The persistence of intergroup conflicts around the world creates urgency for research on child development in such settings. Complementing what we know about internalizing and externalizing developmental outcomes, in this article, I shift the focus to children's prosocial behaviors and more specifically, the Developmental Peacebuilding Model (DPM). The DPM makes three main contributions: It (a) integrates a developmental intergroup framework and socioecological perspective with a peace-building paradigm to examine the target and type of children's prosocial behavior in settings of intergroup conflict; (b) outlines how children's outgroup prosocial behaviors, which promote constructive change at different levels of social ecology, can be understood as peace building and fostering social cohesion; and (c) has implications for research and global policy. KEYWORDS-prosocial behavior; intergroup conflict; children; adolescents; youth; Developmental Peacebuilding Model; helping; civic engagement; social ecology; social cohesion Globally, armed intergroup conflicts have both increased and intensified since the end of World War II, exposing more children to political violence. More than 60% of such conflicts reoccur (Gates, Mokleiv, & Trappeniers, 2016), illustrating that the seed of future violence is sown even as a peace accord is signed. Moreover, political intergroup conflicts-those based in ethnic, religious, and racial differences (Tropp, 2012)-are particularly difficult to address. This startling reality calls for research into the cyclical nature of war and conflict and in particular, the role of children. Complementing the growing body of research on the negative impact of political violence on children (Cummings, Merrilees, Taylor, & Mondi, 2017), in this article, I shift the focus to the potential constructive impact children can have on the conflict around them (