The number of U.S. children living in households with extended families has greatly increased in the last 4 decades. This demographic shift calls for a reevaluation of the impact of household size on children's development. Household density (HHD), measured as the ratio of people to bedrooms in a home, has been shown to negatively relate to…

Real-time attention coordination in parent-toddler dyads is often studied in tightly controlled laboratory settings. These studies have demonstrated the importance of joint attention in scaffolding the development of attention and the types of dyadic behaviors that support early language learning. Little is known about how often these behaviors…

As they develop into mature speakers of their native language, infants must not only learn words but also the sounds that make up those words. To do so, they must strike a balance between accepting speaker-dependent variation (e.g., mood, voice, accent) but appropriately rejecting variation when it (potentially) changes a word's meaning (e.g., cat…

Learning to walk leads to an increase in language abilities; however, the underlying mechanisms accounting for this relation remain unclear. Investigating the quality of early gait control may offer some insights. The purpose of this study was to: (1) quantify how 13-month-olds (n = 39; 39% male) and 24-month-olds (n = 39; 59% male) adapt gait…

The present study investigates the relation between language environment and language delay in 63 British-English speaking children (19 typical talkers (TT), 22 late talkers (LT), and 22 late bloomers (LB) aged 13 to 18 months. Families audio recorded daily routines and marked the new words their child produced over a period of 6 months. To…

Around their first birthdays, infants begin to point, walk, and talk. These abilities are appreciable both by researchers with strictly standardized criteria and caregivers with more relaxed notions of what each of these skills entails. Here, we compare the onsets of these skills and links among them across two data collection methods: observation…

Exposure to communicative gestures, through their parents' use of gestures, is associated with infants' language development. However, the mechanisms supporting this link are not fully understood. In adults, sensorimotor brain activity occurs while processing communicative stimuli, including both spoken language and gestures. Using…

Toddlerhood is marked by advances in several lexico-semantic skills, including improvements in the size and structure of the lexicon and increased efficiency in lexical processing. This project seeks to delineate how early changes in vocabulary size and vocabulary structure support lexical processing (Experiment 1), and how these three skills…

Sometime before their second birthday, many children have a period of rapid expressive vocabulary growth called the vocabulary spurt. Theories of the underlying mechanisms differ: Accumulator models emphasize the accumulation of experience with words over time to yield a spurtlike pattern, while cognitive models attribute the spurt to cognitive…

Both early childhood maternal language input and the quality of classroom instruction in elementary school have been shown to be important environmental supports in predicting children's literacy skill development. However, no studies have simultaneously examined these two environmental supports in relation to children's early language skills and…

The interplay between self-regulation related skills and language is well recognized in dynamic theories, but few empirical studies have tested it, especially in toddlers. The current study examines the bidirectional links between self-regulation related skills and expressive vocabulary in a longitudinal study during toddlerhood. Participants were…

Parent language input is a well-established predictor of child language development. Multisensory attention skills (MASks; intersensory matching, shifting and sustaining attention to audiovisual speech) are also known to be foundations for language development. However, due to a lack of appropriate measures, individual differences in these skills…

Research suggests foster children are at risk for poor language skills. One intervention, attachment and biobehavioral catch-up (ABC), was shown to successfully improve not only young foster children's attachment to their parents, but also their receptive vocabulary skills (Bernard et al., 2017; Raby et al., 2019). Given that language acquisition…

Receptive vocabulary development was examined in 313 children (151 girls; 78% White) as a function of infant attention and maternal education (66% of mothers held a college degree or higher). Attention was measured at 10 months using a dynamic puppet task and receptive vocabulary was measured at 3-, 4-, 6-, and 9 years of age using the Peabody…

Why do infants learn some words earlier than others? Many theories of early word learning focus on explaining how infants map labels onto concrete objects. However, words that are more abstract than object nouns, such as "uh-oh," "hi," "more," "up," and "all-gone," are typically among the first to…