Longitudinal Study of Language and Speech of Twins at 4 and 6 Years: Twinning Effects Decrease, Zygosity Effects Disappear, and Heritability Increases

Autor/inn/en	Rice, Mabel L.; Zubrick, Stephen R.; Taylor, Catherine L.; Hoffman, Lesa; Gayán, Javier
Titel	Longitudinal Study of Language and Speech of Twins at 4 and 6 Years: Twinning Effects Decrease, Zygosity Effects Disappear, and Heritability Increases
Quelle	In: Journal of Speech, Language, and Hearing Research, 61 (2018) 1, S.79-93 (15 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	1092-4388
Schlagwörter	Longitudinal Studies; Genetics; Twins; Cognitive Development; Language Acquisition; Vocabulary; Grammar; Vocabulary Development; Foreign Countries; Intelligence Tests; Verbal Ability; Maturity (Individuals); Intelligence Quotient; Correlation; Language Skills; Speech Skills; Language Impairments; Preschool Children; Statistical Analysis; Australia; Peabody Picture Vocabulary Test; Columbia Mental Maturity Scale; Goldman Fristoe Test of Articulation + Suchen Sie Ihr Suchwort? Longitudinal study; Longitudinal method; Longitudinal methods; Längsschnittuntersuchung; Humangenetik; Twin; Zwilling; Kognitive Entwicklung; Sprachaneignung; Spracherwerb; Wortschatz; Grammatik; Wortschatzarbeit; Ausland; Intelligence test; Intelligenztest; Mündliche Leistung; Reifung; Intelligenzquotient; Korrelation; Language skill; Sprachkompetenz; Sprachfertigkeit; Speech disorder; Speech disorders; Speech disabilities; Speech disability; Speech handicap; Speech handicaps; Speech impairment; Speech impairments; Language handicaps; Sprachbehinderung; Pre-school age; Preschool age; Child; Children; Pre-school education; Preschool education; Vorschulalter; Kind; Kinder; Vorschulkind; Vorschulkinder; Vorschulerziehung; Vorschule; Statistische Analyse; Australien
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 0.44-0.92 at 6 years. The highest estimate, 0.92, 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. (As Provided).
Anmerkungen	American Speech-Language-Hearing Association. 2200 Research Blvd #250, Rockville, MD 20850. Tel: 301-296-5700; Fax: 301-296-8580; e-mail: slhr@asha.org; Web site: http://jslhr.pubs.asha.org
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01