It's not a political articleYou were correct in your other comment that I skimmed the article the first time. It set off my BS detector and I didn't bother to painstakingly scrutinizing it to see if it had some other value.
Taking your challenge, I re-read it and now I'm going to go one further. This was a hit-piece article that was designed to go after Murray and satisfy the typical Vox liberal red meat audience. The science that was in the article was incidental and the best they could do given their overall motive of striking at Murray while generating hits from their typical readership.
The title of the article is "Charles Murray is once again peddling junk science about race and IQ"
I think that someone came up with the title of the article first to capitalize on the Middlebury College controversy and then sought to justify that title with as much science as they could muster. Vox knows that they'll get tons of hits just from the title and that the information in the article won't be judged too harshly by their typical readers. My guess is that after coming up with the title, Vox editors got some scientists in the field who are critics of Murray to write up a justification.
Despite the article's title, the scientists admit: "Some well-informed scientists hold views closer to Murray’s than to ours. And there are others who challenge views that we accept about the utility of the general concepts of intelligence and heritability."
So which is it? Is it junk science or do some well-informed scientists agree with Murray more than they agree with the authors of this piece while some other well-informed scientists consider the authors of this piece to have flaws in their basic understanding of concepts that they touch on? My guess is that the scientists wanted this disclaimer in there but that the Vox editor would have preferred to not even make that admission. Those two short sentences in the article completely destroy the title and show that this article was politically (or financially, depending upon how you look at it) motivated.
And it addresses your "twin studies, separated twin studies, adoption studies" dismissal, rather directly.
Well, it agrees with them and even admits: "These “DNA-based” heritability studies don’t tell you much more than the classical twin studies did, but they put to bed many of the lingering suspicions that twin studies were fundamentally flawed in some way."
I wrote more but while trimming it up realized that this nonsense political hit piece has already wasted too much of my time. My BS detector was functioning perfectly the first time and I should have trusted it and avoided going back to that link and contributing to Vox's ad revenue.
edit: typo