title: How specific is second language-learning ability? A twin study exploring the contributions of first language achievement and intelligence to second language achievement.
abstract: Learning a second language is crucially important in an increasingly global society, yet surprisingly little is known about why individuals differ so substantially in second language (SL) achievement. We used the twin design to assess the nature, nurture and mediators of individual differences in SL achievement. For 6263 twin pairs, we analyzed scores from age 16 UK-wide standardized tests, the General Certificate of Secondary Education (GCSE). We estimated genetic and environmental influences on the variance of SL for specific languages, the links between SL and English and the extent to which the links between SL and English are explained by intelligence. All SL measures showed substantial heritability, although heritability was nonsignificantly lower for German (36%) than the other languages (53-62%). Multivariate genetic analyses indicated that a third of genetic influence in SL is shared with intelligence, a third with English independent of intelligence and a further third is unique to SL.
authors.affiliation: King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Rimfeld
authors.affiliation: Department of Speech and Hearing Sciences, University of New Mexico, Albuquerque, NM, USA.
authors.forename: P S
authors.initials: PS
authors.lastname: Dale
authors.affiliation: King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, London, UK.
authors.forename: R
authors.initials: R
authors.lastname: Plomin
mesh_terms: D000293:Adolescent; D004522:Educational Status; D005260:Female; D040941:Heredity; D006801:Humans; D007360:Intelligence; D007802:Language; D007807:Language Tests; D008297:Male; D019303:Multilingualism; D012931:Social Environment; D014427:Twins / Q000193:education / Q000235:genetics / Q000523:psychology; D006113:United Kingdom; D014706:Verbal Learning / Q000502:physiology*