[tptacek]

This is a weird pernicious Internet myth. It obviously can't be true, because there's a big, well-known company that delivers these tests for employment/recruiting settings and they have a logo crawl on their page that include several giant companies. If those tests were illegal, employment lawyers would be making bank off it.

[ozb]

I'm not an expert/lawyer, but this does seem to indicate that the situation is a bit more complicated than either "pernicious myth" or "probably illegal" in general (but much closer to toast0's understanding); my interpretation is that you can either avoid an 80% threshold of "disparate impact" or you can in theory formally validate that a particular test measures/predicts performance at a particular job; that all sounds compatible with "companies do it in the open, but very few, and you can easily get in trouble for doing it wrong" https://www.law.cornell.edu/cfr/text/29/1607.15

[tptacek]

The comment to which I responded claimed that IQ tests "probably aren't legal in the US", which is false. They aren't more widely used because they don't work well for candidate selection, but they are used by very large companies that are attractive targets for employment discrimination suits, and wouldn't be if they were legally risky. There are well-known tech companies that up until a few years ago gave IQ tests to candidates!

Empirical observation trumps axiomatic derivation in this case.