biracial children do better on IQ when the mother is the white parent than when the mother is black
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Actually, there is some evidence that many intelligence genes are carried on the X chromosome.
So, there’s four cases, which I will give names: boy with a black mom and white dad (“Joe”), boy with white mom and black dad (“Rob”), girl with black mom and white dad (“Sal”), and girl with white mom and black dad (“Eve”).
Joe has a black X chromosome and a white Y chromosome.
Rob has a white X chromosome and a black Y chromosome.
Sal and Eve both have one black and one white X chromosome.
If X chromosomes have lots of intelligence-related genes, and if white parents contribute smarter chromosomes than black parents do, then there’s no difference between Sals and Eves (they’ve both got one of each), but Robs should be smarter than Joes on average, because Rob has his g-loaded genes from a white parent and Joe doesn’t.
I’m confused by this prediction. Can you expand out your logic? Assuming these were X-linked wouldn’t the races of the parents be what matters?
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So, there’s four cases, which I will give names: boy with a black mom and white dad (“Joe”), boy with white mom and black dad (“Rob”), girl with black mom and white dad (“Sal”), and girl with white mom and black dad (“Eve”).
Joe has a black X chromosome and a white Y chromosome.
Rob has a white X chromosome and a black Y chromosome.
Sal and Eve both have one black and one white X chromosome.
If X chromosomes have lots of intelligence-related genes, and if white parents contribute smarter chromosomes than black parents do, then there’s no difference between Sals and Eves (they’ve both got one of each), but Robs should be smarter than Joes on average, because Rob has his g-loaded genes from a white parent and Joe doesn’t.
Ah. Ok. That makes sense. Thanks..