11 We must all sleep more

These days I often hear people brag­ging about how little they sleep. It is as though sleep is a bad thing and that having as little of it as pos­si­ble is clever¹. It will, per­haps, seem clever to people who sleep less pre­cisely because of what sleep­ing less does to a person: in one phrase, it crip­ples our abil­ity to think clearly. Sleep­ing less is nei­ther a sign of good health nor an indi­ca­tor of clev­er­ness and suc­cess.

More impor­tantly, it must be noted that I am, and have long been, of the opin­ion that sleep­ing is a waste of time because, if we could some­how go with­out sleep­ing, we could use that time pro­duc­tively for some­thing else. But never have I argued that sleep is a bad thing and that we must limit it severely. There is a dif­fer­ence between some­thing being unnec­es­sary and some­thing being a waste of time: if some­thing is unnec­es­sary, it is cer­tainly a waste of time; but if some­thing is a waste of time, it may yet turn out to be nec­es­sary.

The Atlantic pub­lished a won­der­ful arti­cle by James Ham­blin on this topic a few months ago titled How to sleep. It drew on Dr Hamblin’s own expe­ri­ence work­ing over­time as a res­i­dent doctor. He talks, at one point, about a mil­i­tary-led sleep depri­va­tion exper­i­ment that car­ries a tone, and yielded results, sim­i­lar to a number of other exper­i­ments of its type—

Around the (1960s) the U.S. mil­i­tary got inter­ested in sleep-depri­va­tion research: Could sol­diers be trained to func­tion in sus­tained war­fare with very little sleep? The orig­i­nal stud­ies seemed to say yes. But when the mil­i­tary put sol­diers in a lab to make cer­tain they stayed awake, per­for­mance suf­fered … (But) they couldn’t tell that they had a deficit.

“They would insist that they were fine,” said Dinges(^ David Dinges, chief of the divi­sion of sleep and chrono­bi­ol­ogy at the Uni­ver­sity of Penn­syl­va­nia.), ​“but weren’t per­form­ing well at all, and the dis­crep­ancy was extreme.”

… In one study pub­lished in the jour­nal Sleep, researchers kept people just slightly sleep deprived — allow­ing them only six hours to sleep each night — and watched the sub­jects’ per­for­mance on cog­ni­tive tests plum­met. The cru­cial find­ing was that through­out their time in the study, the sixers thought they were func­tion­ing per­fectly well.

Effec­tive sleep habits, like many things, seem to come back to self-aware­ness.

It is the last sen­tence in that excerpt that, I think, sums up the entire arti­cle: often people who sleep less are under the false impres­sion that they are per­fectly alright while objec­tive assess­ment clearly shows oth­er­wise. This is likely what prompts people who look at sleep­ing less as an issue of pres­tige to claim that they are on the right track.

Get­ting seven hours of sleep in a twenty-four-hour day has been sug­gested by quite a few sci­en­tific stud­ies as the sweet spot. How­ever, it is the lower end of a range they advise; adults, as Dr E.J. Olson of the Mayo Clinic puts it, ide­ally need seven to nine hours of sleep. Other stud­ies offer a broader range going from six to ten hours per day.

While, on the one hand, insuf­fi­cient sleep can have neg­a­tive effects most aptly summed as a ​‘drop in per­for­mance’, sleep­ing too much is also a bad thing. A major­ity of stud­ies tend to favour seven hours with some going so far as to claim that nine hours is too much². In any case, any­thing above ten hours is enough sleep to sub­stan­tially increase the risk of depres­sion, dia­betes, heart dis­ease and gen­er­ally lower a person’s lifes­pan.

Sleep require­ments, there­fore, are a trick grey area to say the least. Too little sleep can be bad as can too much of it.

Einstein is known to have slept ten hours every night besides nap­ping during the day for twenty min­utes or so. Beethoven is said to have slept from ten to six, punc­tu­ally. Iron­i­cally, these two are exam­ples of normal humans in this case. There is a rare breed of so-called short sleep­ers who are capa­ble of sur­viv­ing on as little as four hours a day. Nikola Tesla and Leonardo da Vinci are both said to have slept for only a hand­ful of hours each day. Notably, Ben­jamin Franklin, who famously said, ​‘Early to bed and early to rise makes a man healthy, wealthy and wise’, slept six hours a day.

The idea of sleep­ing in short bursts, like Leonardo, is called polypha­sic sleep­ing. Such people prac­tise sleep­ing sev­eral times a day for any­where from five to twenty min­utes each time, totalling about four or five hours a day. The more com­monly seen prac­tice is that of sleep­ing twice a day, once at night and again in the after­noon, which is called bipha­sic sleep­ing. The United States Air Force Research Lab­o­ra­tory itself states a require­ment of eight hours of sleep per day for its troops to ​‘main­tain top-notch per­for­mance’.

One of my favourite com­posers is Mozart, whose sleep pat­terns have been well doc­u­mented in his own let­ters and show a par­tic­u­larly inter­est­ing fluc­tu­a­tion³. He was twenty-one, unem­ployed, living with the Weber family and making money teach­ing others to play instru­ments when he wrote the fol­low­ing letter to his father:

I am writ­ing this at eleven at night, because I have no other leisure time. We cannot very well rise before eight o’clock, for in our rooms (on the ground-floor) it is not light till half-past eight.

It is rea­son­able to assume that that rou­tine would give him a good seven hours of sleep or more. How­ever, five years later, in a letter to his sister, Mozart writes of a dif­fer­ent rou­tine that affords him only five hours of sleep a day:

At six o’clock in the morn­ing I have my hair dressed, and have fin­ished my toilet by seven o’clock. I write till nine. From nine to one I give lessons. I then dine, unless I am invited out, when dinner is usu­ally at two o’clock, some­times at three … I cannot rely on my evening writ­ing, so it is my custom (espe­cially when I come home early) to write for a time before going to bed. I often sit up writ­ing till one, and rise again at six.

This would imply a five-hour sleep rou­tine, but only because Mozart could not afford any more sleep; he never claims, at any point, that sleep­ing less helped him com­pose. How­ever, unlike Mozart, since most claims about Leonardo or Tesla can hardly be accu­rately con­firmed, with most accounts likely having been exag­ger­ated over the years, the sleep habits of suc­cess­ful people living in our own times are, arguably, a better topic of dis­cus­sion.

Forbes reported on this a little over a year ago in an arti­cle by Alice Walton titled ‘The sleep habits of highly suc­cess­ful people’. The arti­cle talks about how much sleep a person needs and exam­ines the sleep sched­ules of suc­cess­ful CEOs, former pres­i­dents etc. citing an inter­est­ing info­graphic⁴ that, inter­est­ingly, claims that Microsoft co-founder and former CEO Bill Gates sleeps seven hours a day, which hap­pens to be the same as Twitter’s Jack Dorsey, Apple’s Tim Cook, and Amazon’s Jeff Bezos.

Argu­ing that clever people sleep less is clearly unfounded⁵. In fact, work­ing more is what makes people suc­cess­ful, not sleep­ing less. And saying that you sleep less by no means sug­gests that you work more when you are awake. Per­haps the reason why some (not all, not even most) famous, suc­cess­ful people ended up sleep­ing less is because they were work­ing a lot, not because sleep­ing less was a great thing.

It does, then, really come down to what an indi­vid­ual needs: some people can do with less sleep, about five to six hours a day, while others need seven to eight hours, whether in one go or two. And sleep itself is not related to suc­cess in anyway. Indeed if you think so, you should prob­a­bly sleep more because insuf­fi­cient sleep might be dis­turb­ing your rea­son­ing.