Truman Capote couldn t say the alphabet and was incompetent at math, Einstein used to get lost on the U of C campus, and so forth. Lacking a little window with a needle indicating intelligence, IQ tests were designed to try to objectify something that s more than that. Smart people can test low, as can intelligent people who are culturally disadvantaged, or who are hardwired with some sort of quirk as I mentioned above.
Some people are poor test takers.
If you re illiterate, forget an IQ test, regardless of how natively smart you might be. Generally, bright people will test high, and while a smart person can test low, a dumb person will never test high. We also have idiot savants, who no one knows what to do with - Rain Men and Women, seemingly the flip side of high functioning people who have a misfiring area. Usually the more emotionally intelligent a person is, the better they ll function with whatever amount of native intelligence they possess, but the concept of EQ has been twisted into an alternative, as if it s all that s needed. In this way, everyone can be a star in today s world in which it seems to be mandated that everyone has to be a winner.