Humans can attribute beliefs to others. However, it is unknown to what extent this ability results from an innate biological endowment or from experience accrued through child development, particularly exposure to language describing others' mental states. We test the viability of the language exposure hypothesis by assessing whether models…

This study aimed to determine the effects of the Active Early Learning (AEL) childcare center-based physical activity intervention on early childhood executive function and expressive vocabulary via a randomized controlled trial. Three-hundred-and-fourteen preschool children (134 girls) aged 3-5 years from 15 childcare centers were randomly…

The study sought to understand the general trajectory of children's executive function, as well as whether there was heterogeneity among monolingual English-speaking and dual language learning children in their growth of executive function. In addition, the study examined whether monolingual English-speaking and dual language learning children…

Children with delays in expressive language (late talkers) have heterogeneous developmental trajectories. Some are late bloomers who eventually "catch-up," but others have persisting delays or are later diagnosed with developmental language disorder (DLD). Early in development it is unclear which children will belong to which group. We…

Parents with fewer educational and economic resources (low socioeconomic-status, SES) tend to speak less to their children, with consequences for children's later life outcomes. Despite this well-established and highly popularized link, less research addresses why the SES "word gap" exists. Moreover, while research has assessed…

This study investigates the influence of semantic maturation on early lexical development by examining the impact of contextual diversity--known to influence semantic development--on word promotion from receptive to productive vocabularies (i.e., comprehension-expression gap). Study 1 compares the vocabularies of 3685 American-English-speaking…

Shared intentionality theory posits that at age 3, children expand their conception of plural agency to include 3- or more-person groups. We sought to determine whether this conceptual shift is detectable in children's pronoun use. We report the results of a series of Bayesian hierarchical generative models fitted to 479 English-speaking…

This study aims to compare the effects of "questioning with minimal evaluation" (PE) and "prompt-evaluate-expand-repeat" (PEER) used in dialogic reading (DR) on children's language development. This study included 119 typically developing (TD) and 107 Chinese children with autism spectrum disorder (ASD) by using a pre- and…

This research takes a dyadic approach to study early word learning and focuses on toddlers' (N = 20, age: 17-23 months) "information seeking" and parents' "information providing" behaviors and the ways the two are coupled in real-time parent-child interactions. Using head-mounted eye tracking, this study provides the first…

Bilingual environments are more complex than monolingual environments. To adapt to this complexity, bilingual infants may navigate their environment in fundamentally different ways than monolingual infants. Drawing from visual, social, and linguistic processing, in this article, I present evidence to suggest that bilingual and monolingual learners…

Infants show shifting patterns of visual engagement to faces over the first years of life. To explore the adaptive implications of this engagement, we collected eye-tracking measures on cross-sectional samples of 10-25-month-old typically developing toddlers (TD;N = 28) and those with autism spectrum disorder (ASD;N = 54). Concurrent language…

Vocabulary checklists completed by caregivers are a common way of measuring children's vocabulary knowledge. We provide evidence from checklist data from 31 children with and without autism spectrum disorder. When asked to report twice about whether or not their child produces a particular word, caregivers are largely consistent in their…

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 article presents data on lexical development of 881 Israeli Hebrew-speaking monolingual toddlers ages 1;0 to 2;0. A Web-based version of the Hebrew MacArthur-Bates Communicative Development Inventories (H-MB-CDI) was used for data collection. Growth curves for expressive vocabulary, receptive vocabulary, actions and gestures were…

As a spoken word unfolds over time, similar sounding words ("cap" and "cat") compete until one word "wins". Lexical competition becomes more efficient from infancy through adolescence. We examined one potential mechanism underlying this development: lexical inhibition, by which activated candidates suppress…