GirlZZZ and BoyZZZ
Romper ran a piece called "What Is the Gender Sleep Gap? Science Shows Men Get More (& Better) Sleep Than Women." The article, written by Abby Norman, is valuable as a reminder of the fact that men and women have different relationships with sleep. And it handily emphasizes the degree to which inequalities seep into every part of life, including shuteye. But it also glosses over nuances in the xx-xy sleep convo. For instance, it suggests that biology and societal gender expectations shape the way men and women sleep in a somewhat clear and identifiable way.
In reality, researchers have struggled to understand how someone's insomnia complaints might be related to enduring life as a woman vs. being designated female at birth. In all likelihood, both of these factors, plus personality traits, psychosocial characteristics, lifestyle habits, and various other things, are part of the insomniac equation. A tidy (albeit sharable) phrase like gender sleep gap doesn't do much to illuminate such a messy, and at times contradictory, body of research. Here are two specific points I'd like to touch on:
Women actually don't get less sleep than men
They do seem to get worse sleep. And both of these statements can be true without undermining each other.
The article references a recent study in which parenthood was associated with reduced sleep for mothers, but not fathers. It is absolutely true that housework, childcare, and other caretaking duties disproportionately fall on women's shoulders. Coming home to work the "second shift," studies have shown, is associated with sleep complaints and disturbances among women. And it doesn't stop there. There's evidence that women get up during the middle of the night to fulfill their "fourth shift duties." As sociologist Sarah Burgard wrote in a 2013 paper:
Women expect and are expected to take on the “fourth shift” of managing the emotional and practical needs of family members during the night. Their study of 26 working-age U.K. couples with children showed that women were more likely to rise from sleep to do emotional and other care work. A study of 25 U.S. dual-earner, working-class couples under 50 years old also found that women reported more sleep interruptions to provide care for others, even if they worked the night shift.
Other studies similarly emphasize the way unequal distribution of domestic, largely unpaid work takes a toll on women's sleep. But, in the the general adult population, women actually appear to average between 10 and 25 minutes more than men each night. In her own work, Burgard found that women netted about 11 more minutes of sleep than men, on average. (Though, it's worth noting that women spent far less time relaxing and doing leisure activities than men.) Other estimates exceed the 11-minute finding.
- Jawbone data, collected from users in five different countries, found that women sleep about 20 minutes more than men, on average
- Jim Horne, a UK sleep researcher, told me that "Women tend to sleep for around 15 minutes longer than do men, which is more apparent in those younger than 45 years of age, and has been reported in a variety of studies, including ours, as well as from UK National Statistics."
Does it make sense that women have less time for sleep but get more of it? Well, Burgard suggested, women pay more attention to sleep health and take greater effort to compensate for round-the-clock responsibilities by hitting the sack earlier and squeezing in more naps. And, given that women report more sleep interruptions, Burgard said we should be asking if truly equal sleep between men and women (in straight couples) translates to women sleeping, say, 30 or 40 minutes more than men.
It's also worth pointing out that pronounced caretaking duties aren't the only social force shaping how women sleep. Not all women have children or are part of heterosexual couples. (Maybe "parenthood sleep gap" or "motherhood sleep loss" would be a more accurate and to-the-point phrase.)
With that said, getting more sleep isn't the same thing as needing more sleep: The misconception that women need more sleep than men flew around the internet last year thanks to coverage of a "new study" that didn't actually exist. I dug into the myth to figure out where it came from, how it blew up my newsfeed, and see what the science really says about biological differences between sleep in men and women. (The above quote from Jim Horne came from that story.)
It's really hard to extract biology from the sleep equation.
There's no point in ignoring an essentialist truth: Biology does appear to affect how men and women sleep. As the Romper article pointed out, a lot of research on this issue implicates hormones. Women experience the most dramatic sleep changes during periods of hormonal upheaval, including menopause and pregnancy.
In many cases, our knowledge of male-female differences in sleep architecture (how much time is spent in different sleep stages) comes from studies on rodents and fruit flies. Animal models have been valuable for various sleep-research pursuits, including investigations of the relationship between sex steroids, aging, and sleep. But, because humans cycle through sleep differently than mice, among other species, these models don't mimic human sleep behavior perfectly.
A 2014 paper offered a fairly long list of sex and gender differences supported by sleep health research.
- Across normal (non-disordered) sleepers in the general population, sex differences exist in sleep quality, duration, latency, and architecture. Women take longer to fall asleep, report more sleepiness (for the 55-and-under crowd), spend more time in slow-wave sleep, and less time in non-REM light sleep.
- Sleeping disorders afflict men and women differently, both in prevalence and in presentation of symptoms: Women have a 40-percent higher risk than men for insomnia, whereas men are twice as likely to develop Obstructive Sleep Apnea.
- Women metabolize Zolpidem (generic Ambien) twice as slowly as men.
Efforts to identify biological male/female sleep differences still face plenty of barriers. Consider how men and women tend not to report (the same) health problems in the same way. Women are more likely, for instance, to report insomnia and depression (which are linked) starting in puberty.
Insomnia is diagnosed using subjective reports from sleepers, not objective sleep tests. Men, it's been argued, may be less comfortable "complaining" about poor sleep and less likely to connect nighttime tossing and turning with overall well-being and daytime functioning.
And, most of what we know about differences in the way men and women sleep, complain about sleep, and function on a good or bad night's sleep comes from research on heterosexual and cisgender people. This isn't unusual in science, particularly in a relatively new discipline like sleep research. But it does make it tough to say that sex or gender, and not the other, is primarily responsible for sleep habits diverging between a husband and wife.
Still, the Romper piece winds up to a conclusion that's hard to argue with: "There are certainly steps that can be taken to make sure women don't get the brunt of nighttime responsibilities." Yes, there sure are. We don't know precisely how giving women a break on second-shift and fourth-shift duties would affect what the science says about women's sleep. But that's what studies are for.