A common objection to sleep training is a fear of leaving your baby to cry. But what does the science have to say about infant crying and sleep?

There’s nothing as visceral and primal as a baby’s cry...

As parents, we’re programmed to respond emotionally and physiologically to our child's cries. In fact, studies have shown that crying sets off the areas of our brains that drive motivation and social cognition, as well as increasing blood pressure and a rise in stress levels. 

When it comes to baby sleep, we know that parental behaviours play an important role. While it may seem counterintuitive, the research shows that parents who respond immediately to their children’s cries and are more active in soothing their babies to sleep actually have worse sleep outcomes for their little ones.

Studies also show that the most efficient behavioural interventions focus on changing parental behaviours and often involve some infant crying. This led a team of psychologists to suggest that parental sensitivity to crying may play a major role in the development of infant self-soothing and sleep problems.  

Is parents’ tolerance for crying associated with infant sleep problems?

This is what the researchers set out to test with 144 married couples assigned to three groups:

1. Clinical group – parents of babies with night-waking problems
2. Control group – parents of babies with no sleep problems
3. Control group – childless married couples

Researchers assessed the participants’ tolerance to crying through questionnaires, listening to audio of babies crying, and by showing them a video of a baby crying and asking when they would intervene.

The findings ...

The study found that parents who had babies experiencing sleep problems had a lower tolerance to crying, intervened faster, and had a predisposition to a more hands-on approach to settling and resettling. Interestingly, men demonstrated a higher tolerance to crying and were less likely to attribute distress to the crying infant. 

The study is not without its limitations and it’s worth noting that correlation is not causation, so while low tolerance to crying is associated with baby sleep problems, it isn’t necessarily the cause of sleep problems. It may simply be that sleep deprived parents (understandably!) have a higher sensitivity to crying.   

But what this research does show us is that parents can be their own worst enemy when it comes to their baby’s sleep. By rushing in and being very hands-on with settling you may actually be getting in the way of your baby's sleep. 

That’s where we can help. Sleep training is about reducing parental involvement and giving your baby the opportunity to learn to self-soothe. Keep in mind we’re not advocating for neglect or ignoring your baby’s cries. Sleep training involves taking the time to stop, listen, and respond, instead of just reacting automatically.

How to lengthen the time to respond

So you’re struggling not to respond to your baby’s cries immediately – how can you make it easier to lengthen the time you take to respond?

• Use a timer – a minute can feel like a lifetime when your baby is crying; using a timer can help you keep perspective. You can still decide what’s best for you, and at the start you may only be able to last one or two minutes before responding. The goal is to lengthen the time to respond at your own pace, each time giving your little one the chance to settle themselves to sleep.
• Establish a wake up routine – grab your robe and your slippers, have a drink of water, if you're breastfeeding grab a snack. These simple activities will create distraction and delay, allowing your baby time to try to settle back to sleep.
• Go to the toilet – this will give you a few minutes to see what your baby does and if you do end up going in to resettle you won’t have to worry about your bladder.

Tips for dealing with a crying baby trying to settle or re-settle

We know that it’s hard listening to your baby cry and distraction is key. Try:

• Doing the dishes, folding the washing, or cooking dinner – one mum we worked with would leave the dinner dishes and do them when their baby woke in the night. By the time they finished the dishes, the baby had put themself back to sleep!
• Listening to calming music, or a guided meditation - this can help keep you calm and stop you rushing in.
• Getting out of the house – if your partner is a man they probably have a higher tolerance 

for crying so ask them to put the baby down for naps and bedtime so you get out of the house for a walk or a coffee.

Sleep training advice

If you’re thinking about sleep training, here’s our best advice before you start:

• Bank some sleep – this will help increase your tolerance to crying. Don’t be afraid to go to bed at 7:30pm to catch some extra zzz’s.
• Make sure both parents are on the same page – you need to support one another, parents who are conflicted about making changes are our biggest hurdle to success.
• Find your cheerleaders – get the support of friends, family, or one of our sleep consultants to keep you on track.

No parent likes the sound of their baby's cries, but research shows that speedy intervention and over the top stimulating approach's to settling could be doing more harm than good when it comes to your baby's sleep if your goal is self-soothing.

If you want better sleep for your baby, reach out to one of our consultants for one-on-one support and sleep training techniques backed by science.

Emma Purdue

Emma is the owner and founder of Baby Sleep Consultant, she is a Certified Infant and Child Sleep Consultant, Happiest Baby on the Block Educator, Royal Children's Hospital in Melbourne Certificate in Infant Sleep, a Bachelor of Science, and Diploma in Education.

Emma is a mother to 3 children, and loves writing when she isn't working with tired clients and cheering on her team helping thousands of mums just like you.