I'm not in the US, and the work culture is a lot different here.
Culturally, native corporate workers and the shitholers are afraid to leave before the boss does. And if the boss hates his family and/or is a workaholic, you're shit outta luck. The company mouths the government's party line about "work-life balance," but the deciding factor for who gets promotions/raises always seems to be, "he left early that one time..."
On the other hand, the honkies hold up a copy of their contract, say, "It says here my hours are x to y," and walk out at the designated time. We aren't getting promoted anyway. Newbs will try to hang out late to fit in (I did), but it is fucking boring--you have nothing to do, the boss is clearly just reading a magazine, and you quickly get tired of it.
You might get "lucky" if the boss wants to go out to eat or have a drinking party. It's better than sitting in the office, and he's buying, but once again, you'd rather be someplace else. I sometimes go to the pre-announced ones, which always draws backhanded comments ("not to busy for us tonight, eh?").