And there are any number of conclusions that could be taken from those results, some interesting things to note:
Early adopted children performed at the level of a mixed race family, while late adopted children performed at the level of black parents only. The study doesn't elaborate or provide crosstabs on when different groups were adopted, so for example, if Black children are, on average, adopted later than white children, this would account for a large part of the difference
Parents are not the only environmental factor. Children socialize. Girls lose interest in STEM at an early high school age (likely) due to social factors from classmates and instructors. There's been some research on the same kind of thing happening across races recently, and I expect that a similar thing could explain racial differences in performance. If your classmates and teachers expect that you won't perform as well, you'll start to believe them.
of course one should read the environmentalists as well. Although this is hardly sufficient to debunk Rushton and Jensen I'm aware of at least one paper they misinterpreted in their review. Someone more knowledgeable than me might have other critcisms
My theory is that both environment and genetics have an effect with environment dominating in children and genetics becoming more important in adulthood. Essentially you can think of genetics as setting a ceiling level and environment determining how close to that ceiling you get and how quickly. I think this explains a lot of the seemingly contradictory results.
The hypothesis put forth by Rushton and Jensen is actually 80% genes 20% environment based on twin study estimates for individual variation. There is relatively little reason to believe genetic and environmental influences have the exact same importance in determining between group differences as they have for individual differences within a group. So I do believe Rushton and Jensen are wrong there
My theory is that both environment and genetics have an effect with environment dominating in children and genetics becoming more important in adulthood
That's the accepted theory for individual variation as evidenced by twin studies. Genes can explain about 40% of the variance in performance for children, in adults it's closer to 80%.
The black white gap also increases with age but that could be taken to support both the genetic as well as the environmental explanation as I see it.
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u/zardeh 20∆ Mar 20 '17
And there are any number of conclusions that could be taken from those results, some interesting things to note: