Pulling back the curtain on crying-it-out research

Macall Gordon, M.A.
Nov 7
9 min read

Updated: 9 hours ago

In all the arguing and drama, there are big questions no one has asked.

First, big disclaimer: This is not going to be a for or against the use of crying-it-out (in any of its different forms—Ferber, pop-ins, Sleep Wave, etc.) kind of thing. I’m going to take a giant step back and look through a much bigger lens.

Discussions around sleep training have become so bogged down in heated pro-con debates that we’ve gotten distracted from asking experts some hard questions. Experts make some big promises that simply do not come true for many parents. Rather than ask why this might be, the case, researchers and others chalk it up to parental shortcomings (e.g., can’t withstand crying, they’re inconsistent, or just not doing it right).

We have not stopped to ask why this is the only option for sleep. It can’t technically be “the best one” because there have never been alternatives to compare it to. In most circles, “sleep training” is synonymous with crying-it-out in some form.

The singular focus on just one approach is curious when you think about it.

It's true that, for many families, crying-it-out works quickly and easily. It’s a few nights of very little drama and—boom—they’re done with the whole process. For anyone who has found success, and it was not a nightmare, I say, “That's awesome.” To anyone who had an easy-ish time with sleep overall or achieved it without a major struggle, I am thrilled for you.

A sad baby rests on a textured blanket, hand on cheek, gazing directly with wide eyes. Monochrome image emphasizing expression.

However . . .

There are many, many parents who are not having an easy time. Research suggests that in the real world, 30-50% of parents who attempt crying-it-out said that it didn’t work at all (Gordon, 2020; Loutzenhiser et al., 2014). Even in research studies, it didn’t work for 20-50% of the sample (Gordon, 2023). Are all these parents “doing it wrong”? Or is it possible that crying-it-out doesn't actually work for everyone?

Here’s another dirty little secret no one talks about: most parents hate it. No one looks forward to letting their baby cry. For many parents, it’s a non-starter. Researchers have known for decades that parents don’t like it, but appear baffled at their resistance. Whole papers have been written about how to talk parents into it or “increase their tolerance for crying.”

It begs the question: If the method is so great, why do we have to work so hard to convince parents to do it?

Sleep training advice: What hasn’t change in 40 years

Over the past 40 years, sleep training advice has not changed one bit despite new understandings of brain development and regulatory capacities. Not only is advice the same across time, but messaging is startlingly consistent across sources. While it may seem like there are a hundred different methods, the rationale behind them and the basic structure of the interventions are almost identical.

I’ve spent the past 20 years looking at both the content of sleep advice and the research that it’s based on. Across sources, the line of thinking usually goes like this:

Sleep problems are common and cause serious short- and long-term problems
Parents are the cause of these problems
“Better sleep makes better babies” (i.e., babies who sleep are calm, compliant, “fun to be around”) and “bad sleep makes difficult babies” (i.e., cranky, tough to handle, and vulnerable to later psychopathology)
You have to start early to prevent problems from taking root
The most evidence-based approach is extinction (versions of crying-it-out), which is quick, effective, and without negative side effects.

Why the “party line”?

Advice has been driven by research, and the research itself is of one mind. Research is about publication, and for researchers, it’s better to build on work that’s already been established than to start something new. The earliest research on sleep training was based in behaviorism.

Nearly 100% of subsequent work has been conducted within this same theoretical framework. In fact, an entirely new field has emerged out of this work called behavioral sleep medicine with accompanying diagnoses: sleep onset association disorder, behavioral insomnia, limit setting disorder (this one is applied to the parents).

The 100-year-old theory behind sleep training

Behaviorism is a theory from the 1920s that says that infants enter the world as blank slates, without instincts or inborn traits. Everything, they said, was learned from the environment. The original theorist, John Watson, believed he could train any baby to grow into whatever kind of adult he liked. Behaviorism says that if there is an unwanted behavior, simply withhold the response for that behavior (the reinforcement), and it will go away (it will be extinguished).

Sounds familiar, right?

You’ll recognize this from just about every book ever written on sleep training. To eliminate crying at bedtime or during the night, you have to leave the room, stop responding, and they’ll eventually give up and go to sleep. Today, experts will say that this is “teaching a baby to self-soothe,” but really, it’s altering their response (crying) by removing the reinforcement (parental presence and soothing). It’s simple behavior modification.

Behaviorism also believes that the only active ingredient in any interaction is behavior and response, not development or temperament or biology or the family system. None of that is relevant. In this framework, the age of the child, the amount of crying, or their feeding status are not considered. What we’re left with, then, is 100% parental responsibility for outcomes. Because if nothing else counts except for the reinforcement of a behavior, the parent is the only active ingredient. This is why the method is never at fault. Even in research, when the study was not successful, researchers blamed the parents (e.g., more psychopathology, didn’t follow the protocol, etc.). This is important to highlight: In this theoretical model, the method is never wrong.

Sleep is more than just behavior

We know better than this. We know that there are many variables that impact sleep besides what a parent does or doesn’t do. However, even modern sleep-training books rarely give parents any information about what to do if the intervention isn’t working. The message continues to be: If done correctly, this works 100% of the time. With the unspoken subtext: If it doesn’t work, you’re not doing it right.

There’s so much about behaviorism that we would consider outdated or out of step with current knowledge about how children learn and develop. Nevertheless, it’s still the driving force in infant sleep research and advice, and strongly present in the way parents are made to think about sleep, as behavior-response rather than a system of interacting variables.

It’s time we stopped to ask why we’re still using a century-old theory to guide our current thinking on infant sleep.

Real-world impacts on parents

The overemphasis on a behavioral paradigm has had tangible negative impacts on parents.

Parents are now overly worried about “avoiding bad habits” even with newborn babies.
Parents blame themselves when crying-it-out isn’t “easy” or “quick.”
The focus on behavior causes diagnosable conditions to be overlooked or dismissed by medical professionals. I’ve spoken to so many parents of infants with obstructed breathing or silent reflux who were told by the pediatrician, “You just have to sleep train.”
The behavioral bias of the sleep industry has prevented the investigation of alternatives for parents who don’t want to use crying-it-out or for whom it didn’t work.

It’s time to really take a hard look at how we got here and ask some important questions. Sleep books make big promises that extinction is quick, effective, and has no negative side effects. Many parents’ lived experiences beg to differ. What do we actually know about crying-it-out from research? And does it map to the real world of parents at home with their baby?

Hang onto your hat. The Emperor may have fewer clothes on than you’ve been told.

Coming up. . .

Given that this is the product of a couple of decades of work and the Emperor is wayyy more naked than you’d think, this is going to be a five-part series where I talk about the problems with what we actually know about each of the claims contained in mainstream sleep advice.

In Installment Two, I want to talk about how we got here. What are the roots of all of this unanimous sleep advice, and what are some of the cultural and economic forces that have kept it running?

Installment Three will look at what we know about the push to start sleep training early. Some books now tell parents they can start crying-it-out as early as eight weeks. What does the research say about that? What do we know from research about the effectiveness of starting this work early and the need to do so?

Installment Four will examine the claims in sleep training advice. Is crying-it-out as “quick” and “effective” as they say? What’s the research, and what does “effective” mean in terms of measurable extra minutes of sleep? There’s a big difference between what researchers and parents might consider “effective.”

Finally, Installment Five looks at how negative side effects have been examined. This one will not be about showing that crying-it-out is harmful. However, how researchers have looked for side effects may be different than you think. What do we know about how much crying is not harmful?

At what ages? How confident are we that there really aren’t any…ever?

Stayed tuned for Installment Two.

If you’re interested in my review of the research, you can find the academic versions here.

Original project: “Crying it out:” A critical review of the literature on the use of extinction with infants.

Updated project: Examining the congruence between research, advice, and parenting practice on the use of extinction (crying it out) for infant sleep: A review of the literature

Here’s a podcast where I’ve discussed this topic: Your Parenting Mojo

I also have a YouTube video on this topic that you can view below.

Need help with sleep…without crying-it-out?

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About Macall Gordon

Macall Gordon has a B.S. from Stanford in Human Biology and an M.A. from Antioch University, Seattle in Applied Psychology, where she is currently a Sr. Lecturer in the mental health counseling department. She is a researcher looking at the relationship between temperament and sleep, and the gap between research and parenting advice on sleep training, and the effect of the oversupply of expert advice on sleep. She is a certified pediatric sleep consultant working with parents of alert, non-sleeping children in private practice, as well as on the women’s telehealth platform, Maven Clinic. She comes to this work because she had two sensitive, intense children, and she didn’t sleep for 18 years.

She recently presented this work at the World Infant Mental Health conference in Dublin, Ireland.

References

Gordon, M. D. (2023, July). Parental experiences with the promises of extinction to prevent infant sleep problems: A review of the literature. Paper presented at the World Infant Mental Health Conference. Dublin, Ireland. July 14-17, 2023.

Gordon, M. D. (2020, October). The effect of difficult temperament on experiences with infant sleep and sleep training: A survey of parents. Poster presented at the Occasional Temperament Conference. University of Virginia (Virtual).

Loutzenhiser, L., Hoffman, J., & Beatch, J. (2014). Parental perceptions of the effectiveness of graduated extinction in reducing infant night-wakings. Journal of Reproductive and Infant Psychology, 32(3), 282–291

FAQ: Pulling back the curtain on crying-it-out research

1. Does the cry-it-out method really help babies sleep through the night?

Not always. Research shows that 30–50% of parents who try the cry-it-out method (also known as extinction or CIO) said it didn’t work for them. While some babies do learn to fall asleep and maintain good sleep habits quickly, families may find that the method of sleep training doesn’t match their baby’s temperament or needs. The assumption that every baby will respond the same way overlooks biology, feeding, and development, all of which affect how and when babies learn to sleep longer stretches.

2. How is graduated extinction (like the Ferber method) supposed to work?

The Ferber method and other sleep training techniques are based on behaviorism, a 100-year-old theory that says unwanted behaviors fade when you stop responding to them. Parents are told to leave the room for increasing intervals, allowing their baby to cry for a set amount of time before returning briefly. The idea is that babies will learn to fall asleep on their own once they realize crying doesn’t bring a response. However, studies show wide variation in how long it takes for this method to work, and for many families, it doesn’t result in the promised quick or lasting results.

3. What if the method doesn’t work or feels wrong for our family?

That’s a common experience. Even in studies, a large number of parents report that these approaches were stressful or ineffective. If your bedtime routine and sleep habits feel out of sync with your child’s temperament, it doesn’t mean you’ve failed. It may mean that sleep training method isn’t the right fit. There are gradual approaches that allow you to put your baby to sleep while staying close, reducing distress without forcing you to leave the room or ignore cries. The key is finding a plan that supports your child’s development, and your own peace of mind.