In this chapter, I integrate the previous conversation about the intersection of psychology, social justice, restorative justice, and peace education with what we understand about social and cognitive growth as they come of age. I open with broad theoretical lenses that describe the role and interconnection of varied systems in informing development, the particular importance of school contexts, and the ways young people are active agents in making sense of these influences. I then review what moral development can offer, as a wealth of theory and research describes how young people think about what is fair and just, build social and emotional skills, and think about who they are themselves. I link moral development with restorative justice before doing the same for peace education. Each area also brings identity development and meaning making into the conversation, with which I intend to lay the groundwork for the theoretical framework of conceptualized peace. In the final section, I summarize key questions that remain, such as balancing individual agency and contextual influence or the complexity of human development, to help motivate where we are going in the next chapter.