Genetic and environmental influences on prereading skills and early reading and spelling development in the United States, Australia, and Scandinavia

Genetic and environmental influences on prereading skills and early reading and spelling development in the United States, Australia, and Scandinavia

Scientific Studies of Reading, June 2006

21132077

Stefan Samuelsson, Richard Olson, Sally Wadsworth, Robin Corley, John C. DeFries, Erik Willcutt, Jacqueline Hulslander, Brian Byrne

Genetic and environmental relations between vocabulary and reading skills were explored longitudinally from preschool through grades 2 and 4. At preschool there were strong shared-environment and weak genetic influences on both vocabulary and print knowledge, but substantial differences in their source. Separation of etiology for vocabulary and reading continued for word recognition and decoding through grade 4, but genetic and environmental correlations between vocabulary and reading comprehension approached unity by grade 4, when vocabulary and word recognition accounted for all of the genetic and shared environment influences on reading comprehension.