If testing for IQ works for your purposes, then why not use GMAT, GRE, SAT scores?
I’m not sure any of this helps, though, since it would only prove you’re good at the test.
I’m not sure any of this helps, though, since it would only prove you’re good at the test.
I know of some very, very clever people who do not perform well, and the opposite too.
I'm going to guess you're gains plateau or you get to a near-perfect score pretty quickly. The gains you're seeing are just familiarity with the test.