[sidlls]

> Any studies that support the answer "no" for both questions?

Google had a study that has been linked to death around here which showed the scores hires received on their interviews didn't correlate to job performance ratings. There are of course biases and flaws in that study, but it underscores another separate point: studies should show they do correlate, not the other way around (prove a negative).

> Finally, "and companies use them in spite of that". Any guesses why?

Bandwagon effect, cargo cults, ego boosting/confirmation bias from applying a hazing ritual, laziness all come to mind.