Variability in children's language acquisition is likely due to a number of cognitive and social variables. The current study investigated whether individual differences in statistical learning (SL), which has been implicated in language acquisition, independently predicted 6- to 8-year-old's comprehension of syntax. Sixty-eight (N = 68)…

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…

Generics ("'Dogs' bark") convey important information about categories and facilitate children's learning. Two studies with parents and their 2- or 4-year-old children (N = 104 dyads) examined whether individual differences in generic language use are as follows: (a) stable over time, contexts, and domains, and (b) linked…

Using online measures of familiar word recognition in the looking-while-listening procedure, this prospective longitudinal study revealed robust links between processing efficiency and vocabulary growth from 18 to 30 months in children classified as typically developing (n = 46) and as "late talkers" (n = 36) at 18 months. Those late talkers who…

Although the research literature regarding language growth trajectories is burgeoning, the shape and direction of English Language Learners' (ELLs) language growth trajectories are largely not known. This study used growth curve modeling to determine the shape of ELLs' language growth trajectories across 12,248 oral narrative language samples…

Imitation, vocabulary, pretend play, and socially insightful behavior were investigated in 5,206 same- and opposite-sex 2-year-old twin pairs in the United Kingdom. Individual differences in imitative ability were due to modest heritability (30%), while environmental factors shared between twins (42%) and unique to each twin (28%) also made…

Assessments of temperament, emotion, cognition, and language acquisition were obtained for 200 pairs of 14-month-old twins. Comparisons between the assessment correlations for identical and fraternal twins indicated an influence of genetics on inhibition, activity, temperament, empathy, negative emotion, spatial memory, categorization skills, and…

Presents data showing that the MacArthur Communicative Development Inventory's (CDI) large variability, lack of stability, and insufficient ability to predict early language delay are authentic reflections of individual differences in early language development rather than measurement deficiencies. Responds to critiques regarding sociodemographic…

Research suggests that children with specific language impairment (SLI) have processing limitations; however, the mechanisms involved have not been well defined or investigated in a theory-guided manner. The theory of constructive operators was used as a framework to explore processes underlying limited processing capacity in children with SLI.…

Investigated birth-order differences in children's early vocabulary development. Compared the composition and age of acquisition of the first 50 and 100 words of 9 firstborns and their younger siblings, using a longitudinal maternal diary methodology. A small but significant birth-order effect was found for the age at which the 50-word milestone…

The language development of monozygotic twins, same-sex dizygotic twins, siblings of monozygotic twins, and siblings of dizygotic twins, ages 3-17, was studied to estimate how much of the individual variation in children's language skills results from genetic factors and how much from environmental experience. (BRT)

Quantitative growth curve models for estimating individual developmental functions from various types of longitudinal data are discussed in the context of investigator assumptions and research design characteristics. Linear and nonlinear models that estimate growth curves are illustrated, and contrasted when they are fit to speech development…

Examined how child and family factors influence individual differences in the language development of African-American children between 18 and 30 months of age. Found that vocabulary and utterance length increased linearly. Children from more stimulating and responsive homes had larger vocabularies, used more irregular nouns and verbs, and had…