The things I think the standard IQ test measures are more about a combination of an ability to quickly visually process information, and some elements of mathematics/logical thinking. I’ve scored +1.3~2.0 z score at various points in my life, and I think that the elements are that I can read extremely quickly and perceive math problems very quickly.

I’ve frequently worked with students who understand math and patterns very well, they just struggle with some element of the visual processing. They transpose numbers and letters when they see them, they switch up letters in geometrical figures, they get so overwhelmed with the stress of reading under eye or the clock that the words mix up and they miss the meaning.

They have the low “IQ” has measured. But they are capable of understanding the concepts - just not conveying them in the way that a standardized instrument can (or even should?) measure.

Ie; I don’t think it’s that great a measure beyond the sub 80 - which is a meaningful deficit and is acknowledged in the process of diagnosing for developmental delays/impairment. (It also can entirely be overcome in some cases with good support - like istfg as someone who has been paid to do this kind of thing the difference is that poor/middle class kids don’t get help)