The account that word learning starts in earnest during the second year of life, when infants have mastered the disambiguation skills, has recently been challenged by evidence that infants during the first year already know many common words. The preliminary ability to rapidly map and disambiguate linguistic labels was tested in Italian-speaking…

Developmental science has increasingly scrutinized how environmental hazards influence child outcomes, but few studies examine how contaminants affect disparities in early skill formation. Linking research on environmental inequality and early childhood development, this study assessed whether differences in exposure to neurotoxic lead explain…

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…

Preschool teachers' perceptions about relationships with students (teacher-child relationships [TCRs]) predict children's subsequent social competence (SC) and academic progress. Why this is so remains unclear. Do TCRs shape children's development, or do child attributes influence both TCRs and subsequent development? Relations between TCRs and…

In this study, infant vocabulary development was tracked in a multilingual society (Singapore) within a socioeconomically diverse sample. The sample comprised 1316 infants from 17.4 to 27.7 months (669 females, 647 males; 88% Chinese race, 4% Malay, 4% Indian, and 0.004% mixed-race [4% declined to provide race information]). Children varied in…

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…

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…

This study investigates associations between trajectories of children's vocabulary development and subsequent behavioral and emotional difficulties via two potential mediating mechanisms; literacy and peer problems. Nationally representative data from 4,983 Australian children were used to examine trajectories of receptive vocabulary (4-5, 6-7,…

Infants' pointing gestures are a critical predictor of early vocabulary size. However, it remains unknown precisely how pointing relates to word learning. The current study addressed this question in a sample of 108 infants, testing one mechanism by which infants' pointing may influence their learning. In Study 1, 18-month-olds, but not…

In response to Golinkoff, Hoff, Rowe, Tamis-LeMonda, and Hirsh-Pasek's (2018) commentary, we clarify our goals, outline points of agreement and disagreement between our respective positions, and address the inadvertently harmful consequences of the word gap claim. We maintain that our study constitutes a serious empirical challenge to the word…

This study investigates the relationship between early maternal employment history and children's vocabulary and inductive reasoning ability at age 5, drawing on longitudinal information on 2,200 children from the Growing Up in Scotland data. Prior research rarely addresses dynamics in maternal employment and the methodological ramifications of…

Sperry, Sperry, and Miller (2018) aim to debunk what is called the 30-million-word gap by claiming that children from lower income households hear more speech than Hart and Risley ([Hart, B., 1995]) reported. We address why the 30-million-word gap should not be abandoned, and the importance of retaining focus on the vital ingredient to language…

Despite evidence that young children are sensitive to differences in angle measure, older students frequently struggle to grasp this important mathematical concept. When making judgments about the size of angles, children often rely on erroneous dimensions such as the length of the angles' sides. The present study tested the possibility that…

The present study followed a sample of first-grade (N = 316, M[subscript age] = 7.05 at first test) through fourth-grade students to evaluate dynamic developmental relations between vocabulary knowledge and reading comprehension. Using latent change score modeling, competing models were fit to the repeated measurements of vocabulary knowledge and…

The purpose of this study was to empirically examine the dimensionality of language ability for young children (4-8 years) from prekindergarten to third grade (n = 915), theorizing that measures of vocabulary and grammar ability will represent a unitary trait across these ages, and to determine whether discourse skills represent an additional…