What are the fundamental skills that young children need to develop at the start of school for future academic success? While a large body of research shows strong links between cognitive skills (attention, memory, etc.) and academic skills on the one hand, and emotional skills on the other, in students from primary school to university, few studies have explored these links in children aged 3 to 6 in a school context. Researchers from the University of Geneva (UNIGE) and Valais University of Teacher Education, Switzerland (HEP-VS), in collaboration with teachers from Savoie in France and their pedagogical advisor, examined the links between emotion knowledge, cooperation, locomotor activity and numerical skills in 706 pupils aged 3 to 6. The results, to be read in the journal Scientific Reports, show for the first time that emotion knowledge, cooperative social behavior and locomotor activity are interrelated and associated with numerical skills. These results are in line with the political and scientific consensus on the importance of social-emotional skills in early schooling and suggest that locomotor activity should be added to these fundamental skills.