I see some basic flaws in the sleep-exercise and sleep-food analogies.
There are reasonably well-understood physiological mechanisms showing how slight overuse of muscles starts a process of strengthening those muscles. I did not see any proposed mechanism for less sleep reducing your need for sleep. (If I missed it, please let me know). While it is true of lots of inputs (food, oxygen) I do not think it is defensible to arbitrarily generalize the idea that reduction of any input allows you to function with less of that input.
With the food analogy specifically, there is a much different element of control. I can sit in front of a delicious meal at any time and abstain, even if my body is “telling” me I am starving, or I can eat garbage if my body is “telling me” I am not hungry. I can’t do that with sleep without chemical help, except perhaps delay sleeping for a few hours or sleep a few hours late. My conclusion is that I sleep when my body needs sleep. If I go to bed and 9 hours later wake up naturally, I needed the 9 hours.
Of course, if I wake up and have nothing to do, and decide to stay in bed for another hour, that does not mean my body needed 10 hours. But the 9 hours I had no conscious control over? Yup, my body did what it needed to do.
My conclusion is that I sleep when my body needs sleep. If I go to bed and 9 hours later wake up naturally, I needed the 9 hours.
I think the right conclusion is that you sleep when your body compels sleep, and that your body has a greater ability to compel sleep than it has to compel eating. You have identified your body’s needs with its ability to compel your acquiescence.
This is plausible: we might expect that evolution would equip us with urges in proportion to their importance for survival and reproduction. But we also know that we’re subject to a wide array of dysfunctional compulsions, including drugs, gambling, and anger management problems.
Furthermore, some strong urges serve purposes that aren’t apparent. If you spontaneously start to vomit because of something you ate 6-24 hours earlier, you won’t immediately know which food item triggered the vomiting. Moreover, the vomiting itself is not “what your body needs.” Intead, it’s the clearance of the toxin. A person with a chronic vomiting problem, or let’s say migraine headaches, doesn’t tend to interpret the strong urges to puke or avoid light as “what their body needs,” but as a symptom of a health disorder.
This isn’t to say that the need to sleep is the symptom of a health disorder. Instead, it’s to say that we have a pretty hazy notion of where to put the dividing line between urges and needs, or healthy/enjoyable/excessive/dysfunctional sleep. At least one book has been written seriously arguing for responsible heroin use.
As far as I’m concerned, you can put the dividing line for your own sleep wherever it seems right to you. But if we’re talking about the scientific study of sleep, as Guzey and Matthew Walker are, it’s no longer epistemically permissible to base that decision on one’s personal opinion.
Why might we care to go beyond personal opinion? Consider the analogy of scurvy. A sailor with scurvy doesn’t feel any strong urge to eat Vitamin C pills or suck on a lemon. But it’s a very particular vitamin deficiency they’re experiencing, and it’s the careful study of why lemons and liver prevent and cure scurvy that allows us to get to the heart of the matter. In the time in between the realization that citrus was associated with scurvy prevention, there were a lot of misapplied interventions. It was assumed that the sourness was responsible for scurvy prevention, so sailors were given ineffective limes rather than effective lemons. The juice was piped through copper tubing that destroyed the vitamin and the benefit. The knowledge itself was gained and lost by the naval authorities of the time, even as changes in sailing times decreased scurvy incidence for reasons unrelated to sailor diet.
I for one am happy to know that vitamin C cures scurvy, even though I happen to live in a dietary environment that reliably supplies me with an adequate dose without me needing to ever think about it. I happen to know that folic acid is not routinely added to the maize used by Latino Americans, and for this reason, that community suffers elevated rates of entirely preventable neural tube birth defects. I very much wish that we’d start putting folic acid in maize. But it’s our knowledge of that scientific connection that allows us to conceive of this intervention in the first place.
Developing an equivalent understanding of the mechanistic functions of sleep seems to me a valuable contribution to scientific knowledge, one that could offer equivalent benefits to human health. At the current time, it seems to me that our understanding in this area is approximately equivalent at best to the British Navy’s early understanding that sour-tasting fruit helps with scurvy. The brain scan data is sort of like having really good anatomical depictions of what healthy and diseased gums look like. As far as I know, we don’t know how we get from sleep to alertness, cognition, or health, or from sleep dysfunction to things like depression or mania, or even what sort of weird compounded things are contained within the sleep-lemon.
I did not see any proposed mechanism for less sleep reducing your need for sleep. (If I missed it, please let me know).
We lack a good idea of why the need for sleep exists in the first place.
If we sleep because there was little to do 100,000 years ago when it’s dark outside and we want to reserve energy, it makes sense to modulate to have a mechanism that modulates the amount of sleep so that people sleep more when it’s dark outside for longer.
I can’t do that with sleep without chemical help, except perhaps delay sleeping for a few hours or sleep a few hours late.
That’s not true. Humans are capable to set intentions to wake up at certain times and wake up at that time. You might personally not have conscious access to the underlying processes the same way you can avoid eating but that doesn’t mean that they aren’t there.
Yep, I sometimes manage to ask my body to wake up at a certain time and it does it when there’s something I care a ton about waking me up a few minutes before the alarm.
This was my thought as well. The problem with candy being a superstimulus is that each time I walk past it in the kitchen I have to exercise willpower to not eat it. While I’m asleep, the reason that I remain asleep is certainly not because I’m somehow giving in to temptation. So the analogy doesn’t work for me.
I do agree w/ Guzey that “sleepiness, like hunger, is normal”. If I’m not feeling tired I stay up.
If anything, the same analogy applied to my personal experience would tell me that ~7 hours of sleep IS normal. For me the analogy looks like:
I only eat when I’m hungry; I eat until I’m satisfied. I’m healthy and not gaining weight.
I only sleep when I’m tired; I sleep until I’m rested. I sleep 7-8 hours on average and am happy with my energy levels.
I see some basic flaws in the sleep-exercise and sleep-food analogies.
There are reasonably well-understood physiological mechanisms showing how slight overuse of muscles starts a process of strengthening those muscles. I did not see any proposed mechanism for less sleep reducing your need for sleep. (If I missed it, please let me know). While it is true of lots of inputs (food, oxygen) I do not think it is defensible to arbitrarily generalize the idea that reduction of any input allows you to function with less of that input.
With the food analogy specifically, there is a much different element of control. I can sit in front of a delicious meal at any time and abstain, even if my body is “telling” me I am starving, or I can eat garbage if my body is “telling me” I am not hungry. I can’t do that with sleep without chemical help, except perhaps delay sleeping for a few hours or sleep a few hours late. My conclusion is that I sleep when my body needs sleep. If I go to bed and 9 hours later wake up naturally, I needed the 9 hours.
Of course, if I wake up and have nothing to do, and decide to stay in bed for another hour, that does not mean my body needed 10 hours. But the 9 hours I had no conscious control over? Yup, my body did what it needed to do.
I think the right conclusion is that you sleep when your body compels sleep, and that your body has a greater ability to compel sleep than it has to compel eating. You have identified your body’s needs with its ability to compel your acquiescence.
This is plausible: we might expect that evolution would equip us with urges in proportion to their importance for survival and reproduction. But we also know that we’re subject to a wide array of dysfunctional compulsions, including drugs, gambling, and anger management problems.
Furthermore, some strong urges serve purposes that aren’t apparent. If you spontaneously start to vomit because of something you ate 6-24 hours earlier, you won’t immediately know which food item triggered the vomiting. Moreover, the vomiting itself is not “what your body needs.” Intead, it’s the clearance of the toxin. A person with a chronic vomiting problem, or let’s say migraine headaches, doesn’t tend to interpret the strong urges to puke or avoid light as “what their body needs,” but as a symptom of a health disorder.
This isn’t to say that the need to sleep is the symptom of a health disorder. Instead, it’s to say that we have a pretty hazy notion of where to put the dividing line between urges and needs, or healthy/enjoyable/excessive/dysfunctional sleep. At least one book has been written seriously arguing for responsible heroin use.
As far as I’m concerned, you can put the dividing line for your own sleep wherever it seems right to you. But if we’re talking about the scientific study of sleep, as Guzey and Matthew Walker are, it’s no longer epistemically permissible to base that decision on one’s personal opinion.
Why might we care to go beyond personal opinion? Consider the analogy of scurvy. A sailor with scurvy doesn’t feel any strong urge to eat Vitamin C pills or suck on a lemon. But it’s a very particular vitamin deficiency they’re experiencing, and it’s the careful study of why lemons and liver prevent and cure scurvy that allows us to get to the heart of the matter. In the time in between the realization that citrus was associated with scurvy prevention, there were a lot of misapplied interventions. It was assumed that the sourness was responsible for scurvy prevention, so sailors were given ineffective limes rather than effective lemons. The juice was piped through copper tubing that destroyed the vitamin and the benefit. The knowledge itself was gained and lost by the naval authorities of the time, even as changes in sailing times decreased scurvy incidence for reasons unrelated to sailor diet.
I for one am happy to know that vitamin C cures scurvy, even though I happen to live in a dietary environment that reliably supplies me with an adequate dose without me needing to ever think about it. I happen to know that folic acid is not routinely added to the maize used by Latino Americans, and for this reason, that community suffers elevated rates of entirely preventable neural tube birth defects. I very much wish that we’d start putting folic acid in maize. But it’s our knowledge of that scientific connection that allows us to conceive of this intervention in the first place.
Developing an equivalent understanding of the mechanistic functions of sleep seems to me a valuable contribution to scientific knowledge, one that could offer equivalent benefits to human health. At the current time, it seems to me that our understanding in this area is approximately equivalent at best to the British Navy’s early understanding that sour-tasting fruit helps with scurvy. The brain scan data is sort of like having really good anatomical depictions of what healthy and diseased gums look like. As far as I know, we don’t know how we get from sleep to alertness, cognition, or health, or from sleep dysfunction to things like depression or mania, or even what sort of weird compounded things are contained within the sleep-lemon.
We lack a good idea of why the need for sleep exists in the first place.
If we sleep because there was little to do 100,000 years ago when it’s dark outside and we want to reserve energy, it makes sense to modulate to have a mechanism that modulates the amount of sleep so that people sleep more when it’s dark outside for longer.
That’s not true. Humans are capable to set intentions to wake up at certain times and wake up at that time. You might personally not have conscious access to the underlying processes the same way you can avoid eating but that doesn’t mean that they aren’t there.
Yep, I sometimes manage to ask my body to wake up at a certain time and it does it when there’s something I care a ton about waking me up a few minutes before the alarm.
This was my thought as well. The problem with candy being a superstimulus is that each time I walk past it in the kitchen I have to exercise willpower to not eat it. While I’m asleep, the reason that I remain asleep is certainly not because I’m somehow giving in to temptation. So the analogy doesn’t work for me.
I do agree w/ Guzey that “sleepiness, like hunger, is normal”. If I’m not feeling tired I stay up.
If anything, the same analogy applied to my personal experience would tell me that ~7 hours of sleep IS normal. For me the analogy looks like:
I only eat when I’m hungry; I eat until I’m satisfied. I’m healthy and not gaining weight.
I only sleep when I’m tired; I sleep until I’m rested. I sleep 7-8 hours on average and am happy with my energy levels.