Infants and toddlers in the United States with more close relationships have larger vocabularies.

Young children learn language from their caregivers, family members, and friends. However, with few exceptions, contemporary developmental scientists have studied language input and language learning through the lens of the primary caregiver and the nuclear family, rather than the infants' broader communities. In many communities-and increasingly in the United States-nonnuclear family structures are common, and extended kin, fictive kin, and intergenerational relationships are relied upon for child care. Understanding children's relationships within kinship networks can allow for more inclusive depictions of children's social interactions and their language experiences. We drew upon methods used by researchers studying social networks to assess U.S. infants' and toddlers' network composition. Results showed that young children with a greater number of close relationships (but not those with larger networks overall) had larger vocabularies, after controlling for age and socioeconomic status. These findings suggest that distributed models of child-rearing are an influential factor in early language growth and call for increased attention to social networks for understanding children's developmental trajectories. (PsycInfo Database Record (c) 2024 APA, all rights reserved).