Early Parental Knowledge and Parent-Child Conversations Promote Preschool Language Skills: A Randomized Controlled Trial.

Objective: This randomized controlled trial examined the long-term impact of the 3Ts-HV intervention on preschool-aged children's language skills through promoting parental knowledge and parent-child conversational turns during toddlerhood among families from low-socioeconomic status backgrounds, controlling for parental education level, parental language skills, and child's age.

Methods: Ninety two parent-toddler dyads of low socioeconomic status were randomized to receive either the 3Ts-HV intervention (n = 46) or Healthy Lifestyle control (n = 46) curriculum from 14 to 20 months. Parental language skills were assessed at 14 months; parental knowledge was assessed at 14 and 26 months; parent-child conversational turn count was assessed at 14 and 38 months; children's language skills were assessed at 50 months.

Results: A significant serial mediation effect (β = 0.05, 95% CI [0.002; 0.13]) revealed that the 3Ts-HV intervention increased parental knowledge at 26 months, contributed to more frequent parent-child conversational turns at 38 months, and in turn promoted children's language skills at 50 months.

Conclusions: The present study provides empirical evidence illustrating the underlying longitudinal processes from increasing parental knowledge and enriching parent-child linguistic interactions during toddlerhood, to promoting children's language development at preschool age. These findings point to a significant path to supporting families who face socioeconomic challenges early in life to promote equity in children's early language experiences and narrow disparities in children's developmental outcomes.