title: Genetic influences in different aspects of language development: the etiology of language skills in 4.5-year-old twins.
abstract: 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 range. A similar pattern was found at the low end of the distribution with the exception of two receptive measures. Environmental influence was mainly due to nonshared factors, unique to the individual, with little influence from shared environment for most measures. Genetic and environmental influences on language ability and disability are quantitatively and qualitatively similar for males and females.
authors.affiliation: Social, Genetic, and Developmental Psychiatry, Institute of Psychiatry, London. England. y.kovas@iop.kcl.ac.uk
authors.forename: Yulia
authors.initials: Y
authors.lastname: Kovas
authors.forename: Marianna E
authors.initials: ME
authors.lastname: Hayiou-Thomas
authors.forename: Bonamy
authors.initials: B
authors.lastname: Oliver
authors.forename: Philip S
authors.initials: PS
authors.lastname: Dale
authors.forename: Dorothy V M
authors.initials: DV
authors.lastname: Bishop
authors.forename: Robert
authors.initials: R
authors.lastname: Plomin
mesh_terms: D002675:Child, Preschool; D005260:Female; D005838:Genotype; D006801:Humans; D007206:Individuality; D007804:Language Development; D008137:Longitudinal Studies; D008297:Male; D010641:Phenotype; D010700:Phonetics; D012660:Semantics; D012931:Social Environment; D013062:Speech Articulation Tests; D013067:Speech Perception; D013223:Statistics as Topic; D014429:Twins, Dizygotic / Q000235:genetics*; D014430:Twins, Monozygotic / Q000235:genetics*; D014705:Verbal Behavior; D014706:Verbal Learning