Vocabulary input frequency influences age of acquisition, and is also an essential control for investigating the influence of other factors. We propose a new method of frequency estimation, self-report. 918 Danish-speaking parents of 12-36-month-old children estimated their frequency of use of 725 words. Self-report was substantially correlated…

Studies examining factors that influence when words are learned typically investigate one lexical category or a small set of words. We provide the first evaluation of the relation between input frequency and age of acquisition for a large sample of words. The MacArthur-Bates Communicative Development Inventory provides norming data on age of…

Prediction from early development to later achievement has the potential to improve clinical and educational service delivery as well as to inform developmental theory. In this longitudinal study, we asked how well can educational achievement measured in the final year (Grade 9, age 15) of compulsory education--both overall and for outcomes in the…

Purpose: Language acquisition is predictive of successful reading development, but the nature of this link is poorly understood. Method: A sample of 7,179 twin pairs was assessed on parent-report measures of syntax and vocabulary at ages 2, 3, and 4 years and on teacher assessments of reading achievement (RA) at ages 7, 9, and 10 years. These…

Parent report has proven a valid and cost-effective means of evaluating early child language. Norming datasets for these instruments, which provide the basis for standardized comparisons of individual children to a population, can also be used to derive norms for the acquisition of individual words in production and comprehension and also early…

The fact that early lexical and grammatical acquisition are strongly correlated has been cited as evidence against the view that the language faculty is composed of dissociable and autonomous modules (Bates & Goodman, 1997). However, previous studies have not yet eliminated the possibility that lexical-grammar associations may be attributable to…

Two cohorts of same-sex twin pairs were assessed on grammar and vocabulary. Findings indicated that vocabulary and grammar correlated strongly at 2 and 3 years in both cohorts, with a consistently high genetic correlation between vocabulary and grammar at both ages. Findings suggest that the same genetic influences operate for vocabulary and…

The MacArthur-Bates Communicative Development Inventories (CDI; Dale, 1996; Fenson et al., 1994), parent reports about language skills, are being used increasingly in studies of theoretical and public health importance. This study (N=113) correlated scores on the CDI at ages 2 and 3 years with scores at age 3 years on tests of cognition and…

Assessed the language development of 2,898 pairs of 2-year-old twins born in England and Wales using the MacArthur Communicative language Development Inventory, which assesses vocabulary and grammar. Moderate heritabilities were found for both. (Author/VWL)

A study involving 32 children with language delays investigated the effectiveness of Dialogic Reading, an interactive language-facilitation technique. After adult instruction in Dialogic Reading, children spoke more, made longer utterances, produced more words, and participated more in shared book reading. No differences were found in vocabulary…

Parent-based assessments of vocabulary, grammar, nonverbal ability, and use of language to refer to past and future were obtained for 8,386 twins at age 2. Of the children who had early language delay, 44.1% had persisting language difficulties at 3 years and 40.2% had persisting language difficulties at 4 years. (Contains references.) (CR)

Japanese provides a valuable contrast for crosslinguistic studies of noun and verb dominance in early child language, and the effect of input on the early lexicon. In this study, 31 Japanese children between 1;0 and 2;0 and their caregivers were recorded in two contexts: joint bookreading and play with toys. Context had the largest effect, as…

The genetic and environmental etiologies of diverse aspects of language ability and disability, including articulation, phonology, grammar, vocabulary, and verbal memory, were investigated in a U.K. sample of 787 pairs of 4.5-year-old same-sex and opposite-sex twins. Moderate genetic influence was found for all aspects of language in the normal…

A study involving 356 twin pairs with early language delay found environmental influences shared by both twins were more substantial than genetic factors. Heritability was significantly higher in those with persisting difficulties but only when assessed in terms of parental concern at 3 years or professional involvement at 4 years. (Contains…