There has been plenty of controversy over the meaning of IQ tests in the first place. One complaint is that they test cultural knowledge more than intelligence

There has been plenty of controversy over the meaning of IQ tests in the first place. One complaint is that they test cultural knowledge more than intelligence itself. Naturally, there will be some correlation between the two, but my point is that a great deal of what IQ tests test may be learned knowledge. While your ability to learn that knowledge may be related to intelligence, it does not follow that all intelligent people will score highly on a particular IQ test. Intelligence may be heritable even if IQ test performance is not.