1 in 3 Americans like to nap

If you find yourself fighting the urge to catch 40 winks in the middle of the day, maybe it's time to start snoozing and stop worrying about what your boss will think. You might be surprised how many co-workers will join you.

Thirty-four percent of Americans take a nap on a typical day, according to the latest Pew Research Center Social & Demographic Trends survey. For men older than 50, the prevalence of napping was 41 percent. The most enthusiastic nappers in the survey were African-Americans; half of those surveyed acknowledged taking a nap in the previous 24 hours.

Napping for as little as 20 or 30 minutes can "improve mood, alertness and performance," according to the National Sleep Foundation. Modern nappers are in good company; Albert Einstein, Thomas Edison, Winston Churchill and Presidents Kennedy and Reagan shared the habit, the foundation says.

Napping is widespread among people in all U.S. regions, according to the survey. Single people are just as likely to nap as married people; so are parents, childless adults and empty-nesters.

Not surprisingly, people who reported trouble sleeping the previous night were more likely to take a nap (41 percent) compared with those who slept well (32 percent). Exercise also seemed to make people sleepy: 37 percent of people who recently had engaged in a vigorous workout said they napped, compared with 30 percent of loafers.

Napping crossed all income levels, but it was most popular among people earning less than $30,000 a year; 42 percent of them said they had napped in the past day. People earning $75,000 to $99,000 apparently were too busy to nap — only 21 percent of them did so — but once income rose past $100,000, napping became an affordable luxury, indulged by 33 percent of those surveyed.

People with jobs were slightly more apt to nap on weekends, while people who were unemployed or retired showed a preference for weekday naps.

The survey found that 18 percent of respondents who described themselves as "very happy" had napped in the previous day, compared with 24 percent of folks who said they were "pretty happy" and 46 percent who said they were "not too happy."

Maybe that's partly because people who reported distress about their financial situation (regardless of income) were twice as likely to have trouble sleeping at night.