5 days
I hope someone with expertise will provide a better answer, but since there’s none yet I’ll give my intuition.
It’s a signal. It tells whoever you’re interacting with that you’re doing stuff in your head, so they know you’re listening, that you’re thinking of an answer or something like that.
Imagine how weird it’d be if we didn’t do that. You say something to a person and they just stare at you without moving a muscle for a few seconds before reacting. You’d think there’s something wrong with them
He thought he could fool us with that username