The test score gap is the problem for which an explanation is sought. The gap in itself is not evidence of anything except for the existence of a gap. There is no evidence that different genetics of different populations is the best explanation.
This is an opinion statement- I don’t believe this is true.
Find the genes (no, I don’t think it’s just one) responsible for high intelligence, determine the relative likelihood of people from different populations having these genes (or whatever fraction of them), and test it by showing a strong correlation between the presence of these genes and intelligence (by an agreed upon measure). Some have suggested eliminating all “nurture” factors, but I can’t think of a way (short of some “biosphere” experiment that I’ve outlined in the GD threads) of doing this.
No, it’s almost certainly not just one gene. My position is just that there is no reason to believe that the test-score gap (or other disparate outcomes) are best explained by different genetics.
No. Disparate outcomes exist- and these threads are generally focused on the gaps in educational (or aptitude) test-scores. I’m not denying they exist. We certainly do not know enough to say that some of the gap is likely caused by heritable factors (for populations). And I don’t believe I’m dismissing any statistically sound studies that point to non-environmental factors. Part of this is because “environmental factors” (or “nurture”) is so broad that it covers every possible factor other than genetics- and generally the only ones that can be statistically eliminated are the easily quantifiable ones- income, parental education, etc. There are plenty that are not easily quantifiable- including the ones that researcher Frank Sweet favors as the best explanation for the gap (he favors a combination of lesser parenting skills, reduced teacher expectations, and an “oppositional culture” peer pressure).
Then you’re trying to solve a different problem. If you have statistical analyses that show that the green ones have more eggs in their nests, then comes the question/problem “Why do the green parrot nests have more eggs?”- but without genetic analysis, any genetic hypothesis has no evidence (because it could be any number of non-genetic reasons).
You keep referring to “statistical data”, but I don’t know of any statistical data that points to a genetic explanation. I have a feeling you’re just referring to lots of statistical data that shows that the gap exists (and that it can’t be wholly explained by things like parental income, parental education, etc)- and while that’s useful if it eliminates other hypotheses, it’s not actually evidence in support of the genetic explanation.
The smoking-cancer comparison is bad on many levels- chiefly because it has nothing to do with genetics (broadly speaking). There is data that shows the inadequacy of certain other hypotheses (like the “income hypothesis” or the “parental education hypothesis”) to explain the test-score gap, but there is no data in support of the genetic explanation. Until there is, there’s no reason to believe it’s the best explanation.