Segregation Returns to US Schools

[Montmorency]

Let's say we have X number of ethnic groups where the prevalence of some genetics are above, say, 90%

Sure. The problem for genetic supremacists - of any stripe - is that intelligence is too diffuse*, and whatever genes there may be around that enhance relative cognitive performance would only be subject to random, or incidental, selection in any population defined in social-racial terms.

For example, it is technically possible that:

1. The Black Death did not affect sub-Saharan Africa.
2. The Black Death affected all of Eurasia.
3. Resistance to the Black Death somehow happened to coincide with intelligence-boosting genes in Eurasians.
4. The Black Death killed the stupider half of Eurasia and left only the more intelligent to breed with one another.
5. Average intelligence in Eurasia increased.

Of course, just because something is possible doesn't mean that it has happened, so any way you look at it the genetic supremacists have an uphill struggle when it comes to assembling evidence that there are regular genetic differences between any grouping (to say nothing of evolutionary explanations for them), again recalling the arbitrariness of racial groupings.

Also keep in mind that a scenario such as the one I made up above ignores the massive ethnic variation within sub-Saharan Africa, meaning that those who entertain such possibilities must also own that its technically possible for the most intelligent group of humans (by virtue of genetics) to be a group of sub-Saharan Africans. I see no coherent reason a priori why this could not be the case, if we are taking a proper agnostic approach to the issue.

*i.e. intelligence is clearly not "additive", though it is modular and subject to developmental baseline and differential expression under variable environmental conditions

[Viking]

Of course, just because something is possible doesn't mean that it has happened, so any way you look at it the genetic supremacists have an uphill struggle when it comes to assembling evidence that there are regular genetic differences between any grouping (to say nothing of evolutionary explanations for them), again recalling the arbitrariness of racial groupings.

The possibility of such a thing happening as well as how it could happen is what I originally replied to. If it actually has happened is indeed a separate topic.

*i.e. intelligence is clearly not "additive", though it is modular and subject to developmental baseline and differential expression under variable environmental conditions

I don't see any incompatibility between modularity and additivity. Not sure what your point is.

[Montmorency]

I don't see any incompatibility between modularity and additivity. Not sure what your point is.

Well, first note that you're not the only person included in the discourse, so I shouldn't be considered as addressing these solely to you.

In principle there is no incompatibility between modularity and additivity, but we have observed that additivity in itself can't really be associated with intelligence.

Think about it: what exactly would that look like, both behaviorally and epistemologically, if intelligence could be 'added up like a sum'. It recalls to mind the cartoon image of a person with an opened cranium having brains scooped into his skull so that he could become "more smarter".

This isn't to say that intelligence is fixed within or between individuals, that it can't change or increase, just that with regards to the present context we should not approach this from the assumption that the base is "zero" intelligence and genes 1-10 can each "add" some amount of intelligence for a 'natural' maximum where all the genes are present.