>>17865308 (OP)Keep in mind your own chart says:
Rome CA < Bell Beaker < England BA < Britain N < Britain BA < Rome IA
It's not so straightforward as "EEF were smart". That's reductionist and confused.
The issue with these analyses is that they lack testability in ancient populations. They are more inferential than they are scientific because we cannot give these dead people intelligence tests. Testability is the heart of the scientific method.
I know what you may be thinking though: we can test living people and find genes correlated with intelligence then use those to infer the intelligence of ancient populations. The problem is you are comparing apples to oranges. Ancient populations are not required to have the same genes which promote intelligence in modern populations. It was the same sort of fallacy that led to Cheddar man being called black, but now we've learned he did in fact have pale skin genes, just not ones that are particularly common in most modern populations. Absence of evidence (for intelligence) is not evidence of absence (of intelligence).
Different ethnicities have different genes which promote intelligence, so when polygenic tests are created, you need to understand the population sampled which was used to create the tests that were subsequently used on ancient populations. For example, it's invalid to create tests based on white Americans and then project them onto early European farmers.
But don't GWAS show blacks lack many intelligence genes that Europeans have as expected? Yes, but the key difference here is that we can actually test living black IQs, but black vs European represents a major race distinction (SSA vs West Eurasian) so we could miss intelligence genes specific to blacks by making tests based on West Eurasians. Likewise, EHGs were highly divergent from ANFs. It would be easy to miss their specific intelligence genes because they were genetically unique and not quite like any surviving modern population.