Can Sleep Training Damage Attachment? What the Research Actually Says

If you have ever considered getting support with your baby's sleep, there is a good chance you have also had this thought:

“What if helping my baby sleep damages our attachment?”

It is one of the most common concerns I hear from parents.

When you are already exhausted and overwhelmed, the last thing you want to feel is that improving your baby's sleep could come at the expense of your relationship with them.

Many parents worry that if their baby cries, sleeps independently, or no longer needs to be rocked or fed to sleep, they are somehow weakening the bond they have worked so hard to build.

So let us take a step back from social media debates and look at what attachment research actually tells us.

Because attachment is much bigger than what happens at bedtime.

What does attachment actually mean?

Attachment is the emotional relationship that develops between a child and their caregiver. It provides a foundation of safety from which children can explore, learn, develop and gradually become more independent.

A securely attached child does not need their parent physically beside them every moment of the day to feel safe.

Instead, their caregiver becomes a secure base.

They know that their parent is available, responsive and there when they need comfort and support.

This concept comes from the foundational work of John Bowlby and Mary Ainsworth and has been supported by decades of attachment research. The secure base relationship allows children to move between seeking proximity to their caregiver and confidently exploring their environment.

More recent research continues to show that sensitive and responsive caregiving is strongly associated with secure attachment. A 2024 meta analysis involving more than 22,000 parent child dyads found a positive association between caregiver sensitivity and attachment security.

That is an important distinction.

Secure attachment is not about constant physical proximity. It is about the quality and responsiveness of the relationship.

Attachment theory is not the same as attachment parenting

A lot of confusion surrounding infant sleep comes from treating attachment theory and attachment parenting as though they are the same thing.

They are not.

Attachment theory is a psychological framework developed through the work of researchers including John Bowlby and Mary Ainsworth.

Attachment parenting is a particular parenting philosophy associated with practices such as breastfeeding, babywearing, contact napping and bed sharing.

These choices can be wonderful for families who enjoy them. However, they are not a checklist for secure attachment.

There is no evidence that a parent must breastfeed, contact nap, bed share or remain physically present throughout sleep in order to develop a secure attachment.

Likewise, there is no good evidence that helping a baby develop independent sleep skills automatically damages attachment.

Attachment develops through the relationship as a whole, across thousands of interactions over time.

Does one difficult night damage attachment?

This is where parents often put enormous pressure on themselves.

They worry that one difficult bedtime, one period of crying, or one change in their baby's routine could permanently affect their relationship.

But attachment is not that fragile.

Children do not need perfect parents. They need caregivers who are consistently responsive enough over time.

There will be moments when your baby cries and you cannot immediately make everything better.

There will be times when your toddler becomes frustrated.

There will be days when you are tired, touched out or simply need a moment to yourself.

These experiences are part of ordinary childhood and family life.

What matters is the overall pattern of caregiving and the relationship you build with your child.

Research consistently highlights responsive caregiving and caregiver sensitivity as important contributors to attachment security.

What about sleep training and attachment?

This is perhaps the most important question.

There is now research specifically examining whether behavioural sleep interventions have negative effects on infant attachment.

One randomised controlled trial published in Pediatrics followed 43 infants between 6 and 16 months who were assigned to graduated extinction, bedtime fading or a sleep education control group.

The researchers assessed infant sleep, cortisol, maternal stress, emotional and behavioural outcomes and parent child attachment.

The result?

The sleep interventions improved aspects of infant sleep. The researchers found no significant differences in attachment security, emotional or behavioural outcomes at the 12 month follow up. They also found no evidence of adverse stress responses associated with the interventions studied.

This does not mean that every sleep approach is appropriate for every family.

It does mean that the claim “sleep intervention causes insecure attachment” is not supported by this randomised trial.

There is also longer term evidence.

A five year follow up of a randomised trial involving behavioural infant sleep interventions found no evidence of differences between intervention and control groups in child mental health, stress regulation, parent child relationship, attachment, or maternal mental health.

That is particularly reassuring because it looked beyond the immediate sleep period and examined outcomes years later.

But what about cortisol?

This is another topic that understandably worries parents.

You may have seen statements online claiming that sleep training causes dangerously high cortisol levels or that a baby can stop crying while remaining extremely stressed internally.

Cortisol is often referred to as the “stress hormone”, but it is a normal hormone involved in many everyday physiological processes. Cortisol naturally changes throughout the day and responds to a wide range of experiences.

One frequently cited study by Middlemiss and colleagues examined 25 infants participating in a five day inpatient sleep training programme. The study found that on the third day, infants' behavioural distress had reduced while cortisol remained elevated.

This study is worth discussing, but it is also important not to interpret it as proof that sleep training causes psychological harm.

The study involved only 25 infants, took place in an inpatient setting, and involved nurses providing the sleep intervention rather than parents conducting the bedtime routine at home. The researchers measured cortisol on only selected days and did not measure attachment outcomes in that analysis.

Most importantly, an elevated cortisol measurement does not by itself demonstrate trauma, attachment damage or long term psychological harm.

And subsequent research has provided a different picture.

In the randomised controlled trial mentioned above, cortisol levels actually showed small to moderate declines in the behavioural intervention groups compared with controls. The researchers found no evidence of adverse stress responses or later attachment problems.

So the evidence is considerably more nuanced than the statement “sleep training causes harmful cortisol.”

Crying is not the same as trauma

This distinction is incredibly important.

Babies and children cry when they are frustrated, tired, uncomfortable, overwhelmed or adjusting to something new.

Crying is communication.

It does not automatically tell us what a child is experiencing emotionally, and crying alone cannot be used as evidence that a child is being traumatised.

Children encounter frustration as they learn and develop.

They may cry when they start childcare.

They may cry when a parent leaves the room.

They may cry when learning to crawl, walk or communicate.

They may cry when they hear the word “no”.

Our role is not to prevent every moment of frustration. Our role is to provide appropriate support, safety and connection while they develop new skills.

The same principle can apply to sleep.

That does not mean ignoring a child's needs or leaving a distressed child without support.

It means recognising that some protest during a change does not automatically mean that the change is harmful.

Sleep is a developmental skill too

We accept that children need support while learning many new skills.

We do not expect a baby to crawl perfectly on the first attempt.

We do not expect a toddler to immediately manage every emotion.

We do not expect a child starting school to feel completely comfortable on their first day.

Sleep can be approached in much the same way.

Some children need more support than others.

Some families choose a very gradual approach.

Some choose responsive settling.

Some choose parental presence.

Some choose to work on bedtime first and night wakings later.

There is no single approach that works for every child or every family.

The goal should not be to force independence.

The goal is to help a child develop sleep skills in a way that respects their temperament, developmental stage and the family's circumstances.

What about the parent?

This part of the conversation is often overlooked.

Infant sleep does not only affect babies.

Persistent sleep difficulties can affect parental sleep, mood and wellbeing. Research examining psychosocial sleep interventions has found improvements in infant sleep as well as improvements in maternal mood. A 2023 systematic review and meta analysis of 13 studies found that psychosocial sleep interventions improved infant nighttime sleep duration and were associated with improvements in maternal depression.

And this matters because parents are part of the attachment relationship.

Attachment is not created by a baby alone.

It develops within the relationship between child and caregiver.

If chronic sleep deprivation leaves a parent struggling with patience, emotional availability or their ability to enjoy everyday interactions, that deserves to be taken seriously too.

Supporting a family's sleep is not about choosing the parent over the baby.

It is about supporting the wellbeing of the whole family.

Independent sleep does not mean less connection

One of the things I hear most often is:

“But rocking my baby to sleep is our special bonding time.”

And sometimes it genuinely is.

There is absolutely nothing wrong with enjoying those cuddles when they work for your family.

But if bedtime has become something you dread, if you are spending hours trying to get your baby to sleep, or if you are so exhausted that you are struggling to enjoy your days together, it is worth considering whether there is another way.

Changing a sleep association does not mean removing connection.

You can still connect through:

• Bedtime stories

• Songs and nursery rhymes

• Cuddles and kisses

• Talking and singing to your baby

• One on one play

• Bath time

• Morning cuddles

• Contact naps when you want them

• Carrier walks

• Family routines

• Responsive comfort when your child needs you

The relationship does not disappear because your baby learns to fall asleep in a different way.

The love remains. The connection remains. The attachment remains.

You are simply changing how sleep happens.

So, can sleep support damage attachment?

Based on the research we currently have, there is no good evidence that appropriately implemented behavioural sleep interventions inherently damage parent child attachment.

Randomised research has found no significant differences in attachment security following commonly studied sleep interventions, and longer term follow up has found no evidence of harm to parent child relationships or child emotional wellbeing.

At the same time, research should not be used to tell every family that they must sleep train.

You do not have to use a particular sleep approach.

You do not have to leave your baby to cry.

You do not have to aim for independent sleep if your current arrangement is working well for your family.

And you do not have to continue struggling simply because you are afraid that wanting more sleep makes you a less responsive parent.

There is room for both.

You can want your baby to feel safe and secure.

You can respond to their needs.

You can protect your relationship.

And you can also want better sleep.

These things are not mutually exclusive.

At CozySleeps, I believe sleep support should never be about forcing a child into independence or asking parents to ignore their instincts.

It should be about understanding your child, responding to their individual needs and finding a sustainable approach that allows everyone to get more rest while maintaining connection.

Because supporting your child's sleep does not mean loving them less.

Sometimes, it simply means helping the whole family sleep better so that you can have more energy to enjoy the moments that matter when everyone is awake.

Better sleep and a secure attachment can absolutely coexist.

A note on the research: Sleep research continues to evolve, and no single study can answer every question about infant sleep and attachment. The research cited below represents some of the evidence currently available on sleep interventions, attachment, caregiver wellbeing and infant stress.

References

1. Gradisar, M. et al. (2016). Behavioral Interventions for Infant Sleep Problems: A Randomized Controlled Trial. Pediatrics, 137(6).

2. Price, A. M. H. et al. (2012). Five year follow up of harms and benefits of behavioural infant sleep intervention: randomised trial. Pediatrics.

3. Middlemiss, W. et al. (2012). Asynchrony of mother infant hypothalamic pituitary adrenal axis activity following extinction of infant crying responses induced during the transition to sleep. Early Human Development, 88(4), 227 to 232.

4. Han, L. et al. (2023). Effects of psychosocial sleep interventions on improving infant sleep and maternal sleep and mood: A systematic review and meta analysis. Sleep Health, 9(5), 662 to 671.

5. Madigan, S. et al. (2024). Maternal and paternal sensitivity: Key determinants of child attachment security examined through meta analysis.