Breastfeeding hunter-gatherer moms claim they aren't tired

How is this possible?

Most moms will do anything for a little extra sleep. This was certainly true for me. As someone who appreciated a solid nine hours before having kids (especially on weekends), the transition to dealing with a newborn was absolutely brutal. First you have to birth the thing, which is unquestionably the most physically grueling experience a human can go through, and by the time you are done with the 48 hours of the excruciating torture we call “labor” you really feel like you deserve to spend the rest of your life on a beach drinking mango daiquiris. Instead, you have to take care of a newborn baby that never had any intention of sleeping when you’re tired and is only satisfied if you stay awake all night bouncing him on the yoga ball. Or was that just me?

!Kung mother nursing while lying down, from John Marshall’s The Hunters

Regardless of what your postpartum experience was like, I’d be willing to bet my pink KitchenAid mixer on the fact that you were probably tired. That’s why I was so shocked when I came across research on breastfeeding hunter-gatherer mothers suggesting that they do not feel tired in the morning. Are they just flexing (like that super annoying mom in your yoga group), or is this for real?

First of all, I think it’s worth acknowledging that the research on this topic is extremely limited. Of course it is! Why would we spend valuable time and money researching such a niche topic as maternal sleep? I am being facetious, but in truth I can’t help thinking that if we had more women (and especially mothers) doing lab science and anthropology field work, we might have better answers to some of these questions by now. As it stands, most of the anthropologists who studied hunter-gatherers were men, and not many of them thought to study the sleep patterns of breastfeeding mothers. That’s unfortunately true of Western scientific research on this topic as well. When we do have research, it’s usually focused on outcomes for baby, because who really cares whether mom gets a good night’s sleep? In all fairness, the dearth of anthropological research on this topic is partly due to the fact that it feels a bit invasive to ask a Hadza woman if you can cozy up beside her in her grass hut at night and count the number of times she wakes up to breastfeed. But even with the proliferation of technology like wrist actigraphy (a wearable wrist device than can be used to measure sleep patterns) the topic of maternal sleep has remained relatively understudied.

That said, here’s what we do know. The best study we have on the topic of maternal sleep in hunter-gatherer societies was published in the Journal of the National Sleep Foundation in 2018 by Alyssa Crittendon and collaborators. They used wrist actigraphy to measure the sleep quality, sleep-wake activity and sleep duration of 33 Hadza adults, including 21 women, 3 of whom were actively breastfeeding. At the time the study was done (presumably not long before the paper was published) only 150 Hadza were still living as hunter-gatherers, but despite major environmental shifts, sleeping habits had remained unchanged at the time of the research. All Hadza sleep in grass huts during the wet season, and outside under the stars during the dry season, and families always sleep together. They often sleep on skin mats, make a pillow from a mound of earth, use a light covering if it’s cold, and keep a fire burning nearby. Out of 12 married adults with children in the study, they reported having between 3 and 7 co-sleepers on the same skin! The 3 breastfeeding mothers in the study had babies aged 6 months, 8 months, and 18-24 months. All of these mothers reported that their babies breastfed at least once during the night, but none of them felt that their sleep had been disrupted by the feeds. Analysis of the wrist devices showed that the breastfeeding mothers spent an average of 6.8 hours in bed and slept for a total of 6.3 hours, which was similar to both non-breastfeeding women and men in the study. No one in the study napped very much, contrary to popular belief and prior ethnographic observations. Breastfeeding mothers were, however, slightly less active during the day relative to non-breastfeeding women (which correlates with Frank Marlowe’s earlier research on the Hadza showing that fathers compensate for mothers’ reduced foraging activity during the first year of an infant’s life, when breastfeeding takes up much of her time). Interestingly, the only people in the study who said they did not sleep enough at night were two young, newly-married couples (gee, I wonder what they were up to). Families who had more co-sleepers on the family mat also showed more fragmented sleep patterns, but none of them reported feeling sleep-deprived.

These findings are in line with what Melvin Konner reported on the !Kung back in the 1970s. Konner reported, “All !Kung infants slept beside their mothers at night on the same skin mat at least until weaning. In interviews of 21 mothers with children up to age three, 20 reported waking up to nurse at least once a night, and all 21 said that in addition their infants nursed without waking them, from two to ‘many’ times or ‘all night.’”

It’s unfortunate that we don’t have more research on maternal sleep in small-scale societies, and that none of the research included infants. It’s possible that Hadza mothers are just as sleepless as us Western moms in the first few weeks after birth, but then settle into a co-sleeping and breastfeeding routine afterwards. Indeed, Frank Marlowe describes in his ethnography of the Hadza that “it is usually the father who holds a crying infant in the middle of the night and sings to get the infant back to sleep.” Go dads! This suggests that not only do infants indeed wake up and cry in the dead of night, but that mothers benefit from levels of partner support that are sadly quite rare in most other cultures today (again, with the exception of those few annoying moms who married the right guy). Anthropologist George Silberbauer, who studied the G/wi, San people who are closely related to the !Kung, observed, “A G/wi camp never has an uninterrupted night’s sleep. There is always someone awake, adding wood to the household fire, eating a snack, seeing to a child, listening to a strange noise in the bush, or keeping watch if dangerous animals are near” (source). Once again: communal childcare to the rescue, even in the dead of night.

Apart from the communal care, two things stand out to me about this research. First is the amazing fact that hunter-gatherer mothers are seemingly able to breastfeed at night without fully waking up. Equally surprising, however, is the fact that hunter-gatherers apparently don’t sleep all that much. There is a widespread assumption that modern humans sleep less than our Paloelothic ancestors (and less than modern hunter-gatherers) due to electric lighting, TV, and other technology that consistently cuts into our sleep time. This may be partly true, but more recent and accurate data collected on hunter-gatherer sleep using wrist actigraphy tells a different story. A review paper by Yetish and colleagues of sleep in 3 small-scale societies without electricity, all of which relied on actigraphy instead of observation, found that they slept, on average, between 5.7 and 7.1 hours each night (source). This, and other research from small-scale societies, challenges a lot of assumptions we hold about human sleep in the West, and I believe it has important implications for mothers.

For a tour of ancestral sleep, from primates to hunter gatherers to historic accounts of pre-industrial Europeans, stay tuned for the next newsletter. I will try to answer some questions about why we sleep, how humans evolved shorter sleep cycles relative to our primate ancestors, and what the implications are for human health and motherhood. If you have specific questions about sleep, please feel free to ask me in the comments and I will do my best to include answers in upcoming publications. The next week or so will be all about sleep!

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