Down with Clickbait: An Empirical Look at Co-sleeping

Photo courtesy of Dennis Yang.

Benjamin Reiss wrote an interesting op-ed earlier this year for the LA Times that was everywhere on my social media.  As the “non-crunchy” friend in a sea of Tula-loving, bedsharing families, I am often bombarded with articles which seem to affirm I am defective to my friends.  I don’t think they actually believe that, it’s just where I’m at when I read this, folks.  I thought the article was interesting.  It explained how wealth and “othering” allowed for the proliferation of the opinion that children who slept alone became better citizens.  This isn’t something we talk about much – unlike the spread of formula which is a somewhat ubiquitous topic of discussion in every gender studies class I’ve been in. Like with the “decision” to formula feed, these choices arise out of a culture and history of “othering”.  While you all know I am a big advocate of formula feeding being a viable option for moms, I will fully admit that the reason most of our moms did not breastfeed was tied up in assumptions about poverty and breastfeeding being “savage” or “gross”.  The same thing was said about bedsharing.

For the record, I totally buy what Reiss is selling in his explanation of history.  There was a lot of orientalist discourse regarding sleeping and feeding habits in the last century.  The “othering” of other cultural choices is an affront to what I believe.  I feel strongly ALL families need to be able to make the right choices for them as long as these choices don’t endanger kids.  No one should be legislating sleeping arrangements.

At the same time, you also know I feel that “romanticizing” the idea of motherhood in the developing world is also terrible.  Not as bad as legislative shaming, sure, but also offensive.  I feel like there is some of that going on.  However, I feel like the most egregious part is the summary remark Reiss makes.

Reiss argues:

“If we raised our children to share space with each other and their parents at night, they might grow up to fight a bit less, share a bit more, and care for others as much as they care for themselves.”

Is there any truth to this?  I would argue, no based on what he cites.  Reiss is citing a study by Worthman and Brown (2007) which has been used to make me feel like a bad mom a handful of times since my kid was born.  As I type this, she is napping in peace in her crib alone. Why?  She refused to fall asleep down here, is already only taking one nap a day, and was running herself ragged.  My kid needs isolation to sleep well.  If I don’t respect that, I am doing her no favors. Of course, plenty of people (including friends) have made mention of studies like this one.  I was told R would grow up to be a criminal if I put her in a crib from day one once.  The evidence of this?  Worthman and Brown’s 2007 study.

Today, I decided to dig in and show you first what Worthman and Brown actually found, what they didn’t, and what their limitations were.  Yes, there is going to be some analysis here but I’m going to do my best to keep it pretty light.  I am sticking to this one study because it is available without a paywall ad seems to be one of the most-referenced in journalistic defenses of co-sleeping (probably, again, because no paywall).

I encourage you to read what Worthman and Brown did.  It’s an interesting study.  The gist of it is that they followed Egyptian families with a variety of sleeping arrangements ranging from only bedsharing/co-sleeping to only solitary sleep.  It’s a very small sample of 16 families but this is divided up by participant (n=parent or child).  They found that co-sleeping could help stabilize sleep but did not provide longer periods of sleep only more consistent periods of sleep with less arousal time.

So, does this mean that co-sleeping makes your kids better citizens?  No.  Reiss’s point is far too overstated.  In no way is that what Worthman and Brown (2007) find.

Here are the limitations that I find should give all of you who have either been shamed by militant bedsharers or who are using this study as a lead weight to justify your own sleeping habits some pause in the future:

  1. Worthman and Brown’s (2007) most novel finding suggesteds the greatest improvement in “sleep disturbance” was among adolescents. When adolescents slept on their own, there was greater disturbance in sleep.  The suggestion the authors make is that the adolescent sleep arrangements of American teens could benefit from some sort of co-sleeping or bedsharing arrangement.  If the person you are arguing with is using this study is using this to support bedsharing with infants or toddlers, they are confused about what the study found.  Note, also, that being male and sleeping alone put teens most at risk because these two terms were highly correlated.
  2. Co-sleeping and bedsharing has a broad definition in this study and the literature compared t how Reiss is using it and how most sanctimommies use it. Worthman and Brown define co-sleeping as any shared sleep arrangement between either parents and children or children of varying ages.  It is not limited to bedsharing (how most American parents define co-sleeping) and includes roomsharing.  Most of the debate I see on social media focuses alone on parents and kids.  The 2007 study shows that teens may even benefit from roomsharing with their siblings.  Thus, bedsharing is not the end-all-be-all of benefits.  Parents do not need to observe the ritual of the family bed for kids to get co-sleeping benefits.  Kids could still sleep in a common room or in a room with one another (something that is still common in many western countries) and benefit.
  3. This study has serious generalizability issues which the authors explain in painstaking detail. This was a look at a few days in a period where school was not in session.  Worthman and Brown write,

“Focal families were each studied for one week during the interval of July 3 – August 4, 2000, beginning just after school year’s end. The period was selected to represent sleep when family schedules are not dictated by school, and when heat is strong yet not at its most severe.”

So, this may not have been practical during the school year with busy scheduled or when things were hot and people didn’t want to be touching.  This was a “best case” co-sleeping scenario.  Also, the small sample size is a huge issue but this was a monumental task for the researchers and we’ve all been there.

  1. Culturally, we are comparing apples to oranges. In the Egyptian case, people have daily afternoon naps when it is very hot.  Many societies have this.  The U.S. does not prize napping.  It’s not an accepted thing to do during the work day.  The researchers note that this, alone, is better for undisrupted late night sleep.  This is a major limitation when it comes to comparison between these two cases.

    Likewise, women in Egypt make up less than a quarter of the workforce.  Thus, if moms are co-sleeping for shorter periods at night but getting naps in the day, this can legitimately be a “sleep when the baby sleeps” situation where women do benefit from more opportunities to sleep in short bouts.  Meanwhile, in the U.S., women make up just shy of half of the workforce.  That means most women are not able to take the opportunity to sleep when the baby sleeps.  As a working mom who relies on sleep to maintain mood stability, I think trying to deal with shorter sleep periods would be very harmful to my health.  The study, after all, was designed at a time when flexibility was highest and when the researchers could see the full benefit of these arrangements.  In all, I think it is difficult to compare this to the U.S. without allowing for the fact that most families here don’t have similar circumstances because most families have their children enrolled in daycare or formal education programs and a large percentage of women are doing some sort of work outside of the home.

  2. There are huge statistical issues here. I won’t get into these because most of my audience doesn’t want to fall asleep at the keyboard.  The author’s encourage everyone take these results with a grain of salt – a strong way to get a publication in a good journal.  We all do it.  However, journalistic accounts of this study ignore all of these things – largely, I would bet, because the writers do not understand what a degree of freedom is.


Overall, there are some major issues with how this study has been explained in clickbait and op-eds.  We all should be very careful when we generalize its findings well beyond where they are applicable.  The media does a poor job of explaining research.  Clickbait exaggerates everything and leads to sanctimommy debates.

Bottom line: Worthman and Brown (2007) don’t say what Reiss takes away from their study – even in the basic sense.  I don’t think that their work shows kids are kinder or more superior when they co-sleep.  They show there may be benefits – especially for male adolescents – to sleeping in rooms with family members.  That is actually a really cool finding no one seems to be talking about.

As I dug into this work, I became intrigued.  My own parents felt very strongly that kids having their own rooms would solve a multitude of problems and would be “better”.  I think most parents do – even I did.  However, there can be some real benefit gained from sibling room sharing I never considered.  I don’t think it should be forced on kids and I think people should listen to older kids who have a need for privacy.  However, I think there is some benefit to more cooperative relationships between parents and siblings.

I still feel that assuming bedsharing is a perfect arrangement with magical properties is ridiculous.  Like breastmilk, it is not going to cure cancer.  No matter what your read on a crunchy parenting site, even the good research in this area is very nuanced and far less black and white (because: science).  When you actually start to read the co-sleeping literature, you start to see that bedsharing is not the only way and that most studies are conducted on populations that do not mirror the one we reside in.

Again, I am not placing a value judgment on other societies being “backwards” or “savage” or “bad”.  I think the Egyptian case study is of note.  But I also realize that women in Egypt face challenges that I don’t.  So, saying this is better may be missing the point.  This may be the optimal sleeping arrangement for parents who do not work outside of the home.  But is it best for women to lack those opportunities and the ability to get the same educational opportunities as men?  I would say no but that’s a normative statement.

We can make a Marxist argument (based on a need to parent a certain way) that the world we live in is essentially bad for families.  There are many, many people who would agree with that.  We do make it incredibly difficult for families in this country.  Learning from some of the Egyptian experience here would probably serve us well – especially when it comes to older kids.  We know poor sleep is related to higher risks of suicide and mental illness (see above as to why this arrangement wouldn’t work for me).  We also know that high school, as it is traditionally laid out, may not work great for adolescents.  They just have different sleep needs than younger kids.

The co-sleeping literature is interesting and I am glad I got to dive into it again.  However, I must tell you – no matter how crunchy (or not crunchy) you may be, it’s really important to realize what the science you are citing means.  Worthman and Brown (2007) don’t affirm what Reiss says.  They also don’t seem to think it is a universal cure-all for the sleep problems of Western children. And they aren’t here to support your argument that if you put your 2 week old into a crib by themselves, they will grow up to be a criminal.  They don’t write about that at all.  I know, big surprise!

For the record, I still think bedsharing with Baby R was incredibly dangerous for us since I needed to take medication and was not breastfeeding.  If someone in my exact situation was bedsharing, I would be concerned for the safety of their very young child.  However, a review of this study reminds me how nuanced co-sleeping is, as defined by the literature, and how there are so many family needs which differ from ours.  I think families who bedshare for their sanity are doing the best thing for them.

I really do wish people would stop talking about bedsharing and co-sleeping as being superior to any other form of sleep because that’s not what the research suggests.  If you are doing so, you are really being no worse than those previous parents who thought making children sleep independently was the only way to raise good kids.

If you want to find a parenting philosophy supported by data, you can definitely find justification for what you are doing in the literature.  I’ve shown that.  However, don’t be so heavy-handed as to assume parenting is ever an exact science.  Supporting claims are much more grey than that and for every claim that supports your philosophy, there are 10 out there someone could hurl at you which don’t.


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