That it is not a mere preference but a biological reality is one of the reasons I regard melatonin as so useful—fight fire with fire.
EDIT: Of course, it’s also true that artificial light and computer screens are not helpful in the least: see the second paragraph in http://www.gwern.net/Melatonin#health-performance So you might say for young people, it’s a many-edged problem: they naturally want to go to bed late, their electronic devices exacerbate the original biological problem, and then all the social dynamics can begin to contribute their share of the problem...
I think Vaniver is objecting to the narrow claim of a cycle longer than 24 hours. Without clicking through on your sources, they seem to say that teens have a shifted cycle, not a longer cycle.
In particular, that shifting school later improves sleep suggests that teens have a shifted cycle. If they had an unmoored cycle of longer than 24 hours, the greater light exposure of an earlier start would probably be better.
Douglas_Knight is correct; I’m not challenging “young people want to go to bed late and get up late” but “young people want to sleep six times a week rather than seven” (or, more reasonably, 13 times every two weeks).
I disagree. The circadian rhythms in middle school and up is very well established; please see all the links & citations in http://www.gwern.net/education-is-not-about-learning#school-hours
That it is not a mere preference but a biological reality is one of the reasons I regard melatonin as so useful—fight fire with fire.
EDIT: Of course, it’s also true that artificial light and computer screens are not helpful in the least: see the second paragraph in http://www.gwern.net/Melatonin#health-performance So you might say for young people, it’s a many-edged problem: they naturally want to go to bed late, their electronic devices exacerbate the original biological problem, and then all the social dynamics can begin to contribute their share of the problem...
I think Vaniver is objecting to the narrow claim of a cycle longer than 24 hours. Without clicking through on your sources, they seem to say that teens have a shifted cycle, not a longer cycle.
In particular, that shifting school later improves sleep suggests that teens have a shifted cycle. If they had an unmoored cycle of longer than 24 hours, the greater light exposure of an earlier start would probably be better.
Douglas_Knight is correct; I’m not challenging “young people want to go to bed late and get up late” but “young people want to sleep six times a week rather than seven” (or, more reasonably, 13 times every two weeks).