Various studies have reported genetic effects on attention problems assessed at different ages. However, there has been less research on the developmental course of genetic effects on attention problems. Using data from the Netherlands Twin Registry, Rietveld et al. (2004) analyzed preschool CBCL scores obtained at age 3 and school age CBCL scores obtained at ages 7, 10, and 12 years. Because data were available for different birth cohorts at the different ages, sample sizes ranged from 3,124 at age 12 to 11,938 at age 3.
However, 2,192 children had complete CBCL data for ages 3, 7, 10, and 12. Structural equation modeling (SEM) indicated heritabilities of nearly 75% at each age for both genders. High correlations between scores from early ages to later ages were attributable mainly to genetic effects, especially from age 7 to age 12. The authors concluded that attention problems are highly heritable at all the ages studied, that the same genes are evidently expressed in both genders, and that the relative sizes of the genetic and environmental contributions remain consistent across the ages studied.
Reference: Rietveld, M.J.H., Hudziak, J.J., Bartels, M., van Beijsterveldt, C.E.M, & Boomsma, D.I. (2004). Heritability of attention problems in children: Longitudinal results form a study of twins, age 3 to 12. Journal of Child Psychology and Psychiatry, 45, 577-588.