And here’s more from Brainpickings:
“Six hours’ sleep for a man, seven for a woman, and eight for a fool,” Napoleon famously prescribed. (He would have scoffed at Einstein, then, who was known to require ten hours of sleep for optimal performance.) This perceived superiority of those who can get by on less sleep isn’t just something Napoleon shared with dictators like Hitler and Stalin, it’s an enduring attitude woven into our social norms and expectations, from proverbs about early birds to the basic scheduling structure of education and the workplace. But in Internal Time: Chronotypes, Social Jet Lag, and Why You’re So Tired, a fine addition to these 7 essential books on time, German chronobiologist Till Roenneberg demonstrates through a wealth of research that our sleep patterns have little to do with laziness and other such scorned character flaws, and everything to do with biology.
In fact, each of us possesses a different chronotype — an internal timing type best defined by your midpoint of sleep, or midsleep, which you can calculate by dividing your average sleep duration by two and adding the resulting number to your average bedtime on free days, meaning days when your sleep and waking times are not dictated by the demands of your work or school schedule. For instance, if you go to bed at 11 P.M. and wake up at 7 A.M., add four hours to 11pm and you get 3 A.M. as your midsleep.
Roenneberg traces the evolutionary roots of different sleep cycles and argues that while earlier chronotypes might have had a social advantage in agrarian and industrial societies, today’s world of time-shift work and constant connectivity has invalidated such advantages but left behind the social stigma around later chronotypes.
H/T to Lois McMaster Bujold for the link.
