The National Sleep Foundation vs. American Time Use Survey

The National Sleep Foundation’s annual Sleep in America poll is out today. As usual, the NSF claims Americans aren’t getting enough sleep. “Most say they need about seven and a half hours of sleep to feel their best, but report getting about six hours and 55 minutes of sleep on average weeknights,” the NSF press release notes.

But the good news for those who need 7.5 hours is that another study finds most Americans are getting that. According to the Bureau of Labor Statistics’ American Time Use Survey, Americans sleep, on average, 8.39 hours on weekdays, and 9.33 hours on weekends. The ATUS would include naps in its 24-hour total, whereas the NSF looks at naps separately (and doesn’t seem to report it in the “per night” figure). But in order for these numbers to square, that would mean the average American is napping for almost 90 minutes on weekdays!

I think the difference stems from a different way of asking questions, and shows how serious surveys can come up with drastically different answers. The NSF asks people what time they usually go to bed and usually wake up. They also ask how much they sleep on a usual night. The ATUS asks about a specific day (e.g. March 7). Now some people may be having usual days, and some unusual days on a specific date like March 7, but averaged over thousands of people, this should come out in the wash. But what is “usual” in the context of one person? If I sometimes stay up late to watch TV and sometimes I don’t, which is usual? If I’m supposed to get up at 6:30 but I often hit the snooze button several times, what is my usual wake-up time? This could, in theory, come out in the wash too, but we live in a culture where talking about how sleep deprived you are is a sign of devotion to one’s job, family, etc. Our interpretation of “usual” can be colored by that.