This is such an American problem. I moved from the EU to the US so I have always been pretty strict with work hours. I finish at 17 and don't work on weekends.

I have applied the same approach in the US and I have never had anyone tell me that I have to put in more hours. However, I see a lot of movement over the weekend and at weird times (people working past midnight). But the thing is that no one is really forcing them, I think this way of thinking is embedded within the average American relationship with work.

I have observed this in my wife too. She stays past her contract hours but mostly because a lot of people in her company do the same.

I think this is a "self reinforcing peer pressure problem"