This paper focuses on group dynamics in the multiethnic school and their implications for students' social-emotional integration and development. The study examines the history of schooling in Italy, with particular attention to the transition towards a multi-ethnic school. In addition, the role of intelligence tests in school and the criticisms associated with them are analysed. Another important area of investigation concerns the phenomenon of migration in Italy and its history, as well as the effects of migration on individuals and society. In particular, it examines the integration process of migrants in the Italian school and the challenges they can face in their psycho-social adaptation. The development of the social self and the identity of the migrant are further explored, using the theory of self discrepancy and the theory of social perception. The role of categorization and stereotypes in social perception and in the formation of social patterns is also analysed. The second part of the study focuses on group dynamics, including conformity, obedience and social identity. It examines the basic principles of Social Identity theory (Tajfel, 1979) and social influence both by the majority and by the minority. Finally, interactions in groups are explored, with a focus on prejudice and its manifestations, including those at a young age. The goal is to understand group dynamics in the multi-ethnic school in order to promote integration and create an inclusive environment for all students. Through an in-depth analysis of current theories and research in the field of social psychology, this thesis provides a comprehensive overview of group dynamics in the multiethnic school and offers suggestions for interventions and strategies aimed at fostering student integration and well-being.