„There is abundant evidence in sociology, but also in other disciplines, that substantial differences by SES (Anm.: SES = socioeconomic status) exist in language skills even before children enter elementary school.“
Univ.-Prof. Dr. Thorsten Schneider u. a., Development of socio-economic gaps in children’s language skills in Germany. In: Longitudinal and Life Course Studies, vol 13, no 1, 2022, S. 88.