I have to give credit to Eric Raymond for grabbing the third rail and writing a very interesting and politically incorrect piece about IQ.
And the part that, if you are a decent human being and not a racist bigot, you have been dreading: American blacks average a standard deviation lower in IQ than American whites at about 85. And it gets worse: the average IQ of African blacks is lower still, not far above what is considered the threshold of mental retardation in the U.S. And yes, it's genetic; g seems to be about 85% heritable, and recent studies of effects like regression towards the mean suggest strongly that most of the heritability is DNA rather than nurturance effects.
We need to face this issue and research it, not sweep it under a rug. I don't agree with IQ and success, however -- the smartest guys I knew in college (mostly men) have been left behind by their still-bright but ambitious and socially skilled counterparts (frequently women). Its pretty infrequent to meet someone extremely successful and super smart -- once you cross a certain threshold, its drive and vision that brings a person to the top.
In summary, I don't know what to think. But well worth a read. Motto: Always read the blogs you disagree with first -- otherwise you're wasting posts.