Im no neuroscientist or psychologist, but the stress of being sized up by other monkeys based on superficial first impressions that you know you dont happen to be very good at making, is WAY different than the stress that gets produced when a "cryptic" system needs fixing.

For me the former situation leads to lots of bad feelings including irritation and incredible anxiety. I have often considered the latter type of situation fun times. For a lot of programmers difficult puzzle solving stress is good stress.

From what I have witnessed from current in-the-box hiring practices is a lot of extroverts get hired who are good at spin and presentation. Quite a few managers never detect that they are actually not great programmers because they are brilliant at sucking up and putting on a show. Those skills dont always hurt, but they shouldnt be considered a deal breaker for a programmer who actually gets good work done.

Best practice I have ever encountered is when interviewers give out interview questions in advance to allow to the interviewee a while to think about the problem in quiet.

I love the idea of short term contracts for both parties to suss each other out.