Does mixing age groups in early childhood education settings support children's language development?

The aim of the study is to investigate and strengthen understanding of the effects of age distribution in kindergarten departments with regard to children’s language development, and especially their vocabulary development. The study investigates the relationship between age difference in the departments and the effect this has on children’s vocabulary development. The research question is: To what extent is variation in age distribution in kindergarten departments linked to vocabulary development?

The study estimates that age gaps may be appropriate for children’s language development, but also that excessive age gaps may have a negative effect on language development and vocabulary development. The findings indicate a significant nonlinear relationship between the age of the children in the group and children’s vocabulary development. The largest gain in vocabulary development was found in kindergarten groups that had a maximum age difference of 24 months between the children. The results encourage political efforts to expand educational programmes for kindergarten teachers.

Theoretical and empirical evidence indicates that children’s linguistic development can be affected by the age of the other children in the group. This study investigates the relationship between age variation in groups of children and children’s vocabulary development for 2743 Danish children who were between two years and 9 months old and up to 6 years and 11 months old when the investigation was conducted. Approximately 10% of the children were considered immigrants, with the majority coming from Eastern Europe or the Middle East. All participating children attended public kindergartens in Denmark.

Justice, L. M., Logan, J. A., Purtell, K., Bleses, D. & Højen, A, (2019). "Does mixing age groups in early childhood education settings support children's language development?". Applied Developmental Science, 23(3):214-226.