Social competence in school-age children is a longitudinal project that studies the stability and change of socially competent behavior during the schoolyears. We followed 8-year-old children from grade 2 to grade 4, in parallel with 10-year-old children from grade 4 to grade 6. The aim of the study was to provide a better understanding of how children’s individual characteristics and skills develop and interact in order to understand more about their social interactions with others and the development of successful social relationships. The focus was on the relation between the child's temperament, cognitive development and social behavior. In particular, the longitudinal association between emotionality and emotion regulation, empathic concern, social perspective-taking skills and prosocial behavior.