With the arrival of cooler weather comes the resurgence, in catalogs and department stores, of that most dubious of offerings: the two-piece set of pajamas.

Granted, not all pajamas are as hilariously improbable as the collared, button-down shirt, which makes the person wearing it look like he plans to attend a board meeting in dreamland. But even the more casual PJs, the kind that look like something you’d wear to yoga or third-grade gym class, seem way too hot and constricting for sleep.

I have a theory that pajamas were invented for the scenes in TV shows where couples are sitting up in bed talking, but are actually worn by very few real people. To lay around and watch Netflix? Sure. But personally, I’ve never seen a man fall asleep while wearing pajamas. (That is, of course, based on my own small sample.)

(Not too small, but, you know, not the Whitehall Civil Servant study either. A normal amount.)

The data on pajama-donning and -doffing is scant. What is available suggests that nightwear is, indeed, somewhat of a sartorial Potemkin: Worn to give the appearance of propriety before bed, then cast off as soon as most of its wearers hit the sheets.

In 2004, ABC News conducted a telephone poll of 1,501 American adults and found that, contrary to my theory, a nightgown or pajamas were the most common sleepwear option. But just a slight majority of women chose this option, and only 13 percent of men did. Most men said they slept either naked or in their underwear.

What People Wear to Sleep, by Percentage

ABC News / The Atlantic

That poll was 10 years ago, so it's possible that attitudes have shifted since. And it was part of a self-proclaimed “sex survey,” so my personal bet is that there were some respondents who really slept au naturel but were too embarrassed to admit it.

As part of their Global Lifestyle Monitor survey last year, Cotton (as in the fabric) asked 5,000 people in Germany, Italy, and the U.K. how many articles of each type of clothing they owned. Germans reported possessing one fewer set of pajamas in 2014 than in 2012 (three, compared to four), suggesting that the Germans are getting more relaxed, as a people.

Overall, the survey showed that people own fewer sets of pajamas than they do other types of underclothing. That means if they wash their PJs as often as they do other clothing that gets regular, skin-on-fabric action, they must not be wearing jammies very often.

Underwear by Country

Cotton USA / The Atlantic

Americans’ jammy behavior is somewhere in the middle of the pack. British people were far more likely than Americans to admit to sleeping naked, at least according to a 2012 phone survey by the National Sleep Foundation. But Americans don’t seem to be as formal as the Germans or Japanese. The survey found that Americans were less likely to wear nightclothes than either of those countries:

‘What Did You Sleep With On?’

National Sleep Foundation

A less-rigorous survey of British couples by the memory-foam company ErgoFlex found that “two-piece pajama set” was the most popular sleepwear choice, at 37 percent. But again, 19 percent of respondents said they wake up wearing less clothing than they had on when they went to bed.

Further evidence that we’ve reach peak pajama comes from the ICD code for “Deaths caused by exposure to ignition or melting of nightwear.” According to the CDC, fewer Americans are burning up in their pajamas. Is it because fewer are wearing them?

Deaths From Burning Nightwear


This could, though, be a side-effect of the overall decline in house fires and fire deaths since the mid-aughts.

If people are opting out of nightwear, it might be a good thing. There’s a chance these flannel dead-skin receptacles could cause infections if they’re not washed regularly. Perhaps Marilyn Monroe had a point when she said the only thing she wears to sleep is Chanel No. 5.