Genetic and Environmental Influences on Vocabulary and Reading Development.
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.
University of Colorado at Boulder, Linköping University, Sweden.
Richard K
RK
Olson
Janice M
JM
Keenan
Brian
B
Byrne
Stefan
S
Samuelsson
William L
WL
Coventry
Robin
R
Corley
Sally J
SJ
Wadsworth
Erik G
EG
Willcutt
John C
JC
Defries
Bruce F
BF
Pennington
Jacqueline
J
Hulslander