Sleep Training by Science: It's Okay to Let Baby Cry

"Cry-it-out" Warnings Debunked

I have already tackled the general science behind parenting practices in the first year of sleep with baby, but the ongoing debate around cry-it-out deserves more attention. I admit I have an emotional and defensive reaction when I read the anti-cry-it-out pieces because I used some extent of this strategy with my children. As I reflect, though, I realize more of my distress stems from an irresponsible issuing of warnings without evidence. And what bothers me about these, are the potential risk this creates for the mental health of mothers, which undoubtedly is the actual risk for babies instead of "cry-it-out."

In my online parenting groups, I would venture to state that sleep is the number one topic. Desperate, sleep-deprived, confused, panicked pleas for help fill the feed. I even see people explicitly state: “if you have a problem with cry-it-out, please just skip over this.” We know that passionate feelings can convert to criticism and judgment, which we probably do enough to ourselves, so we don’t need any more of it from other parents.

I have recently read several online articles describing in very ominous ways the dangers of using cry-it-out as a sleep strategy in the first year. The claims range from causing adulthood aggression to insecure attachments that doom a lifetime of relationships, including between mother and child. There are a range of behavioral sleep strategies now that incorporate letting baby cry, but these pieces use "cry-it-out" as a blanket term for any instance of letting baby cry as part of sleep training.

These studies have universally found not just a lack of negative effects, but positive effects, including BETTER sleep around age one, fewer maternal mental health problems, and improved parent-child relationship.

I trust these authors and people who distribute this information are well-intentioned and passionate about encouraging responsiveness to babies for their optimal health. Whenever I read these articles, though, I feel just as passionately that these kinds of claims and arguments are actually endangering parents, especially mothers, on quite shaky grounds.

As a health psychologist, I have an expertise in sleep (starting AFTER ages 0-5 unfortunately). Every day I work with the reality that sleep functions as central to every part of our functioning: mood, energy, anxiety, fighting off illness, managing stress, even pain. The way our central nervous system is wired, sleep is EVERYTHING.

The biggest transformation I had as a new mother – besides the obvious creation of a new life – was the realization after the first few nights of a totally upended circadian rhythm, that I didn’t have a weekend to look forward to for sleeping in. This was it. I am going to be really tired until . . . I don’t even know.

Of course, all kids are different, and some lucky parents have those that sleep 8 pm to 8 am, but I know I’m not alone with the chronic 6-6:30 am awakenings. The best is when it’s before six on a Saturday because the little buggers have some sort of hidden internal alarm that tells them to get up EVEN earlier on the weekend.

Sleep is everything. Kids don’t let us sleep. Babies let us sleep even less. Combine those factors with all the others in the first year of having a baby (hormones, life adjustment stress), and we have the risk for serious postpartum depression and anxiety. If moms on the brink of a mental health precipice get the message that they have to spend hours not sleeping so they don’t forever harm their children, this is downright dangerous.

There are actually different sleep brains. We are biologically wired to have more or fewer problems with sleep, which explains why my first child slept through the night at age 7 ½ weeks, and my second child woke up multiple times a night for 13 months. I’m the same mom and my husband is the same dad, with the same knowledge and parenting style, but certain approaches worked for my first that didn’t work for my second (like NOTHING worked for my second except waiting until I was done nursing). I used some version of cry-it-out for both of them at different times. My first didn’t really need it very often (meaning it seemed to work), and it didn’t do a darn thing for my second. Are they aggressive, insecurely attached children now forever harmed? No signs of it yet.


I discovered that science backs up my instincts about what nags at me when I read pieces with titles like “The moral imperative to end cry-it-out.” Multiple studies have investigated the concerns that behavioral sleep interventions in infancy have negative effects.

These studies have universally found not just a lack of negative effects, but positive effects, including BETTER sleep around age one, fewer maternal mental health problems, and improved parent-child relationship. Unfortunately, research cited as support for the “moral imperative” was actually a long document on secure attachment geared toward a high-risk population; letting babies cry during sleep training was not part of it.

Until 2012, no study had looked at longer term effects, and the unproven concerns have continued to pervade media. So, as published in the top-tier medical journal for pediatric medicine, Pediatrics, a 5-year study investigated whether behavioral sleep strategies at 7 months (for babies with sleep problems) predicted problems at age 6, with outcomes being child mental health, sleep, psychosocial functioning, stress regulation; child-parent relationship; and maternal mental health and parenting styles. This study followed the gold standard of the best research, with a randomized trial. They concluded: Behavioral sleep techniques have no marked long-lasting effects (positive or negative). Parents and health professionals can confidently use these techniques to reduce the short- to medium-term burden of infant sleep problems and maternal depression.”

I hope to communicate here that in our ringing of alarm bells, we need to have as much compassion for parents as we do for their children. They go together. The better managed a parent’s stress, the better for baby overall. And we need to use caution in making conclusive leaps based on piecing together ideas that do not actually prove the alarm bells.

For example, allowing babies to cry as a sleep training strategy has been conflated with the long-term effects of abuse and neglect. When I worked as an in-home caseworker for families in the child protection system, I witnessed true and tragic neglect. I know what it looks like when a baby is strangely withdrawn, apathetic, and not developing appropriately due to a caregiver systematically not responding to her needs. I have seen children dangerously emotionally dysregulated because they didn’t receive the normal comfort in early years needed to learn how to self-soothe.

A continuous pattern of unhealthy parents not responding to their babies’ needs does not equate with letting the baby cry in an attempt to help everyone sleep better. If a mother (and father) is doing all the usual mother (and father) things – carrying baby, snuggling baby, cooing with baby, singing to baby, picking up baby when he cries – that is responsiveness. It is not cancelled out if the mother (and father) attempt to let the baby cry to save everyone’s sleep.

I am also not arguing that parents SHOULD use cry-it-out methods. I have no horse in the sleep-training race. I support what feels right to the parents, which they are often even confused about, or may shift month to month, week to week . . . hour to hour. I knew when I couldn’t tolerate my baby crying, and I got up and went to her. Parents who do not feel comfortable with cry-it-out should not feel pressured to use it.

Besides world peace and fairer Facebook algorithms, what I want for this world is genuine support for each other as we try to parent and be moms. There is debate whether it actually is the “hardest job in the world,” but none other is so universal.

We all need to be responsible for how we use information so we are not pulling each other down, but propping each other up. Raising children is complicated enough, and we can never say that one factor within that definitely causes some big, terrible future. So let’s stick together on this and remind ourselves we are all doing our best, and for the love of staying afloat, we all need to sleep.


Five-Year Follow-up of Harms and Benefits of Behavioral Infant Sleep Intervention: Randomized Trial, Pediatrics

It’s OK to let your baby cry himself to sleep, study finds,

Help, My Baby Won’t Sleep! (Some useful tips for new parents)

Moms and Sleep (Why women have worse sleep, and what to do about it)

The Art and Science of Sleep: The First Year