In societies where schooling is a compulsory developmental experience, as in Brazil, educational institutions are important contexts for the ontogenesis of human values and the construction of specific practices of self–other transactions. School contexts are of crucial importance for the reproduction and transformation of dominant social values. This chapter addresses the topic of cultural practices and values concerning relationships and interactions among developing individuals within schools, particularly highlighting the role of adults, peers, and activities. We show that what happens within school contexts is closely related to cultural practices and values that are also prevalent in contexts such as family and other social groups. The first section of this chapter elaborates on the topic of self–other relationships within schools as we discuss the cultural roots of educational psychology from a dialogical perspective. Next, we analyze social interaction patterns and cultural practices, as we elaborate on the ontogenesis and developmental perspectives regarding diversity, prejudice, competition versus cooperation, bullying, and the need for ethical positioning and moral actions within schools and society at large. The chapter explores the relationships between schools and other cultural contexts of Brazilian society whenever possible, and we provide empirical examples in which prejudice and bullying among students may have been encouraged—instead of inhibited—within educational settings. We highlight the absolute necessity of including such topics in a teacher´s professional trainings, as well as organizing a permanent in-service orientation. Last, but not least, we argue for the radical transformation of schools in order to construct inclusive contexts that are oriented to alterity—according to public "inclusion" policies—and organized to promote democratic, prosocial values, diversity acceptance, and cultural practices, which may improve the quality of school education in the contemporary world.