Parent coaching at 6 and 10 months improves language outcomes at 14 months: A randomized controlled trial

Previous studies reveal an association between particular features of parental language input and advances in children's language learning. However, it is not known whether parent coaching aimed to enhance specific input components would (a) successfully increase these components in parents' language input and (b) result in concurrent increases in children's language development. The present randomized controlled trial assigned families of typically developing 6‐month‐old infants to Intervention (parent coaching) and Control (no coaching) groups. Families were equivalent on socioeconomic status, infants' gender, and infants' age. Parent coaching took place when infants were 6 and 10 months of age, and included quantitative and qualitative linguistic feedback on the amount of child‐directed speech, back‐and‐forth interactions, and parentese speech style. These variables were derived from each family's first‐person LENA recordings at home. Input variables and infant language were measured at 6, 10, and 14 months. Parent coaching significantly enhanced language input as measured by two social interaction variables: percentage of speech directed to the child and percentage of parentese speech. These two variables were correlated, and were both related to growth in infant babbling between 6 and 14 months. Intervention infants showed greater growth in babbling than Control infants. Furthermore, at 14 months, Intervention infants produced significantly more words than Control infants, as indicated by LENA recordings and parent report via the MacArthur‐Bates Communicative Developmental Inventory. Together, these results indicate that parent coaching can enrich specific aspects of parental language input, and can immediately and positively impact child language outcomes. A video of this article can be viewed at: https://youtu.be/7wqR28gPiwo Families of 6‐month old infants were randomly assigned to a Language Intervention (parent coaching) or Control (no coaching) group. Parent coaching took place when infants were 6 and 10 months old, and included quantitative and qualitative linguistic feedback on the amount of child directed speech, back‐and‐forth interactions, and parentese speech style, derived from the families' first‐person audio recordings at home. Parent coaching enhanced the production of child‐directed speech and parentese. Children of parents who received coaching showed enhanced language outcomes (more babbling and words) at 14 months.