Receptive Vocabulary in Early Childhood: The Roles of Infant Attention, Toddler Effortful Control, and Working Memory

Abstract

Early childhood is marked by rapid communicative and linguistic growth, and early language skills are indicators of later linguistic ability and developmental outcomes, including academic achievement and self-regulation. Identifying early developmental factors that support language development is therefore critical. The present longitudinal study examined the indirect relation between infant attention and later receptive vocabulary and whether temperamental effortful control moderates the mediating role of working memory. Participants were 410 children from a community sample drawn from a larger longitudinal study. At 10-months, infants’ EEG-related attention and behavioral attention were assessed during baseline video. At 24-months, mothers completed the ECBQ to assess effortful control. At 36-months, working memory was measured using behavioral and parent-report indicators. At 48-months, receptive vocabulary was assessed using a standardized measure, the PPVT. Separate moderated mediation models using 10,000 bootstrap samples yielded nonsignificant results for both EEG-related and behavioral attention predicting receptive vocabulary at 48-months. Given these findings, exploratory analyses focused on behavioral attention during a glove puppet task at 10-months and receptive vocabulary at 36-months. The index of moderated mediation was significant, suggesting the indirect association between infant behavioral attention and receptive vocabulary via working memory varied as a function of effortful control. These findings suggest that certain child-level factors may play a critical role in individual differences in language outcomes, particularly given the well-established links between language and cognition.