Reading and Writing

, Volume 20, Issue 1, pp 77–102

Longitudinal twin study of early literacy development: Preschool through Grade 1

  • Brian Byrne
  • Stefan Samuelsson
  • Sally Wadsworth
  • Jacqueline Hulslander
  • Robin Corley
  • John C. DeFries
  • Peter Quain
  • Erik G. Willcutt
  • Richard K. Olson
Article

DOI: 10.1007/s11145-006-9019-9

Cite this article as:
Byrne, B., Samuelsson, S., Wadsworth, S. et al. Read Writ (2007) 20: 77. doi:10.1007/s11145-006-9019-9

Abstract

Grade 1 literacy skills of twin children in Australia (New South Wales) and the United States (Colorado) were explored in a genetically sensitive design (N = 319 pairs). Analyses indicated strong genetic influence on word and nonword identification, reading comprehension, and spelling. Rapid naming showed more modest, though reliable, genetic influence. Phonological awareness was subject to high nonshared environment and no reliable genetic effects, and individual measures of memory and learning were also less affected by genes than nonshared environment. Multivariate analyses showed that the same genes affected word identification, reading comprehension, and spelling. Country comparisons indicated that the patterns of genetic influence on reading and spelling in Grade 1 were similar, though for the U.S. but not the Australian children new genes came on stream in the move from kindergarten to Grade 1. We suggest that this is because the more intensive kindergarten literacy curriculum in New South Wales compared with Colorado, consistent with the mean differences between the two countries, means that more of the genes are “online” sooner in Australia because of accelerated overall reading development.

Key words

EnvironmentGeneticsPhonological decodingReading comprehensionSpellingWord identification

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Brian Byrne
    • 1
    • 5
  • Stefan Samuelsson
    • 2
    • 3
  • Sally Wadsworth
    • 4
  • Jacqueline Hulslander
    • 5
  • Robin Corley
    • 4
  • John C. DeFries
    • 4
  • Peter Quain
    • 6
  • Erik G. Willcutt
    • 5
  • Richard K. Olson
    • 5
  1. 1.School of Psychology and Language and Cognition Research CentreUniversity of New EnglandArmidaleAustralia
  2. 2.Department of EducationStavanger UniversityStavangerNorway
  3. 3.Department of Behavioral SciencesLinköping UniversityLinköpingSweden
  4. 4.Institute for Behavioral GeneticsUniversity of ColoradoBoulderUSA
  5. 5.Department of PsychologyUniversity of ColoradoBoulderUSA
  6. 6.School of PsychologyUniversity of New EnglandArmidaleAustralia