“I could see it going either way” is consistent with having a best estimate that goes one way rather than another.
Just as you have the Flynn effect with intelligence, so average height has also been increasing. Would you say the same thing about height, that the average height of white people and black people has no significant genetic difference, but it is basically all cultural? If not, what is the difference?
In any case, both height and intelligence are subject to sexual selection, not merely ordinary natural selection. And where you have sexual selection, one would indeed expect to find substantial differences between diverse populations: for example, it would not be at all surprising to find significantly different peacock tails among peacock populations that were separated for thousands of years. You will find these significant differences because there are so many other factors affecting sexual preference; to the degree that you have a sexual preference for smarter people, you are neglecting taller people (unless these are 100% correlated, which they are not), and to the degree that you have a sexual preference for taller people, you are neglecting smarter people. So one just-so-story would be that black people preferred taller people more (note the basketball players) and so preferred more intelligent people less. This just-so-story would be supported even more by the fact that the Japanese are even shorter, and still more intelligent.
Granted, that remains a just-so-story. But yes, I would expect “ex ante” to find significant genetic differences between races in intelligence, along with other factors like height.
“I could see it going either way” is consistent with having a best estimate that goes one way rather than another.
Just as you have the Flynn effect with intelligence, so average height has also been increasing. Would you say the same thing about height, that the average height of white people and black people has no significant genetic difference, but it is basically all cultural? If not, what is the difference?
In any case, both height and intelligence are subject to sexual selection, not merely ordinary natural selection. And where you have sexual selection, one would indeed expect to find substantial differences between diverse populations: for example, it would not be at all surprising to find significantly different peacock tails among peacock populations that were separated for thousands of years. You will find these significant differences because there are so many other factors affecting sexual preference; to the degree that you have a sexual preference for smarter people, you are neglecting taller people (unless these are 100% correlated, which they are not), and to the degree that you have a sexual preference for taller people, you are neglecting smarter people. So one just-so-story would be that black people preferred taller people more (note the basketball players) and so preferred more intelligent people less. This just-so-story would be supported even more by the fact that the Japanese are even shorter, and still more intelligent.
Granted, that remains a just-so-story. But yes, I would expect “ex ante” to find significant genetic differences between races in intelligence, along with other factors like height.