Having just become aware of the existence of the term Delayed Sleep Phase Syndrome (Wikipedia), despite having had "symptoms" nearly all of my life that fit the "diagnosis" (I think you can tell from my scare quotes where I'm going with this) I'm wondering if it is, to put it bluntly, real.
That was my provocative introduction. Here are the facts. I have always felt most comfortable going to sleep late and waking up late. In the times in my life (college, etc.) when I didn't have to wake up early every day, I would generally gravitate toward a late schedule: say, 3:00 am til 11:00 am. This meant unfortunately that the occasional 9:00 obligation was a total nightmare. I tried again and again to wake up earlier, but even if I did I would inevitably drift forward. I just did not get tired at the earlier time like most people do. But once I set into the 3:00 am bedtime, I would get reliably tired at that time, fall asleep, and stay asleep. That's why this is different from insomnia. I could go on and on about my experiences, but I'll spare you. Let's just say I have been annoyed to death over the years by people giving me advice when they clearly just have bodies that are different from mine. The worst is when people imply I am lazy. It's an incredibly frustrating situation because you want to shake them and say "just open your d*mn mind for fifteen minutes and try to understand where I'm coming from." Oh wait, that's also what it's like to be paleo ... I digress.
Now I've read a couple of books on sleep and sleep research, and one thing I learned (in addition to learning that people tend to drift forward in their sleep schedules if they are in sealed apartments without windows or any time cues (Zeitgeber)) was that sleep researchers generally classify people as "owls" and "larks." Some people just have an easier time falling asleep at night or reverting back to an early schedule, and some people are the opposite. So DSPS would just be an extreme version of an "owl" pattern.
After reading that Wikipedia article I was ready to begrudgingly admit that there was something wrong with me, but a passage toward the end caught my eye.
DSPS is a disorder of the body's timing system—the biological clock. Individuals with DSPS might have an unusually long circadian cycle, might have a reduced response to the re-setting effect of daylight on the body clock and/or may respond overly to the delaying effects of evening light and too little to the advancing effect of light earlier in the day. In support of the increased sensitivity to evening light hypothesis, "the percentage of melatonin suppression by a bright light stimulus of 1,000 lux administered 2 hours prior to the melatonin peak has been reported to be greater in 15 DSPS patients than in 15 controls."
Here's my thought. I have a hard time accepting that those of us who are "owls" or even extreme "owls" would be sleeping into the day in a pre-agricultural, pre-industrial setting. So it must be the case that, were the night-time light stimuli not present at all, there would be no DSPS sufferers. But those of us who do fit the pattern are just more sensitive to the stimuli that are nearly inevitably there -- as my block quote suggests. I think a powerful analogy can be drawn to obesity. There were probably no obese paleos. And yet it is not the case that nowadays everyone is obese. The best explanation is that conditions exist which some people are more sensitive to than others. These are the obese.
What do you think? I hesitate to settle on this as a complete explanation -- in part because that is a good policy to follow in general, but also because there are a few peculiarities: one is that the late-sleeping tendency is much more prevalent in adolescents and especially in male adolescents, which could accommodate biological explanation. (I recall recently seeing some publicity on studies showing that we are basically waking up our teenagers way too early for school and making their lives miserable.) Any other theories? Anyone want to share experiences? There is an older paleohacks thread that addresses this, but I wanted to ask about my pet hypothesis, and also this is a important topic to me and I'd be delighted to hear what people have to say. Apologies for the long question. Paul.