Consonants and vowels differentially contribute to lexical acquisition. From 8 months on, infants' preferential reliance on consonants has been shown to predict their lexical outcome. Here, the predictive value of German-learning infants' (n = 58, 29 girls, 29 boys) trajectories of consonant and vowel perception, indicated by the…

The current study investigated whether age-related changes in the conceptualization of social groups influences interpretation of the pronoun we. Sixty-four 2- and 4-year-olds (N = 29 female, 50 White-identifying) viewed scenarios in which it was ambiguous how many puppets performed an activity together. When asked who performed the activity, a…

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…

Similes require two different pragmatic skills: appreciating the intended similarity and deriving a scalar implicature (e.g., "Lucy is like a parrot" normally implies that Lucy is not a parrot), but previous studies overlooked this second skill. In Experiment 1, preschoolers (N = 48; ages 3-5) understood "X is like a Y" as an…

Individual differences in infants' native phonological development have been linked to the quantity and quality of infant-directed speech (IDS). The effects of parental and infant bilingualism on this relation in 131 five- and nine-month-old monolingual and bilingual Spanish and Basque infants (72 male; 59 female; from white middle-class…

This study investigates the impact of evidentiality on source monitoring and the impact of source monitoring on false belief understanding (FBU), while controlling for short-term memory, age, gender, and receptive vocabulary. One hundred (50 girls) monolingual 3- and 4-year-olds from Turkey and the UK participated in the study in 2019. In Turkish,…

Grouping children of different ages in the same preschool classroom (i.e., mixed age) is widespread, but the evidence supporting this practice is mixed. A factor that may play a role in the relation between classroom age composition and child outcomes is peer skill. This study used a sample of 6,338 preschoolers (ages 3-5) to examine the influence…

Daylong at-home audio recordings from 10 Tseltal Mayan children (0;2-3;0; Southern Mexico) were analyzed for how often children engaged in verbal interaction with others and whether their speech environment changed with age, time of day, household size, and number of speakers present. Children were infrequently directly spoken to, with most…

Interventions that train parents to share picture books with children are seen as a strategy for supporting child language development. We conducted meta-analyses using robust variance estimation modeling on results from 19 RCTs (N[subscript total] = 2,594; M[subscript child age] = 1-6 years). Overall, book-sharing interventions had a small sized…

This study took a novel approach to understanding the role of language in spatial development by combining approaches from spatial language and gesture research. It analyzed forty-three 4.5- to 6-year-old's speech and gesture production during explanations of reasoning behind performance on Spatial Analogies and Children's Mental Transformation…

A double-blind randomized controlled trial of n-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation or matching placebo during third trimester of pregnancy was conducted within the COPSAC[subscript 2010] mother-child cohort consisting of 736 women and their children. The objective was to determine if maternal n-3 LCPUFA pregnancy…

This study employs the Specificity Principle to examine the relative impacts of external (input quantity at home and at school, number of books and reading frequency at home, teachers' degree and experience, language usage, socioeconomic status) and internal factors (children's working memory, nonverbal intelligence, learning-related…

Although most studies of language learning take place in quiet laboratory settings, everyday language learning occurs under noisy conditions. The current research investigated the effects of background speech on word learning. Both younger (22- to 24-month-olds; n = 40) and older (28- to 30-month-olds; n = 40) toddlers successfully learned novel…

Category-based induction is a hallmark of mature cognition; however, little is known about its origins. This study evaluated the hypothesis that category-based induction is related to semantic development. Computational studies suggest that early on there is little differentiation among concepts, but learning and development lead to increased…

Using an epidemiological sample (N = 1,117) and a prospective longitudinal design, this study tested the direct and indirect effects of preverbal and verbal communication (15 months to 3 years) on executive function (EF) at age 4 years. Results indicated that whereas gestures (15 months), as well as language (2 and 3 years), were correlated with…