When somebody cuts you off in traffic after having woken up from noticeably insufficient sleep, you feel different, right? Worse than you usually would.
New candidates get sent through entire batteries of tests. Personality, aptitude, reasoning… You name it. There is probably a test for that.
When a candidate gets hired, that’s where the tests stop. Why? People change, along with their interests. From one day to the next, you might feel completely different, increasing the need for testing recurrently.
Employees should have the ability to formally restate their professional interests, once in a while.