Mabel L Rice1, Stephen R Zubrick2,3, Catherine L Taylor3,4, Lesa Hoffman1, Javier Gayán5. 1. Child Language Doctoral Program, University of Kansas, Lawrence. 2. Graduate School of Education, University of Western Australia, Perth. 3. The Telethon Kids Institute, Subiaco, Australia. 4. Centre for Child Health Research, The University of Western Australia, Perth. 5. Bioinfosol, Seville, Spain.
Abstract
Purpose: This study investigates the heritability of language, speech, and nonverbal cognitive development of twins at 4 and 6 years of age. Possible confounding effects of twinning and zygosity, evident at 2 years, were investigated among other possible predictors of outcomes. Method: The population-based twin sample included 627 twin pairs and 1 twin without a co-twin (197 monozygotic and 431 dizygotic), 610 boys and 645 girls, 1,255 children in total. Nine phenotypes from the same comprehensive direct behavioral assessment protocol were investigated at 4 and 6 years of age. Twinning effects were estimated for each phenotype at each age using general linear mixed models using maximum likelihood. Results: Twinning effects decreased from 4 to 6 years; zygosity effects disappeared by 6 years. Heritability increased from 4 to 6 years across all 9 phenotypes, and the heritability estimates were higher than reported previously, in the range of .44-.92 at 6 years. The highest estimate, .92, was for the clinical grammar marker. Conclusions: Across multiple dimensions of speech, language, and nonverbal cognition, heritability estimates are robust. A finiteness marker of grammar shows the highest inherited influences in this early period of children's language acquisition.
Purpose: This study investigates the heritability of language, speech, and nonverbal cognitive development of twins at 4 and 6 years of age. Possible confounding effects of twinning and zygosity, evident at 2 years, were investigated among other possible predictors of outcomes. Method: The population-based twin sample included 627 twin pairs and 1 twin without a co-twin (197 monozygotic and 431 dizygotic), 610 boys and 645 girls, 1,255 children in total. Nine phenotypes from the same comprehensive direct behavioral assessment protocol were investigated at 4 and 6 years of age. Twinning effects were estimated for each phenotype at each age using general linear mixed models using maximum likelihood. Results: Twinning effects decreased from 4 to 6 years; zygosity effects disappeared by 6 years. Heritability increased from 4 to 6 years across all 9 phenotypes, and the heritability estimates were higher than reported previously, in the range of .44-.92 at 6 years. The highest estimate, .92, was for the clinical grammar marker. Conclusions: Across multiple dimensions of speech, language, and nonverbal cognition, heritability estimates are robust. A finiteness marker of grammar shows the highest inherited influences in this early period of children's language acquisition.
Authors: Laura Segebart DeThorne; Nicole Harlaar; Stephen A Petrill; Kirby Deater-Deckard Journal: J Speech Lang Hear Res Date: 2012-01-09 Impact factor: 2.297
Authors: Mabel L Rice; Catherine L Taylor; Stephen R Zubrick; Lesa Hoffman; Kathleen K Earnest Journal: J Speech Lang Hear Res Date: 2020-03-12 Impact factor: 2.297
Authors: Philip S Dale; Sophie von Stumm; Saskia Selzam; Marianna E Hayiou-Thomas Journal: J Speech Lang Hear Res Date: 2020-04-28 Impact factor: 2.297
Authors: Michelle M Martel; Anjeli R Elkins; Ashley G Eng; Patrick K Goh; Pevitr S Bansal; Tess E Smith-Thomas; Melina H Thaxton; Peter Ryabinin; Michael A Mooney; Hanna C Gustafsson; Sarah L Karalunas; Joel T Nigg Journal: Res Child Adolesc Psychopathol Date: 2022-02-01