During word learning moments, toddlers experience labels and objects in particular environments. Do toddlers learn words better when the physical environment creates contrasts between objects with different labels? Thirty-six 21- to 24-month-olds (92% White, 22 female, data collected 8/21-4/22) learned novel words for novel objects presented using…

Others' emotional expressions affect individuals' attention allocation in social interactions, which are integral to the process of word learning. However, the impact of perceived emotions on word learning is not well understood. Two eye-tracking experiments investigated 78 British toddlers' (37 girls) of 29- to 31-month-old retention of novel…

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…

Learning about emotions is an important part of children's social and communicative development. How does children's emotion-related vocabulary emerge over development? How may emotion-related information in caregiver input support learning of emotion labels and other emotion-related words? This investigation examined language production and input…

Children's ability to recognize object shape is foundational for successful early word learning. However, the prototypical shape of objects may not be easily accessible--take margarita glasses, for instance. The current study examined 304 U.S. children 17- to 42-month-old (152 females) from 2017 to 2020, asking how shape, age, and vocabulary…

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…

Previous work indicates mutual exclusivity in word learning in monolingual, but not bilingual toddlers. We asked whether this difference indicates distinct conceptual biases, or instead reflects best-guess heuristic use in the absence of context. We altered word-learning contexts by manipulating whether a familiar- or unfamiliar-race speaker…

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…

Adults create and update predictions about what speakers will say next. This study asks whether prediction can drive language acquisition, by testing whether 3- to 4-year-old children (n = 45) adapt to recent information when learning novel words. The study used a syntactic context which can precede both nouns and verbs to manipulate children's…

Amid growing controversy about the oft-cited "30-million-word gap," this investigation uses language data from five American communities across the socioeconomic spectrum to test, for the first time, Hart and Risley's (1995) claim that poor children hear 30 million fewer words than their middle-class counterparts during the early years…

Although the size of a child's vocabulary associates with language-processing skills, little is understood regarding how this relation emerges. This investigation asks whether and how the structure of vocabulary knowledge affects language processing in English-learning 24-month-old children (N = 32; 18 F, 14 M). Parental vocabulary report was used…

In some areas of rural Africa, long-standing cultural traditions and beliefs may discourage parents from verbally engaging with their young children. This study assessed the effectiveness of a parenting program designed to encourage verbal engagement between caregivers and infants in Wolof-speaking villages in rural Senegal. Caregivers (n = 443)…

This study examined the relation of 3-year core information-processing abilities to lexical growth and development. The core abilities covered four domains--memory, representational competence (cross-modal transfer), processing speed, and attention. Lexical proficiency was assessed at 3 and 13 years with the Peabody Picture Vocabulary Test (PPVT)…

Recent evidence has suggested that sleep may facilitate language learning. This study examined variation in language ability in 29 toddlers with Down syndrome (DS) in relation to levels of sleep disruption. Toddlers with DS and poor sleep (66%, n = 19) showed greater deficits on parent-reported and objective measures of language, including…