Interesting article in the Journal of Child Psychology and Psychiatry that Highered Intelligence discovered last month. I'll just quote the conclusion:
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.
Hmm. No sample sizes are provided, which is odd, so I can't say much about the generalizability of the study. I'd also like to know the size of the significant correlations - some effects are significant yet not meaningful. I'd also like to know a lot more about how a child becomes involved in the Colorado Adoption Project - are we talking about only middle-class adoptees here? Is there a balance of race and sex across the adopted children? Do adoptive parents read to their children more or less than biological parents? Without reading the full paper, it's hard to know how much weight to give their conclusion, which is that a lot of reading capability is genetically influenced, and that the environmental effects on reading ability may not be related to environmental parental effect.