[throwaway936482]

Depends on the test. There's been a move away from tests that require cultural or language specific knowledge and which instead rely on "which shape in the sequence comes next" type questions but they have their own set of problems in that they don't capture linguistic ability which is a part of intelligence, and are also useless for blind people. Earlier IQ tests required a lot of culturally specific knowledge, and were often quite up front about it because they considered the possession of such knowledge to be a marker of intelligence. Generally that viewpoint is out of fashion now so test makers try to come up with tests that measure "pure" Intelligence, whatever that means.

[LudwigNagasena]

Culturally specific knowledge obviously correlates with an ability to learn by the very definition of the ability to learn.

I doubt this viewpoint is out of fashion. The problem is that it is hard to compare people from different environments if you use knowledge that depends on the environment...

[stonecharioteer]

So does this mean Einstein's IQ was subjective? Was he supposedly smart because he had encountered things on the test before? Would he score lower on one today?