Julia Kretschmann, Andrea Westphal, Miriam Vock

• Several studies have revealed that older students in a year group reach higher achievement scores than younger students in that group. But less is known about how students' relative age in class relates to their self-perception of academic achievement, their social acceptance in class and to how teachers judge their abilities. Therefore, we examined relative age effects within class on students' academic self-concept, peer relations, grades, and teachers' secondary school recommendation. Analyses were based on a sample of N = 18,956 German fourth graders, who had never been retained or accelerated. We applied multilevel regression to control for covariates at the individual and classroom level. There were no substantial relative age effects within class across any of the outcomes, except for a small advantage for the youngest in their reading self-concept. Our findings therefore contradict the common assumption that younger students in class are disadvantaged compared to their older classmates.