Interesting but very touchy stuff. It reminds me of this argument against human cloning that says, ignore all other arguments, just look at the types who are interested in this to understand it should not be allowed. The pages you link to include little-argued statements like "The arrow of cause points mostly from IQ to income, and not the other way round." or this jewel from Steve Sailer, who first writes "it is hard to avoid concluding that intellectual and income differences between nations stem to some extent from genetic differences. The results simply cluster too much by race" and then imparts the following wisdom on us "But it could also be that freedom exercises the brain - West Germans averaged 103 while East Germans scored only 95. My pet theory is that having to make all the choices between products available in a successful capitalist economy stimulates mental development. (I believe this because, as I get older and stupider, I increasingly find shopping to be intellectually exhausting.)" Not convinced here. Yes, I am aware that you personally advocate caution in your post.