Purpose: Researchers have previously shown that individual differences in measures of receptive language ability at age 12 are highly heritable. In the current study, the authors attempted to identify some of the genes responsible for the heritability of receptive language ability using a "genome-wide association" approach. Method: The…

Purpose: The authors of this article examined the etiology of developmental language impairment (LI) at 4 and 12 years of age, as well as the relationship between the 2. Method: Phenotypic and quantitative genetic analyses using longitudinal data from the Twins Early Development Study (Oliver & Plomin, 2007) were conducted. A total of 2,923…

Background: An association between children's early language development and their emotional and behavioural functioning is reported in the literature. The nature of the association remains unclear and it has not been established if such an association is found in a population-based cohort in addition to clinical populations. Methods: This study…

This study considered how far nonverbal cognitive, language and reading abilities are affected by common genetic influences in a sample of 312 typically developing Chinese twin pairs aged from 3 to 11 years. Children were individually given tasks of Chinese word reading, receptive vocabulary, phonological memory, tone awareness, syllable and rhyme…

Purpose: In the 2nd decade of life, language skills expand in both quantitative and qualitative ways. The etiology of these new skills and the relationships among them have been little explored. Method: Taking advantage of widespread access to inexpensive and fast Internet connections in the United Kingdom, we administered four Web-based measures…

Fragile X syndrome (FXS) is the leading inherited cause of intellectual disability. The syndrome is caused by a single gene mutation on the X chromosome. Although individual differences are large, most individuals with FXS display weaknesses across all language and literacy domains compared with peers of the same chronological age with typical…

Background: Fragile X syndrome (FXS) is the most common known inherited cause of intellectual disability, yet very few studies have explored the language comprehension skills of children with FXS. We examined the receptive vocabulary, grammatical morphology and syntax skills of boys with FXS (who were additionally classified as having autism,…

This study compared the receptive language of adolescents and young adults with either Down syndrome (n=25), fragile X syndrome (n=19), or mental age matched typically developing children (n=24). Individuals with the syndromes differed in relative achievements across the domains of receptive vocabulary, receptive syntax, nonverbal cognition, and…