"LeetCode" tests famous on HN are one example.
False.
> but can give work-related skill tests that are extremely similar IQ tests.
Legally, the conditions in which the private sector can give work-related skills tests that are extremely similar to IQ tests are when they fulfill the exact same requirements with regard to those tests that they would need to fill with regard to IQ tests to be able to legally give them; if they are functionally very similar, the circumstances in which they will satisfy those conditions will also be very similar.
The fact that the case establishing the rule on disparate impact discrimination involved (among other hiring practices) the use of IQ testing doesn’t mean that the disparate impact rule applies differently to IQ testing than to other “extremely similar” tests.
Except its not, see, e.g., the Supreme Court decision in Babb v. Wilkie (2020).
> Section 633 of the Age Discrimination in Employment Act of 1967 permits federal employees to sue over any adverse personnel action that is influenced by age, even if age was not the determinating factor.
Sure. But that's the benefit of wearing the crown.
The government also gets to run IQ tests[1] on many prospective employees, which would be illegal in the private sector due to the 4/5ths rule.
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1. https://www.officialasvab.com/