Here’s one way of thinking about sleep which seems compatible with both the less-sleep-needed thesis and the lower-productivity-while-deprived observation: Some minimal amount of sleep provides a metabolic / cognitive role, and beyond this amount, additional hours of sleep were useful in the evolutionary context to save calories when the additional wakeful hours would not provide pay off.
If true, we’d expect there to a more-or-less fixed function from sleep quantity to sleepiness within the very low sleep range, but in the mid-sleep (5-8 hr?) range this function from quantity to sleepiness would be entirely mediated by stimulation. Stimulation here could mean physical exercise, but I expect excitement / anticipation are also very relevant—in an evolutionary context such feelings signal higher payoff for wakefulness.
The importance of such a perspective, is that reducing sleep quantity would be possible only conditional on the upstream stimulation/excitement variable. Elon, Guzey, highly motivated or active people would all have an easier time avoiding unpleasant struggles to overcome sleepiness. If you are not highly motivated / excited by a given day’s activities there are a few possible implications: 1) simply assume greater sleepiness and give up on economising sleep 2) you could try intermittent physical exercise e.g. periodically doing some squats 3) you could deliberately schedule things which you find exciting / something for late in the day to generate anticipation.
I would be interested to see data on this idea, either by testing strategies (2) and (3) in a psychological study, or by comparing sleep patterns in hunter societies as they vary across time (as a function of hunting opportunity). I think there’s already decent support for this explanation, since it explains the discrepancy between the Elon/Guzey/Sailors anecdata and the fact that most people aren’t happy about missing two hours of sleep. The story also seems to fit well with the depression-treatment result. To make this point clear, one way of putting things is that there’s some excitement/looking-forwardness state which overlaps with the low-sleep state.
Here’s one way of thinking about sleep which seems compatible with both the less-sleep-needed thesis and the lower-productivity-while-deprived observation: Some minimal amount of sleep provides a metabolic / cognitive role, and beyond this amount, additional hours of sleep were useful in the evolutionary context to save calories when the additional wakeful hours would not provide pay off.
If true, we’d expect there to a more-or-less fixed function from sleep quantity to sleepiness within the very low sleep range, but in the mid-sleep (5-8 hr?) range this function from quantity to sleepiness would be entirely mediated by stimulation. Stimulation here could mean physical exercise, but I expect excitement / anticipation are also very relevant—in an evolutionary context such feelings signal higher payoff for wakefulness.
The importance of such a perspective, is that reducing sleep quantity would be possible only conditional on the upstream stimulation/excitement variable. Elon, Guzey, highly motivated or active people would all have an easier time avoiding unpleasant struggles to overcome sleepiness. If you are not highly motivated / excited by a given day’s activities there are a few possible implications: 1) simply assume greater sleepiness and give up on economising sleep 2) you could try intermittent physical exercise e.g. periodically doing some squats 3) you could deliberately schedule things which you find exciting / something for late in the day to generate anticipation.
I would be interested to see data on this idea, either by testing strategies (2) and (3) in a psychological study, or by comparing sleep patterns in hunter societies as they vary across time (as a function of hunting opportunity). I think there’s already decent support for this explanation, since it explains the discrepancy between the Elon/Guzey/Sailors anecdata and the fact that most people aren’t happy about missing two hours of sleep. The story also seems to fit well with the depression-treatment result. To make this point clear, one way of putting things is that there’s some excitement/looking-forwardness state which overlaps with the low-sleep state.