Most deaf children have hearing parents who do not know a sign language at birth and are at risk of limited language input during early childhood. Studying these children as they learn a sign language has revealed that timing of first-language exposure critically shapes language outcomes. But the input deaf children receive in their first language…

Previous studies have found correlations between parent input and child language outcomes, providing prima facie evidence for a causal relation. However, this could also reflect the effects of shared genes. The present study removed this genetic confound by measuring English vocabulary growth in 29 preschool-aged children (21 girls) aged…

Children learn words in environments where there is considerable variability, both in terms of the number of possible referents for novel words, and the availability of cues to support word-referent mappings. How caregivers adapt their gestural cues to referential uncertainty has not yet been explored. We tested a computational model of…

Most language use is displaced, referring to past, future, or hypothetical events, posing the challenge of how children learn what words refer to when the referent is not physically available. One possibility is that iconic cues that imagistically evoke properties of absent referents support learning when referents are displaced. In an…

Purpose: This study examines the influence of lexical and phonological factors on expressive lexicon size in 40 French-speaking children tested longitudinally from 22 to 48 months. The factors include those based on the lexical and phonological properties of words in the children's lexicons (phonetic complexity, word length, neighborhood density…

Object word learning can be based on infant-related factors such as their manual actions and socio-linguistic factors such as parental input. Specific input for spatial features (i.e., size, shape, features of objects) can be related to object word comprehension in early vocabulary development. In a longitudinal study, we investigated whether fine…

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…

Computers, laptops, digital tablets, and whiteboards are all commonly used technologies in classrooms today. The COVID-19 pandemic led to an increased use of digital technology to offer virtual learning and maintain social connections. Given the multifaceted nature of technology, the complexities of child development, and the increasing…

In order for children to understand and reason about the world in an adult-like fashion, they need to learn that conceptual categories are organized in a hierarchical fashion (e.g., a dog is also an animal). While children learn from their first-hand observation of the world, social knowledge transmission via language can also play an important…

This paper describes an investigation into the function of child-directed speech (CDS) across development. In the first experiment, 10-21-month-olds were presented with familiar words in CDS and trained on novel words in CDS or adult-directed speech (ADS). All children preferred the matching display for familiar words. However, only older toddlers…

A large body of research suggests that spoken language processing is heavily influenced by social characteristics of the speaker, and conversely, that socio-cognitive processing is influenced by the language spoken by our interlocutors. However, little is known about the extent to which this interaction that is observed in adulthood has its roots…

The National Institute for Early Education Research (NIEER) conducted a landscape evaluation of early childhood programs in Indiana (IN) between the spring of 2021 and the summer of 2022. Commissioned by Early Learning Indiana (ELI), this study provides Indiana programs and policymakers with research-based information on the quality of a sample of…

Toddlers from low-income and language-minority immigrant families are at risk for language difficulties due to early disparities in the quality of their home language environment. The present longitudinal study extends previous research by investigating nursery teachers' communicative modalities and functions, and their relations with the…

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…

The National Institute for Early Education Research (NIEER) conducted a landscape evaluation of early childhood programs in Indiana (IN) between the spring of 2021 and the summer of 2022. The evaluation included assessments of infant, toddler, and preschooler children's developmental status in multiple domains at two time points to measure growth.…