The genetic architecture of oral language, reading fluency, and reading comprehension: A twin study from 7 to 16 years

Maria G. Tosto, Marianna E. Hayiou-Thomas*, Nicole Harlaar, Elizabeth Prom-Wormley, Philip S. Dale, Robert Plomin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


This study examines the genetic and environmental etiology underlying the development of oral language and reading skills, and the relationship between them, over a long period of developmental time spanning middle childhood and adolescence. It focuses particularly on the differential relationship between language and two different aspects of reading: reading fluency and reading comprehension. Structural equation models were applied to language and reading data at 7, 12, and 16 years from the large-scale TEDS twin study. A series of multivariate twin models show a clear patterning of oral language with reading comprehension, as distinct from reading fluency: significant but moderate genetic overlap between oral language and reading fluency (genetic correlation r g = .46-.58 at 7, 12, and 16) contrasts with very substantial genetic overlap between oral language and reading comprehension (r g = .81-.87, at 12 and 16). This pattern is even clearer in a latent factors model, fit to the data aggregated across ages, in which a single factor representing oral language and reading comprehension is correlated with-but distinct from-a second factor representing reading fluency. A distinction between oral language and reading fluency is also apparent in different developmental trajectories: While the heritability of oral language increases over the period from 7 to 12 to 16 years (from h² = .27 to .47 to .55), the heritability of reading fluency is high and largely stable over the same period of time (h² = .73 to .71 to .64). (PsycINFO Database Record

Original languageEnglish
Pages (from-to)1115-1129
Number of pages15
JournalDevelopmental Psychology
Issue number6
Publication statusPublished - 1 Jun 2017

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  • Genetic architecture
  • Language
  • Reading comprehension
  • Reading fluency
  • Twin study
  • Vocabulary
  • Age Factors
  • Humans
  • Male
  • Statistics as Topic
  • Comprehension/physiology
  • Gene-Environment Interaction
  • Reading
  • Language Tests
  • Speech/physiology
  • Child Language
  • Adolescent
  • Female
  • Child
  • Longitudinal Studies

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