[devposter]

I used to believe I am a night person. Once upon a time I would remain awake until 2 a.m., sometimes until 4 a.m. too, hacking away on some interesting technical problem with no fixed time for when to go to bed. It was impossible for me to wake up before 9 a.m. My professional working hours were between 1:00 PM and 9:00 PM. Since I was working remotely, this scheduled worked fine and led me to believe I am a night person.

About two years ago, I got a non-remote regular job where I need to travel across the city to get to my office. I began waking up early at 6:00 a.m. to reach office early before the traffic begins to peak. My professional working hours are now 6:30 a.m. to 2:30 p.m. My personal hacking hours are 6:00 p.m. to 8:00 p.m. I go to bed by 10:00 p.m. I have become a morning person and I see no difference in productivity.

If I had to choose if one is better than the other, although it would be a difficult choice, I would choose being a morning person is better for the sole reason that I go to bed at a fixed time and I don't keep hacking away at problems indefinitely until 4:00 a.m. when both body and mind are tired.

But at the same time, if my circumstances changed and I had to turn into a night person again, I don't think I would have any difficulty doing that.

I think human beings cannot be categorized into such black and white categories for many things. We are, by nature, adaptable species.

[buttscicles]

That might not be as easy as you expect. Here's a relevant passage from sleep scientist Matthew Walker's book 'Why we sleep' (which I highly recommend):

"Although every human being displays an unyielding twenty-four-hour pattern, the respective peak and trough points are strikingly different from one individual to the next. For some people, their peak of wakefulness arrives early in the day, and their sleepiness trough arrives early at night. These are “morning types,” and make up about 40 percent of the populace. They prefer to wake at or around dawn, are happy to do so, and function optimally at this time of day. Others are “evening types,”and account for approximately 30 percent of the population. They naturally prefer going to bed late and subsequently wake up late the following morning, or even in the afternoon. The remaining 30 percent of people lie somewhere in between morning and evening types, with a slight leaning toward eveningness, like myself. You may colloquially know these two types of people as “morning larks”and “night owls,”respectively. Unlike morning larks, night owls are frequently incapable of falling asleep early at night, no matter how hard they try. It is only in the early-morning hours that owls can drift off. Having not fallen asleep until late, owls of course strongly dislike waking up early. They are unable to function well at this time, one cause of which is that, despite being “awake,”their brain remains in a more sleep-like state throughout the early morning. This is especially true of a region called the prefrontal cortex, which sits above the eyes, and can be thought of as the head office of the brain. The prefrontal cortex controls high-level thought and logical reasoning, and helps keep our emotions in check. When a night owl is forced to wake up too early, their prefrontal cortex remains in a disabled, “offline”state. Like a cold engine after an early-morning start, it takes a long time before it warms up to operating temperature, and before that will not function efficiently. An adult’s owlness or larkness, also known as their chronotype, is strongly determined by genetics."

[stephen_g]

The worst thing about having a very late sleep cycle is that a lot of people with early or in-between cycles often can't fathom the possibility that some other people's sleep cycles can be so different, no matter how hard you try. You get all sorts of things like "you just need to be more disciplined", or "you just need better sleep hygiene" etc... As if I hadn't tried that over the last couple of decades!

If you have these kinds of sleep problems, really that sort of "friendly advice" you get is about as useful as telling a depressed person to "just be happier" or "just stop feeling sorry for yourself." (That is, absolutely useless).

[balfirevic]

> "Although every human being displays an unyielding twenty-four-hour pattern"

Not even this part is true for every single human being.

[SubuSS]

Did your family setup etc also change around this time?

I have an unsubstantiated belief that age / family etc affects this. As you add up more commitments, you start having to work with / for others meaning a lot of overlap time is required. This also means morning is the only time you can get to do your own stuff and eventually the habit sets in.

Anecdotally you can see this in kids who've committed to sports etc. Early. They tend to become morning folk just out of habit even if they party it up for certain years.

[sjg007]

I think it is biological. Babies sleep all day and feed so the parent must attend. Toddlers learn all day nap and go to bed early. Kids can fit a normal routine as well as teenagers but I think that hormonal changes cause teenagers to stay up later and sleep later. In a hunter-gather society this may have been useful for standing guard and raising alarm. Then you have the grandparent/elders who tend to sleep the least. But I also think it is adaptable so as you say people who do sports tend to do so in the mornings. Also if you have a tough work commute you might have off hours to minimize commute time.