Parent-offspring resemblance for reading performance at 7, 12 and 16 years of age in the Colorado Adoption Project

Background: The study aimed to conduct the first analysis of CAP parent-offspring resemblance for reading performance in children aged 7, 12 and 16 years, and to assess the etiology of individual differences in reading performance of children at 16 years of age. Method: The Reading Recognition subtest of the Peabody Individual Achievement Test was administered to children in the Colorado Adoption Project (CAP) at 7, 12 and 16 years of age, and to their adoptive and nonadoptive parents when the children were 7 years of age. Results: Resulting parent-offspring correlations in adoptive families were not significant at any age, but correlations between scores of nonadoptive control parents and their offspring were significant at all three ages. Conclusions: Results obtained from behavioral genetic model-fitting analyses of data from parents and their children tested at age 16 are consistent with results of studies of twins and siblings indicating that individual differences in reading performance are due substantially to genetic influences. In contrast, environmental transmission from parents to offspring was negligible, suggesting that environmental influences on individual differences in the reading performance of children are largely independent of parental reading performance.