Genetic and environmental mediation of the prediction from preschool language and nonverbal ability to 7-year reading

Abstract

We use a genetically sensitive design to examine the relationship between language and nonverbal ability at 41/2 and reading skills at 7 years of age in a sample of more than 1,000 children participating in the Twins Early Development Study. We find that nonphonological as well as phonological measures of early language make significant contributions towards the prediction of reading at 7, and that nonverbal ability at 41/2 is an equally strong predictor. With respect to aetiology, we find substantial genetic contributions towards the relationship between early language skills and reading at 7, as well as a trend towards shared environmental influences. The genetic continuity is not specific to the verbal domain, however, as we also find a substantial genetic relationship between nonverbal ability at 41/2 and reading at 7. © United Kingdom Literacy Association 2006.