„From a longitudinal perspective, grade retention and repetition do not seem to be purposeless; our results indicate its effectiveness, starting already in the year of grade repetition. Even if a grade retention decision may initially be experienced by students as a critical event, it seems to be associated longitudinally with a fast adaptation to peers and circumstances in the new class as well as further developmental opportunities, e.g., an improvement in school performance.“
Prof. Dr. Katharina Rathmann u.a., Critical Events throughout the Educational Career: The Effect of Grade Retention and Repetition on School-Aged Children’s Well-Being (2020), S. 20.