Helping little minds thrive

Cry it out: Should you try it out?


“When it comes to sleep

- more than any other area of parenting - there is a lot of bullshit out there”

You’ve heard of ‘Cry it out’ but it doesn’t sound like much fun for anyone.  And it’s kind of frowned upon isn’t it?  It’s not the sort of thing you hear smug parents bragging about at Baby Sensory that’s for sure.

When it comes to sleep - more than any other area of parenting - there is a lot of bullshit out there.  So when you get to breaking point, what do you do?

As a first-time parent (& neuroscientist) I was frustrated by the over-whelming and contradictory advice out there.  So I decided to review the evidence myself and cut through the muchos crapos out there on what is one of the most guilt-laden decisions new parents face.

What is Cry it out?


You could say most sleep training methods are a form of ‘cry it out’

It’s teaching your little one the behavioural cues they need to get to sleep independently.

We’ve all heard of the renowned self-soothing baby.  That holy grail of a babe who, on waking in the middle of the night, will merely roll over and get themselves back to sleep unaided. 

By three months of age we thought we had it with our first little one, but then the dreaded teething began (she got 20 teeth in 14 months) and self-settling went out the window.  Followed swiftly by its favourite replacement, Calpol.  Hallelujah. 

There are many different methods that claim to help your baby learn to self-soothe.  But pretty much all of them have the same underlining premise; at some point, you will have to let your baby have a go at getting themselves back to sleep alone.  Without you.  And yes, that means they will cry. 

In some ways you could say most sleep training methods are a form of Cry it Out.  It’s just that some fall more on the hardcore end of the spectrum, and others on the more ‘palatable’ end.  To get a taste of the range of options, check out this blog

What’s bad about Cry it out?

The main arguments presented by those against sleep training is that it affects two super important things no parent would want to mess with; cognitive development and attachment.  Let’s look at each of the claims and the evidence backing them up.


Claim 1: It will damage your babies brain

One claim is that sleep training will hinder cognitive development, due to the damaging effect of cortisol (released during crying) on the developing brain. 

Cortisol is a stress hormone released when we experience the fight or flight response that helps to calm the body back down.  Which in normal doses, is a good thing. The problems come when the stress response, and cortisol, are persistently elevated.  Like when you have a stressful job or, erm, a new born child?

Prolonged periods of elevated cortisol can lead to a range of problems from poorer memory and learning, to a propensity for depression and anxiety. This is primarily due to its effects on three key brain regions – the hippocampus (where memories are forged), the prefrontal cortex (important for learning), and the amygdala (the brain’s danger detector and alarm system).  This disrupts how neurons communicate and can even cause brain cells to die.  Yikes.

So prolonged periods of stress certainly can have detrimental effects on the brain.  But most of that evidence comes from studies in animals and adults, not babies.  And certainly not studies looking at the long-term effects of sleep training.


Claim 2: It will make your baby emotionally detached

Studies have repeatedly shown that a mothers’ responsiveness to her child is hugely important for attachment.  Quick, consistent responses to crying result in a more secure attachment style.  And babies who grow up with a secure attachment are more confident to independently explore the world, knowing they have a place of safety to return to when they are in need. 

Nurture in the first six months of life can even affect baby’s genetic makeup, having long lasting effects on their ability to deal with stress, which itself can be passed on genetically to their own children.  

It's clear that parental responsiveness is really important for baby to develop a secure attachment.  And the thing is, sleep training almost always introduces some degree of non-responsive parenting into the mix – at least for a time.  Such as delaying how quickly you respond to their cries.

Are these claims true?

So, after a bout of crying it out, does little newbie end up a few brain cells lighter?  Less able to develop a healthy bond with you?

One of the mostly commonly cited studies by anti-sleep training bods is the English and Romanian Adoptees study. It looks at the long term effects of extreme and persistent neglect experienced by babies raised in Romanian Orphanages, before they were adopted into the UK. 

It’s the babies who spent more than six months in these institutions that the anti-sleep training bods talk about. Those who grew up to show long term cognitive impairments, Autism Spectrum Disorder like traits, and problems regulating cortisol – the very same traits they claim you can expect if you attempt to sleep train your baby. 

But can we really claim that a handful of nights of intermittent crying (in the context of an otherwise utterly nurturing family environment) is the same as spending up to four years in one of these orphanages?  It’s just not comparable.

What’s worse is they’ve actually missed the most important message, which is one of hope.


Fleeting periods of intermittent elevated stress among months of love will not result in any brain damage.

Babies who lived in these orphanages for ‘just’ six months actually showed no long lasting effects.  No cognitive impairment.  No ASD traits.  No stress regulation problems.  That’s despite six months of extreme deprivation during one of the most intense periods of brain development in their life.  They went on to develop healthy attachments in loving families, go to Uni, build careers.  These babes showed extraordinary resilience.  

To me, this study should only provide reassurance to parents tempted by the sleep-training apple.  A fleeting period of intermittent elevated stress among months – years -  of love, attention and care will not result in any brain damage, and it will not damage your bond.

What happens if you don’t sleep train your baby? 

It’s a question often conveniently neglected by the anti-sleep trainers, but an important one, I think.


Prolonged sleep problems are generally bad for parental health and well-being

To be honest the evidence is a little thin on the ground, with studies of varying quality.  But what does seem clear, is that prolonged sleep problems are generally bad for parental health and wellbeing, and are specifically related to maternal depression.  We also know that maternal depression can – in some cases - have at least a small impact on cognitive development.  Because sleep training has been shown to reduce maternal depression, it’s not a huge leap of the imagination to see how better sleep could lead towards happier times for at least the parents, with potentially beneficial downstream effects for baby’s cognition and attachment. 

We still need robust, longitudinal studies to confirm exactly what effects sleep deprivation has on development, but there is some indication that it could affect cognitive development, leading to attention difficulties for example.  Studies of older children certainly show that sleep is hugely important for a whole host of critical things, like growth and learning.  But we don’t yet know exactly how sleep disturbance during infancy effects these things, if at all. 

It’s important to remember that sleep disturbance is itself a hallmark of infancy.  Part of the course.  Would evolution really design infants in such a way that one of their most universal traits (being terrible sleepers) is detrimental to their own development?  It’s hard to see that being the case. 

Overall it seems that while extreme, prolonged sleep deprivation may have some consequences for baby’s cognitive development, it looks like it’s you who’s most likely going to suffer. So an important question to ask yourself might be ‘How much sleep deprivation can I tolerate, whilst remaining a responsive and nurturing parent?’.  If you ever get to the point where you feel your baby’s sleep habits are having a significant impact on your ability to parent, then maybe it’s time to do something about it. 

Does sleep training even work?

Anti-sleep trainers point to methodological flaws in many of the existing studies that claim to show the benefits of sleep training.  And they’re right.  We really do need more and better-quality studies to answer that question.  A pretty sound study (except for the small sample sizes) suggests sleep training methods provide improved sleep outcomes for up to 12 months, with no detrimental effects for the child in terms of cognition, stress regulation or attachment.  The evidence also suggests it’s probably worth waiting until little newbie is at least 6 months before you try, it’s less effective any younger.

So then, should you try it out?

According to the evidence, a bit of sleep training here and there isn’t going to have any long-term negative consequences for little newbie, certainly not in the context of a nurturing family environment. 

At best, it could save you quite a bit of midnight waking when it’s done after six months of age, with potentially big benefits for your own sense of well-being and emotional availability as a parent.   But it doesn’t necessarily last, and it doesn’t necessarily work for everyone.  I can also vouch for the fact that it’s not the most pleasant thing to go through. 

Having said that, oh did I cherish those solid 11 hours of sleep when they arrived…

I’ll leave you to make your own decision.

share your experiences + opinions by commenting below

And continue the conversation on instagram @nurturebabyco_

…Ending on a sweet note

For a snippet of something that is guaranteed to make you feel better about all of this, I strongly urge you to read The Fishy Rods of Shame by the fantastic Hurrah for Gin.  It had me crying and laughing at the same time.

Enjoy :)