The present paper was written under the auspices of the interdisciplinary research group "Educational Processes, Competence Development, and Selection Decisions at Preschool and Primary School Age (BiKS)" (FOR 543), funded by the German Research Foundation (DFG). The surveys were conceptualised and supervised as part of the developmental psychology sub-project (headed by S. Weinert) and the primary education sub-project (headed by H.-G. Roßbach). We would like to thank the German Research Foundation for funding the research group and the participating children, parents, early years educators, teachers, assistants, and members of staff for their commitment and cooperation.