It's not even an individual choice nor just "biology." When you have a dorm full of people making noise until 1 or 2 am. When you have all the social activity kicking off at 8 or 9 pm...
Unless your institution has a "quiet dorm" you can get a slot in, and you are sufficiently secure in your own, non-mainstream social status...
Yeah, exactly. It's all well and good for people to rant about Personal Responsibility and those dang coddled snowflakes, but how are you supposed to control everyone around you?
You could always transform your university into a miserable oppressive environment which no one really wants to go to, enforcing early quiet hours in every single dorm...or you could just push the class schedule ahead by a couple hours.
Unless your institution has a "quiet dorm" you can get a slot in, and you are sufficiently secure in your own, non-mainstream social status...
P.S. U.S. perspective.