The intelligent discourse is dumb; it cannot say anything universal, which, given we live in the universe now, is a requirement revealed lacking here, there, & everywhere.
No doubt IQ is a measure of something certain, but show me someone who applies it to claim who's not apt to qualify as particularly intelligent and I'll show you a certain kind of idiot.
Of the volks pop figures, who, initialized by science, wander into fields of the pseudo-rific kind by definition of their wandering, making carte blanche inferences from studies not of their make, and emoting empathetic about how, on the contrary, it "breaks their heart" that the so-&-so people are so naturally predisposed to inferior intelligence — if only such an extension of empathy were not so qualified.
Not that there's not reasonable recourse in drawing a line somewhere, still the notion that empathy should have its limits strikes me as selective not in a good way when I hear "I'm sorry, but facts don't care about your feelings."
What of these facts & figures that result of examining who can figure out whatever facts come out of xyz, while ignoring who may or may not care? Not just failing to measure motivation itself but forgoing an honest study of the reasons behind the discrepancy of an abstraction. Regarding the former, "correcting for...whatever" concedes a flaw in the design, the duct tape of statistical research.
Of reliability defined by the fact that every time I've taken the test, thrice I can think of as an adult so far, I scored in the 140s, that's on me.
The long inculcated have been nurtured to the task that led to the test in the first place. Hence the consistency of their respective results. Anyone utterly unfamiliar needs the context before you can say they do or don't understand anything.
Of inconvenient truths that any given someone doesn't want to see, I'd highly recommend, to you who say so, you should be speaking to the you found most reliably in the mirror while calculating your confidence interval in careful consultation with Dunning-Kruger.
And the extrapolation! Nothing says prediction like fudging & nudging: the numbers inside a margin of error & pathetic fallacies into conversations about facts. Leave prophesy to those hellbent on fulfilling them. God's bastards.