I was once tested by Mensa, for admittance.
They used Ravens Progressive matrices
Raven's Progressive Matrices - Wikipedia
These are supposedly made so as to be blind to social circumstances and schooling.
But as I was computer science, math and philosphy student at the time, I had a lot of training in logic.
And when "guessing", I could use words for the relations between the symbols.
I would think "You and the twirlies, xor the straight lines and or the dots"
I passed the test, and though I am an excellent problem solver in some narrow fields, I am just a big idiot in many more
My one experience with IQ test was not blind to schooling!