Oh, there's most definitely a "nature" aspect to all this. It's like this, little old Europe all cold and wet sent out people who colonized the entire planet. Sub-Saharan Africa in a broad swath of tropical climate with year round growing seasons and sitting atop enormous mineral wealth is, in contrast, appreciably no different than it was 1000 years ago, once you peel away all the trappings of the foreigners. Why is that? And is it any coincidence that places like Haiti have turned out much the same?
You can find idiots and geniuses in any human population. Where each population's "center of mass" lies is what tells the story. That was the main thrust of The Bell Curve anyway. The thing is, I think anyone with eyes, ears, and a functioning brain stem instinctively knows this to be true, and that is why people like the NRO editors are lashing out. It's all so much conspicuous polishing of their Reasonableness for all to see.