@SaphireNY The SAT started out life as exactly that - an IQ test, and it still correlates very highly with IQ. Moreover, you seem to be mixing the ACT and the SAT. They are not the same thing. The same person taking the test multiple times can expect to get different scores. It will not be exactly the same each time. Are you aware that students “study” for the SAT and actually see their scores go down?
“Graduate entrance exams”? Are you referring to the Graduate Record Exam?