health research, suggesting the merit to further investigating differences in the nature of full-siblings, half-siblings, and step-siblings and their implications for individual well-being across different life stages.

The most long-lasting and enduring relationship an individual can develop is with a sibling. Considering the closeness in age and early association of siblings, they can bond for a lifetime. Psychologists are beginning to appreciate the sibling link and its dynamic role in a child's social development. Beyond the mother-child dyad, sibling associations are now attributed with determining cognitive faculties, emotional balance, self-sufficiency, and peer interactions. Clarifying the complex processes of these relationships and the benefit of parental involvement, Avidan Milevsky provides a foundational text for a growing area of study. Deploying personal narrative, theoretical examinations, and empirical data, he unravels the intricacies of the sibling exchange and their function in overall family structures. He identifies the factors that make such bonds successful (or harmful) and the influence of parents in shaping these outcomes. He also evaluates the compensatory possibilities of the sibling bond when faced with the absence of a parent or friend. Variables such as age, birth order, gender, and family size are tremendous considerations, and parents hoping to enhance the sibling bond gain immensely from understanding these predictors. Milevsky shows practitioners how to educate parents and help them apply their knowledge in practice. He particularly supplies crucial perspective on "deidentification," or conscious differentiation, in which parents encourage different life paths to minimize sibling comparison and competition. A major tool for clinicians, social service providers, and educators, this book clarifies the next frontier in child development research.

Siblings serve an important role within each other's lives throughout the life course. The relationships between siblings do not develop in isolation; sibling relationships are governed by the rules and expectations of the family of origin. One of these characteristics is family distance regulation, which consists of two components: separateness and connectedness. The interplay between these two components may influence the quality of the sibling relationship as well as individual outcomes, such as stress and depression. This study utilized Actor Partner Interdependence Models to understand the associations between these variables within sixty four sibling pairs (thirty three female female dyads, thirty one female male dyads) during emerging adulthood, a transitional developmental period. Overall, it appears that family distance regulation is not associated with sibling relationship quality, save for within female male dyads. Brother's separateness was associated with lower sister's perceived warmth between siblings. Additionally, distinct patterns emerged between warmth and individual stress based on the gender make up of the dyad. Both sisters' warmth was associated with lower personal stress and higher sibling stress. This may indicate that during times of stress, sisters reach out to their other sister, signaling that the relationship is valued, thus increasing the warmth between the two siblings. This increase in warmth affirms that the individual has a support person in their sister, thus lowering their personal stress levels. Brothers' warmth was associated with higher sisters' stress and sisters' stress was associated with higher brothers' stress. This may indicate that if the sibling relationship is highly valued, i.e. has higher warmth, the transitions of emerging adulthood may constrain the relationship, which increases the stress experienced by the siblings. Finally, personal stress was associated with higher personal depression, furthering the importance of sibling relationships during this time period. These results indicate that the sibling relationship may be a crucial support figure during the transitional period of emerging adulthood. Future research should replicate these findings to further the field's understanding of sibling relationships and explore how the family of origin influences siblings. With continued research and investigation, interventions could be developed to foster sibling relationships to enhance their protective factors, especially during emerging adulthood.