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…

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…

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…

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…

Children learn what words mean from hearing words used across a variety of contexts. Understanding how different contextual distributions relate to the words young children say is critical because context robustly affects basic learning and memory processes. This study examined children's everyday experiences using naturalistic video recordings to…

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…

Children acquire extensive knowledge from others. Today, children receive information from not only people but also technological devices, like social robots. Two studies assessed whether young children appropriately trust technological informants. One hundred and four 3-year-olds learned the names of novel objects from either a pair of social…

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…

We investigated toddlers' phonological representations of common vowel-initial words that can take on multiple surface forms in the input. In French, liaison consonants are inserted and are syllabified as onsets in subsequent vowel-initial words, for example, petit /t/ éléphant [little elephant]. We aimed to better understand the impact on…

Children learn the words of their native language(s) from interactions with their caregivers. Although previous research has found that the language children hear during those interactions predicts vocabulary outcomes, few studies have investigated how qualitative features of social interactions work together to affect children's vocabulary…

Within a language, there is considerable variation in the pronunciations of words owing to social factors like age, gender, nationality, and race. In the present study, we investigate whether toddlers link social and linguistic variation during word learning. In Experiment 1, 24- to 26-month-old toddlers were exposed to two talkers whose front…

This study examines associations between stimulating-responsive social interactions with mothers and nonparental childcare providers during the first 3 years of life and children's vocabulary and mathematics skills through age 15 (N = 1,364). Additive relations were found in which more stimulating-responsive interactions with mothers and with…

Although research suggests that responsive interactions are imperative for language development, the advent of mobile technology means that parent-child exchanges are often fraught with unpredictable interruptions. Less clear is how these momentary breaks in responsiveness affect word learning. In this within-subjects design, 38 mothers taught…

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…

Young children who hear more child-directed speech (CDS) tend to have larger vocabularies later in childhood, but the specific characteristics of CDS underlying this link are currently underspecified. The present study sought to elucidate how the structure of language input boosts learning by investigating whether repetition of object labels in…