[lkjhdcba]

Genetics happens to be my field and...yeah. IQ is just too far removed from an actual mechanistic explanation ("gene X does this which interacts which gene Y whose coding protein triggers a cascade onto receptor Z of the brain which...") and for a geneticist if you haven't got a mechanism you've got nothing. There are far more interesting, solid and construct-valid traits to study.

As for neurosci I'll admit it's second-hand knowledge from my social circle and colleagues, though it could be that I live in a bubble and neuroscientists are secretly terrorized to share their mindbreaking findings on the first component of a PCA.

>if nothing else, it measures your ability to take IQ tests, and IQ score has some correlation to “success” in western culture (note i’m not saying “intelligence” anywhere here).

This is circular, since many of the required tests to be "successful" are similar to IQ tests or "g-loaded" as people like to say. Even then, the correlation is weak beyond very low IQs.