Co-sleeping, bed sharing, or whatever else you want to call it – is an abomination of a behavior that no self-respecting mammal engages in. If you don’t believe me, consider how other mammals handle their kids. You know the old can and string phones we used to make as kids? New chimpanzee parents will string a vine between two empty coconut shell halves, placing one half in the baby chimp’s nest in the next tree over and the other half in the parents’ nest, allowing them to monitor the baby’s cries and activity during the night. If the baby wakes up, they’ll swing on over to the other tree and produce a hairy teat until the little chimp quiets down. Then it’s back to bed. The first thing female voles do after giving birth is dig a separate hole in the ground where the infants will sleep. Same with gophers. Kangaroos are famous for their pouches, which for years researchers assumed the mothers used to keep their infants safe, with easy access to the nipples. But in actuality, the kangaroo pouch is used to store shrubs, grasses, various other edible plants, and boxing gloves, as well as cover up their breasts (kangaroos are incredibly shy and modest creatures).
That’s all nonsense, of course, in case you couldn’t tell already. Mammals are huge co-sleepers and bed-sharers. Heck, they exclusively breastfeed, avoid epidurals, give birth at home, and, in the case of marine mammals, are totally into the whole water birth thing. And, from what I understand, the North American deer population is solely responsible for the petition to bring Mothering back to print form (their hooves preclude them from typing, or else they’d totally read the online version). You might say that mammals are the hippies of the animal kingdom. But wait – we’re mammals, too. Doesn’t it make sense for us to share beds with our young children, or maybe share bedrooms? At the very least, shouldn’t we explore the possibility that sleeping with our infants – a behavior that many new parents are drawn toward – is safe and maybe even beneficial?
I’m going to level with you guys before I write anything more: I’m a big proponent of co-sleeping. Carrie and I did it with our kids, and I’m convinced it was the right move. It brought us closer to our kids and to each other. It helped us sleep, when sleep was a hot commodity. I certainly understand why some folks are hesitant to promote or attempt it, but I’m pretty biased in favor of co-sleeping for obvious reasons (it just seems to work).
I gave this topic a brief mention in Monday’s post, and the reader response made me feel like writing a more comprehensive series of posts on the subject was in order. So let’s look at the possible risks and benefits.
Is co-sleeping safe?
First, let’s define co-sleeping. Co-sleeping can refer to three different practices:
Room-sharing, where the baby sleeps in the same room as the parents but in a separate bed/crib.
Bed-sharing, where the baby sleeps in the same bed as the parents.
Couch-sharing, where the baby sleeps with the parent(s) on the couch or sofa.
Are there risks associated with the various types of co-sleeping? Somewhat.
Room-sharing is strongly associated with a reduced risk of sudden infant death syndrome (SIDS), and the American Academy of Pediatrics actually recommends that parents room-share early on. That’s a great start!
Couch-sharing is inherently dangerous, due to the increased chance of the baby falling between the cushions and being pushed up against the back to suffocate.
Bed-sharing is the controversial one. It can be dangerous, if certain precautions aren’t taken, but it also appears to have a host of benefits if done the right way (which I’ll discuss below). Unfortunately, little distinction is made between couch-sharing and bed-sharing when people talk about co-sleeping – even though the two are worlds apart. Even the purported links between bed-sharing and increased danger to the babies are tenuous and confounded by other variables, like drug and alcohol usage, smoking, and poverty. One study, in fact, found that when you control for maternal tobacco usage, the risk vanishes altogether, while a more recent meta-analysis concluded that “there may be an association between bed-sharing and sudden infant death syndrome (SIDS) among smokers (however defined), but the evidence is not as consistent among nonsmokers.” And other studies have found that “non-elective” bed-sharing, where parents (often impoverished single mothers) co-sleep because of circumstance (crib too expensive, tiny apartment, etc.) rather than choice, is a risk for infant death (PDF). But can the results of co-sleeping as it’s often practiced in impoverished, at-risk households where cribs are a luxury and education about safe bed-sharing is nonexistent serve as indictments of co-sleeping in general?
The fact remains that bed-sharing is the evolutionary norm for mammals, including humans. That can’t be argued. According to James McKenna, perhaps the most prolific co-sleeping researcher, “There exist no ethnographic examples outside of Western, industrialized countries of infants sleeping outside the mother’s room—away from her company.” (PDF) If anything, solitary sleeping is the global and historical aberration. Indeed, in many countries and regions where bed-sharing is prevalent and culturally ingrained, like Sweden, Japan, Hong Kong, and Beijing, SIDS rates are low.
If bed-sharing were always a dangerous behavior, I have to think the instinct to do so would have been weeded out and eradicated from most traditions, rather than solidified as a cultural mainstay. After all, killing the young is unequivocally bad for the fitness of a species.
Is co-sleeping worth any potential risks?
Well, let’s look at the benefits.
Co-sleeping makes breastfeeding easier. By now, we all know how hugely beneficial breastfeeding is to a child’s development and health. Breastmilk confers immunological benefits, transfers commensal gut bacteria, and promotes bonding and closeness between mother and child. It’s nutritious (especially if the mother’s diet is nutritious), and it’s the only food everyone agrees we’re designed to consume. Further, breastfeeding is strongly and consistently associated with a lack of SIDS, a link far more consistent than the unclear link between certain types of co-sleeping and SIDS. All signs point to breastfeeding being a good move for both mother and child, so we should promote behaviors that make it easier to do. Across multiple populations and countries, including Sweden, Malaysia, and Brazil, bed-sharing is consistently associated with higher rates of breastfeeding. It may be that women who breastfeed are more likely to co-sleep, but it’s pretty obvious that not having to get up and walk to another room to feed will make breastfeeding easier.
Co-sleeping, particularly bed-sharing, helps mother and child grow attuned to each other’s sleep and awakening patterns. In one study, researchers ran sleep studies on 20 habitual co-sleeping pairs and 15 habitual solitary sleeping pairs. The co-sleepers woke more frequently, but their awakenings tended to overlap (co-sleeping moms and babies woke up at the same time) and the total nocturnal wakefulness was not increased due to decreased duration of awakenings (co-sleeping moms and babies got back to sleep faster). This allowed co-sleeping moms to respond to their children’s cries more quickly and accurately, thereby enhancing their ability to monitor the status of their children and, the researchers suggest, improving their capacity for caregiving.
Co-sleeping improves sleep. Sure, as mentioned above, you might wake up more frequently, but each awakening is far less disruptive since you don’t have to stumble over to an entirely different room in the dark. You slip right back to sleep. Most successful co-sleepers cite “improved sleep” as an important factor in their decision to do it. One study even found that breastfeeding combined with bed-sharing allowed both mother and infant to get more sleep. Some researchers theorize that these “lighter” sleep periods are even protective against SIDS in their own right.
Co-sleeping modifies the parental response to night wakings. One study found that while co-sleepers saw night wakings as normal and nothing to freak out about, parents of solitary sleepers found night wakings to be highly disruptive. If a stressor doesn’t actually register as a stressor, is it stressful? Probably not.
Co-sleeping normalizes the stress response in children. For infants, cortisol regulation in response to physical stress should be “moderate,” rather than heightened. Babies who are solitary sleepers show greater sensitivity to mild stressors, like a bathing session. In response to a stressor, one study showed that the solitary sleepers secreted more cortisol than normal, while the co-slept child secreted the “right” amount. Another study found that co-sleeping had a positive effect on babies’ cortisol regulation at 12 months. Despite “common sense” claims that co-sleeping babies will become more dependent and unable to deal with stressors, the opposite appears to be true.
Co-sleeping facilitates the bond between parent and child. Skin-to-skin contact promotes the release of oxytocin, a powerful hormone and neurotransmitter that solidifies and strengthens the bond between people.
Co-sleeping may result in better-adjusted, more independent children and adults. While you might think that co-sleeping children grow up to be dependent and helpless, most research suggests this is not the case. Some studies even show that children who co-slept as infants grow up to be more self reliant and independent. Others suggest that co-sleeping reduces tantrums, produces less “fearful” children, boosts self-esteem later in life, and helps both males and females become comfortable with intimacy as adults (among many other possible psychological benefits). At the very least, co-sleeping doesn’t create needy, dependent kids.
Next week, I’ll explain how to co-sleep the right, safe way. I’ll also tell you what not to do, along with a few alternatives to bed-sharing. Until then, do what feels right. If you’re intellectually convinced of the benefits of co-sleeping but can’t quite shake the feeling that you’re going to smother your child, don’t co-sleep. It should be a natural behavior that reduces stress, not a cortisol-laden one.
Thanks for reading folks! Be sure to leave your thoughts in the comment section; be civil. This can be a testy subject.
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.