I would expect that enslaving a particular group would have an effect on how their genes get mixed up over time compared to a control group of non-slaves.
It's not a mistake to tie it to race. Race, or some hidden variable correlated to it, is highly predictive even after accounting for income and similar things.
Further, the effect size is large - far larger than anything you could hope to accomplish with a teacher.
Supposing that the cause is genetic, I'm not sure how it's different if the genetic influences were caused by slavery or something prior to it. Either way, the net result is that an identifiable group of humans will have an intelligence distribution shifted to the left.
Note that my claim had nothing to do with genetics - the genetic influences are trickier to pin down than the racial differences. Also, there is significant evidence that at least part of the black/asian gap is caused by factors other than racism and genetics - namely the overperformance (relative to black Americans) of black immigrants.
> Race, or some hidden variable correlated to it, is highly predictive even after accounting for income and similar things.
Since you're convinced of this position, please provide a biological definition of each "race" you think shows this effect, and we'll see if the data actually agrees with your claims.
Everything I said is perfectly valid if you take a sociological definition of race, so demanding I provide a biological definition of one is silly. The data I cite is based entirely on self-report - to the Census, to the California Dept of Education, and similar government bodies.
You'd know this if you actually read the sources I cited.
So yes, you are right. The study was not based on a biological measurement. We cannot rule out the possibility tyat at every income level stupid people with pale faces are more likely to self-identify as black while smart people with dusky skin are more likely to self-identify as white.
I would expect that enslaving a particular group would have an effect on how their genes get mixed up over time compared to a control group of non-slaves.