„SES-related (Anm.: SES = socio-economic status) disparities in language skills are not only found in preschool or school age children but are also evident in even younger children below the age of 3 years. For example, interrelations between parental education as well as occupation with vocabulary were already shown in 18-month-old children; and at the age of 24 months, a 6-month gap in language processing skills was evident.“
Dr. Manja Attig u. a., What Impacts Early Language Skills? Effects of Social Disparities and Different Process Characteristics of the Home Learning Environment in the First 2 Years (2020), S. 3.