Um, I asked Grok and aren't IQ tests soft-outlawed under disparate impact? As opposed to skill qualifications, it's hard to prove that, say, you need to be "intelligent" to work at a certain job. You would end up having to argue that intelligence even exists in court, which I can see why companies would try to avoid- ie. disparate impact creates a reversed weight of evidence. If your test has disparate impact, you now have to prove that it's necessary, creating a chicken-and-egg problem.
Nope. It's trivially easy to pull up (a small minority of) Fortune 500 companies that use IQ tests in their hiring processes. The companies that offer these tests brag about the companies that use them. Whatever Grok thinks about this doesn't really much matter in the face of that evidence.
I think they use "aptitude tests" or "personality tests" that are at least packaged up to look relevant to the job, not direct naked IQ tests? I can't offhand find companies using actual IQ tests in hiring.
And if you're saying "well those are just repackaged IQ tests, so doesn't it count", then 1. it sure seems like IQ tests are illegal then, but 2. it also seems like they're so useful that companies are trying to smuggle them in anyway?
No, they use general cognitive tests, advertised as such. I don't think there's a way to wiggle out of this: IQ testing in hiring is fully lawful and accepted in US employment law.