Higher IQs are correlated with a long history of urbanization and economic specialization, where higher IQs provide a selective advantage.
There's no arguing this. But, from what I've read about James Watson, he never said anything close to this. Instead, I can even find on his wikipedia page this quote from one of his books:
He writes that "there is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically. Our wanting to reserve equal powers of reason as some universal heritage of humanity will not be enough to make it so"
So it's related to a long history of urbanization and economic specialization? And also Watson's unequal powers of reason? What is he implying if not to say that genetically some people are born without the equal "powers of reason"? He didn't quite say that due to "a long history of urbanization and economic specialization" instead he said due to geographic separation followed by their evolution. Watson's position as a genetic researcher commenting on something that is almost certainly attributed to socioeconomic status is strange, wouldn't you think? Was he commenting on this as an economist or perhaps historian?
I also like how you link to wikipedia pages but not their internal discrepancies on your open and close case that IQ is inherited. Including this quote from your first link:
Eric Turkheimer and colleagues (2003) found that for children of low socioeconomic status heritability of IQ falls almost to zero.
From this source.
You present a perfectly acceptable and fairly logical argument about the advancement of some cultures outpacing others. One need only read "Guns, Germs & Steel" where this sort of thing is discussed in a very sound and well researched way. Do we raise our pitchforks and chase after Jared Diamond with fervor? Not at all. Then again, his arguments didn't rest entirely upon some imaginary gene expression he just hadn't found yet.
Your "political correctness" claim is largely rubbish. While it may appear a knee-jerk reaction, this is the case of people objecting to a statement with no underlying scientific basis while Watson makes claims that we should be able to isolate the "Intelligence Gene." Have we had success in isolating such a gene from the Ashkanazi? Furthermore Watson implies (though never directly says) that lack of similar genes is what keeps Africa repressed -- while making zero reference to the reverberating effects of hundreds of years of European colonizations and their leeching of wealth & resources.