The most long-lasting and enduring relationship an individual can develop is with a sibling. Considering their closeness in age and early association, siblings 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 seen to determine cognitive faculties, emotional balance, self-sufficiency, and peer interaction. Clarifying the complex processes of these relationships and the benefits of parental involvement, Avidan Milevsky provides a fou.