Let the people sleep
One of my first due diligence conversations for this research fellowship:
Me: What kind of hours do you work? (Because you know, I’m not trying to bust my ass during my year off).
Previous Research Fellow: it’s an 8:30–6 kind of deal on most days, and every other week you’ll have 1–2 evening calls that go from 9–10:30pm or so. When it gets busy, you might have to put in some evenings or weekends
Me: That…sounds like a lot.
PRF: Oh but there’s built in nap time.
Me: What?
PRF: From 12–2:30pm every day!
Me: Where do I sign?
Nap time! Every single day! Civilization has arrived!
Actually, I thought this was super weird when I first got here. Every day at noon on the dot, everyone goes to lunch. We eat for about a half hour, and then we head back upstairs, lights out, AC off, and bam, the entire room is asleep within minutes. Sleeping positions vary considerably: some people are die-hard head-on-desk nappers. Others outfit themselves with the complete package: folding futon, blanket and pillow, stretched out across our floor space. When a new post-doc arrived at our office, he looked around and immediately asked, “How do you guys nap?” I gave him a weird look and was kind of like, “Put your head on the desk, fool.” But my co-fellow who used to work in Yunnan (very serious nappers according to him) told me that many offices have nap rooms with designated beds so that everyone has a place to sleep. He himself is a great believer in napping in a horizontal position — none of that head-on-desk nonsense.

This is a country that encourages “afternoon rest” from 12–2:30 every working day. At government-run organizations, including hospitals, afternoon rest is a commonly practiced right. Factories have started sanctioning naps as part of workers’ rights reform. In the US, we have an antipathy toward sleeping in public. I’ve never quite figured out the cause: perhaps some combination of commitment to professionalism and hesitation to exhibit vulnerability? But here, napping in public, anytime, anywhere, is considered totally normal. Chinese people nap everywhere and will eviscerate anyone who threatens their right to nap. Even Ikea gave in to China’s fierce commitment to napping. But more of the country is bending to capitalist pressure to work through the day, especially at foreign companies (this is probably the real reason why the Chinese government opposes unchecked capitalism.)

Nap culture isn’t limited to China, of course. We’ve all heard of the siesta in Spain, said to have originated due to the weather, which gets unbearably hot mid-day (Spain-faring friends — would love your take on this). In Japan, napping in public is a sign of diligence — as in, you’ve been working so hard that you can’t possibly stay awake but still want to be present (this scenario very accurately describes me at grand rounds, but for some reason no one ever gives me props for sleeping through them).
It’s unclear why cultures disagree on naps: the literature is pretty ambivalent on physiologic differences playing a role. No one else has proposed any plausible reasons for the difference either (although some people have proposed implausible reasons). We’ve all heard about the importance of sleep: sufficient sleep — that’s 7–9 hours per night depending on the individual — has been associated with physical health benefits, like improved cardiovascular health, glucose tolerance, weight control, and immune response; as well as cognitive and mental health benefits, like improved concentration, learning, memory, and mood (a totally underrated one). But what does the literature have to say about naps?
A lot, as it turns out. First, there’s a decent amount of work showing improved cognition after a short nap in populations with disturbed sleep cycles — think shift workers, pilots, and residents. In older populations, the results are more controversial: some researchers are concerned that elderly adults who take evening naps are more likely to suffer from poor sleep overnight. There’s also some scattered literature showing improved muscle memory and learning after napping. In general, 10–30 minute power naps seem to be ideal: any longer, and you run the risk of sleep inertia.
So far so good. But then it gets weird: there’s a whole body of literature out of China, Japan, and the UK suggesting that daytime napping is associated with cardiovascular disease, diabetes, obesity, and all-cause mortality. I guess I was wrong about exercise and white rice playing a role in the diabetes epidemic in China — the real culprit is napping. Japanese researchers have even broken down the time frame for you: keep your naps under 40 minutes if you don’t want diabetes; under 30 minutes if you don’t want to die.
Yes, I know I’m being hard on them: it’s not easy to do controlled trials on sleep because there’s no money in it. The available data on sleeping habits is inevitably self-reported and observational, highly subject to confounding variables. In this particular case, I haven’t looked too far into the weeds, but there are probably inflammatory processes that are contributing both to noncommunicable disease as well as decreased wakefulness. To be fair, the authors are usually careful to distinguish association from causation. And it’s true that longer naps are likely to lead to sleep inertia. But this is exactly the type of finding that the media is likely to jump on, leading to outrageously sensational headlines from news sources that I respect.
So much for bringing the nap culture to America.
I guess I’d better treasure the sanctity of the afternoon nap while I can. For all my friends who find it really strange that I can fall asleep anywhere instantaneously: SEE, IT’S NOT JUST ME. Stop taking pictures of us sleeping in the library.
Update from last week: finally found a few Tampax, the elusive creatures

