A longitudinal study of Turkish-Dutch children’s language mixing in single-language settings: Language status, language proficiency, cognitive control and developmental language disorder

The aim of this study was to investigate the role of language status, language proficiency, cognitive control and Developmental Language Disorder (DLD) in bilingual Turkish-Dutch children’s language mixing in single-language settings. We investigated these factors over time following 31 children (20 with typical development, 11 with DLD), from the age of 5 or 6 years until they were 7 or 8 years old. Children more often mix the majority-societal language (Dutch) into the minority-heritage language (Turkish) than the other way around. Higher proficiency in Dutch, lower proficiency in Turkish, and having DLD are linked to more mixing in the Turkish setting. Effects of cognitive control on children’s language mixing are limited. Linguistic factors at a child-external and child-internal level impact on children’s mixing in single-language settings, and are more important than domain-general cognitive control. Increasing language proficiency in Turkish could explain why children mix less as they grow older.