Is there any scientific reason put forth as to why people between the ages of, say, 13-20 like to go to bed really late and wake up really late, whereas old people are the opposite? Is it social conditioning, like the stuff teenagers are into tends to be more available/open at night and vice versa for the old? Or do circadian rhythms change w/ age?
There have been a lot of studies that show that teenagers perform best in school if they are allowed to go to bed later and get up later (due to teens typically having later in the evening melatonin production than adults), which is why a lot of schools have contemplated starting a high school day ten o’clock.
I think you are generalizing about older folks. I don’t know what proportion of them go to bed early and get up late but many I know do the opposite including me and my wife.
I am 81 and go to sleep about 10PM and usually get up about 7AM. Works for me.
I think it’s a lot about habituation.
My dad got up every day around 4:30 for work, for about 30 years. The man can barely sleep past 7:30. “Sleeping in” to him, is like sleeping until about 8. I always thought he was nuts.
My first few years after college, I took shift work and worked weird shifts. I loved 2nd shift, because my natural circadian rhythm seems to be: in bed around 2 a.m., up around 11 a.m. Working from 3-11 just suits me.Then I got on first shift and then moved to an office gig, regular old 9-5. It took me forever to be able to get up at say 7 to get to work on time. Weekends I will slip right back to my natural pattern and have to over-exhaust myself on Sundays so I can get enough sleep.
At this point, I am habituated to wake up around 7 a.m., with or without an alarm clock. I also have a four-legged alarm clock who knows what time he should be fed (cat). Given a two week vacation, or a four day weekend, I will revert back to “2nd shift” hours.
My mom, OTOH, who is 66, has worked 2nd shift for the last 25 years or so. The woman can barely get up before noon if she HAS to and rarely goes to bed before 2 a.m. She told me since she’s retired, she now goes to bed at 4 or 5 in the morning and gets up at 3 or 4 in the afternoon. Yes, that’s like 11 or 12 hours of sleep. Counters the notion that seniors require less sleep as they get older.
I’m a second shifter as well (only 26, but obviously well out of my high school years). I go to bed around 5 am and wake up at 1pm, to be at work at 230, 5 days a week. Over 2 years with this schedule and I very rarely deviate from it (exceptions being when I need to travel or for a holiday). It helps that I generally had later classes my last couple of years of college, so I’ve been used to this sleep schedule for years now.
I also had only a little difficulty adjusting to graveyard shifts as a computer tech in college, it wasn’t too bad to go to bed at 9am and get up at 5pm. However, anything that forces me out of bed before noon on a typical day… man, I don’t know. I could do it for the right amount of money or if I absolutely had to–preferable to being unemployed–but I’d have to turn into one of those caffeine maniacs who needs half a pot of coffee just to function in the morning.
I seriously just don’t do mornings–I never have. I’ve been a night owl since I was 14. On the weekends, I used to spend all night reading a book under my covers, then wake up at noon (provided my mother didn’t try to rouse me before I woke up naturally). It’s just the pattern with which my body is most comfortable. I did exceptionally well in high school despite the sleep deprivation, so it can be overcome. But it’s not easy and I don’t know if I could do it forever. There is just something about the morning sun that I don’t like. It makes me sneeze >:[
I know my (almost 14 YO) son would love this idea (Well, he’d probably say it’s still too early, but, y’know…) His sisters can snore up a storm until noon, given half a chance, as well (although not quite as markedly)
OTOH, it’s not just teens – they’ve all come by this trait honestly (i.e., they’ve inherited it from Daddy :o); I sorta, kinda manage to get up at 7 every morning, but I do a lot of “get out of bed at 2:30, walk around the house a bit, raid the fridge and wonder why I can’t lose weight, finally go back to sleep”, and left to my own devices I slip easily into a 3-11 am sleep schedule or even further off-kilter.
In other words, I’m rachelellogram 20 years later… 
(I’m 47.)
It’s great for inter-continental traveling, though. Jet lag? What’s jet lag? 