I agree with this. I don't believe anybody has a 'natural' cycle. I think it's all a function of habit. You can train your body to get used to whatever cycle you desire or need (ie. To get to work on time).
I've gone through night owl phases in the past, but I always felt like it was by choice, and I had the luxury of no desk job. I guess it felt fun or something. I've also gone to bed at 9 every night when I worked at a golf course & had to be there @ 6am. When I was in a rythm, I would wake up on time every morning with no alarm. And for months after I got a different job I would still wake up at 5am even though my alarm was set for later.
So I would agree with the idea that if you rely on the alarm your doing it wrong. If you practice a consistent bed time, and get your full requirement of sleep, you will wake up naturally just from good habits, be it early or late.
Our bodies are very pliable, and can be influenced one way or another with consistent practice.
Your opinion is fine, but almost certainly wrong. Everyone has a natural cycle. I think the problem is that we have so many problems with our sleep that are even greater than the impacts of the differences between one cycle or another.
I just think our bodies are able to adjust to the inputs we give it. It's difficult, no doubt, to shift the schedule our body gets used to sleeping on. But with discipline, I think anyone can shift the schedule from early to late or vice versa.
If you're saying we all have a natural 'early' or 'late' cycle, how would that even work biologically? What would determine that? Is it hardwired into the code of our DNA? Even if this is the case, you would be handed a certain natural 'cycle' from your parents. But we know that gene expression is not static. We know many gene expressions change fluidly throughout our life depending on our environment/ behavior.
So even if I was born with a proclivity to stay up late, I would still expect to be able to change that though concerted effort and practice.
I'm also probably a little conceited when it comes to sleep habits :) I feel lucky to not have any trouble falling and staying asleep.
I definitely have sympathy for people with sleep problems/ disorders. When I was in my early teens, I had horrible troubles going to sleep. I would lay in bed, sometimes hours, without being able to fall asleep. I grew out of it for whatever reason as I got older. This is interesting now that I think of it, considering the wikipedia someone posted below on chronotype, suggesting adolescents tend to prefer delayed sleep.
But the reasons adults or children have trouble with sleep are complex and difficult to identify I'm sure. I don't envy anyone with sleep problems.
Chronotype does have a significant heritable component. Studies have even identified specific markers near genes known to affect circadian rhythm.
Most people can shift their schedule up to an hour without too much trouble. They can also force themselves onto almost any schedule with strict habits and/or medication. That doesn't mean they adapt. One illness can wipe out months of routine.
Sleeping later is easier than sleeping earlier for most people. Bright light delays your sleep cycle.
Intuitively, it makes sense that people would have different sleep cycles. A pack of animals is more likely to survive if one is awake or sleeping lightly.
That's interesting. To be fair, I've for sure been speaking from intuition alone. I'm interested to look more into the real science of it. I'm sure there is a default mode we are prone to just based on being human. My main point is that it is that our chronotype is pliable. We can shape it and mold it it we want to.
The article is suggesting there is a natural progression correlated with age, that shifts from advanced -> delayed -> back to advanced. This does not help convince me against my hypothesis that cronotype is fluid and not static.
Intuition can be valuable, but I think we should distinguish opinions from facts. This is something that affects people's health, jobs, and relationships.
Chronotype, sleep phase, and when people actually sleep are related but not the same.
The Wikipedia article and my other comments go into more detail about the research. I singled out delayed sleep phase in adolescence because it's been observed even in other species. It seems counterintuitive that this would be so consistent if there were no reason for it.
Sleep phase shifting with age doesn't make it infinitely pliable. You can influence libido, but the difference between 16 and 60 is mostly biological.
I've gone through night owl phases in the past, but I always felt like it was by choice, and I had the luxury of no desk job. I guess it felt fun or something. I've also gone to bed at 9 every night when I worked at a golf course & had to be there @ 6am. When I was in a rythm, I would wake up on time every morning with no alarm. And for months after I got a different job I would still wake up at 5am even though my alarm was set for later.
So I would agree with the idea that if you rely on the alarm your doing it wrong. If you practice a consistent bed time, and get your full requirement of sleep, you will wake up naturally just from good habits, be it early or late.
Our bodies are very pliable, and can be influenced one way or another with consistent practice.