To mix or not to mix? The relation between parental language mixing and bilingual children’s language outcomes

Abstract Language mixing is a common phenomenon in the language input of bilingual children. However, the relation between the frequency of parental language mixing and children’s language development remains unclear. The present study investigates the relation between language mixing as observed in daylong audio recordings (LENA) and as reported by parents in the questionnaire for Quantifying Bilingual Experience (Q-BEx) and children’s language outcomes in the majority and minority language. Participants were 52 3-to-5-year-old Polish-Dutch and Turkish-Dutch children in the Netherlands and Bayesian informative hypothesis evaluations were applied. In 14 out of 15 regression analyses, the LENA and Q-BEx measures yielded similar associations with children’s language outcomes. Parental language mixing was not related to majority language outcomes, but a negative relation was found with expressive vocabulary in the minority language. Longitudinal studies are needed to pinpoint the directionality of this negative relation.