Anxo Sanchez. In this talk I will present the results of a study on networks of relationships we have been conducting with high schools since 2018. Our rich dataset allows us to answer both structural and dynamical (longitudinal) questions.From a more structural viewpoint, I will discuss how the features of the network reflect and influence the characteristics of the school, and I will show how the existence of a relationship can be predicted with great accuracy both from a microscopic and a microscopic viewpoint. On the side of the dynamics, I will provide evidence of the stability of the results along several years and I will show how the Dunbar’s circle structure can be seen in the dynamics of the relationships. Leveraging on the information on negative relationships, I will discuss the theory of social balance in light of our observations and our structural knowledge. Our results provide important insights in our quest for a theory that shows how the individual “social atoms” merge onto the network of society.