its not quite 100%, there is some knowledge of maths involved in IQ tests, I remember when I was taking one when i was a kid there was prime number sequences and that kind of stuff, i dont care if you are a genius if you have no idea what a prime number is you arnt going to figure it out in the time it takes to do an IQ test(i was like 5)

also chinese people do well on IQ tests because IQ tests mainly test mathmatic ability and the chinese number system is just better than the arabic one, it makes maths easier, so it makes IQ tests easier