Night people tend to go to bed when they're tired and wake up when they're done sleeping.
Early risers either use an alarm or go to bed / wake up at fixed (i.e. forced) times, mostly due to external constraints.
Is the difference really between scheduled sleep and sleeping when you feel like it?
Having to get up at a time that doesn't suit you due to external constraints is something that can affect anyone.
It's just that early risers get tired earlier (and fast) and then often wake up quickly, fully awake. My brother has always been like this.
I'm a night owl. I get tired more slowly, go to bed later, and take a while to fully wake up too.
It seems to me there is a difference in metabolism as well as the time we get tired. Early birds are like sprinters, fast but short distance. Night owls are more like marathon runners, not so fast but keep going longer. I don't have scientific evidence for this, it's simply how it appears to me.
When I was choosing a secondary school for my son, there was one that pushed "being early" as some kind of moral crusade. Despite evidence that teenagers don't actually work well with that. We did not apply to that school.
Nope.I end up waking up early when I like it or not. so I force myself to go to bed early as i like sleeping. Shame I am not very goo at it.
But I really hope the article isn't measuring people who wake up forcefully.
One point in favor of this theory is that even I, a night owl, manage sometimes to wake up before the alarm on the rare days that I do need to wake up early on.
I've long assumed it's probably due to people who'd do bad things with any sort of useful, "I'd like to go to sleep in the next 15 min, oh and no side effects if the fire alarm goes off in 30 min" kinds of drugs that they aren't a common OTC item.
I had to do it for several years.
I felt like absolute shit every morning. I felt sick and couldn't eat before 10.
Every Day.
I don't have that now I can get up later.
I can rise early without an alarm just by sleeping early.
The stupid article doesn't link the actual paper and I'm lazy to search for it but I wouldn't be surprised if this is a correlation-not-causation situation, since a lot of unskilled work does in fact require rising early while a lot of intellectual work has flexible hours.
except i need to be a certain level of tiredness before falling asleep (i think my adhd affects this - according to all the stuff i read)
but with a little training, i can be a early riser or a night owl - although it's pita to transistion