Parents have been worried about their kids' sleep since time immemorial.
And for valid reasons — good sleep is an essential part of a healthy childhood.
Sleep is critical for physical growth, but also for many other aspects of brain development, learning and the development of important social skills.
Children observe, experience or are taught things during the day, but they really only 'learn' overnight while they're asleep.
In an increasingly digital world full of ubiquitous devices, the impact of technology on kids' sleep is of particular concern.
More children are using devices, and at an earlier age.
This raises many questions about the costs and benefits of technology for healthy development.
On one hand, parents and carers want children to learn as much as they can, be up-to-date and competent with technology, and be connected in new and meaningful ways with their families and friends.
On the other hand, increased screen time seems to be linked with decreased physical activity, poorer overall health, an increase in mental health and wellbeing concerns and poorer sleep.
Poor sleep has many costs. In the short term, tiredness can lead to irritability, meltdowns and poor concentration, and in the long term it can lead to increased risks for a range of health, social and wellbeing challenges.
It is still not clear exactly how technology can impact kids' sleep, but researchers have some ideas to test out.
What role does technology play in your home?
Technology is not a new visitor to our homes.
It has been evolving over time — at least from the advent of artificial lighting to radio, television, gaming consoles and podcasts.
Even more traditional activities such as reading might have sometimes carried on into the night.
Kids' sleep has been a concern of parents right across this period.
Children's sleep can be perplexing because it changes so much from birth through to the teenage years.
The development from the almost 24-hour, anytime sleep of babies, through to regular naps in toddlers, then the end of daytime naps happens at different times for different children.
Children need a lot more sleep than adults do, and getting enough sleep at the right time can be challenging when there are a lot of demands on the time of children and their families.
Children and young people grow up in all sorts of different environments, places and circumstances. They also have their own individual personalities and preferences.
At the same time, very significant global challenges — from pandemics to wars to climate change — will have impacts on their lives.
This means it can be difficult to know if technology is 'good' for a particular child, let alone every child.
Instead, it might be important to first focus on the 'ingredients of life' such as good nutrition, plenty of activity and skills building, strong social relationships and regular and sufficient sleep.
After that, the role of technology in relaxation, learning and connection might be easier to see.
Using technology to support healthy childhoods
Researchers are trying to understand the role of technology in a healthy childhood.
Scientists are studying the way sleep changes across the early years, and the major family and social factors that interact with sleep, so that they can explain to parents and carers what to expect.
They are examining family routines at home in great detail to understand exactly what is happening in the hours before bedtime.
For example, technology could be used as part of 'family time', it could be used alone or with siblings. Parents may find it relaxes their children or alternatively wakes them up.
Researchers are also looking very carefully at the type and timing of light emitted by digital devices used by children, in the context of the rest of their day.
While the light emitted by screens may be a concern, the role of bright artificial lighting in the home and other light sources such as TVs and street lighting also needs to be considered.
Parents and carers also need to think about light during the day: in the home, early education settings or at school. It is possible that some children aren't getting enough light at the right times.
The timing of light sends important signals to our bodies. We expect relatively bright days and dark nights. It is more common now to experience relatively dim days, with little outdoor light, and artificial lighting in the home or from the street extended well after sunset.
How technology can make kids' sleep worse
There are three main theories about the ways technology might make kids' sleep worse.
The first is increased exposure to light in the evening.
Most screens emit light and some devices are held quite close to our eyes.
Our internal body clocks, or circadian rhythms, more or less depend on bright days and dark nights to keep time. Light at night, even in small doses, can surprise this system.
Children have strong body clocks, but are also very sensitive to light.
The type of light emitted by devices, often quite blue light, seems especially powerful in its effects. This can lead to later sleep times, disruption of the body clock and increased risk of health problems.
The second theory is about displacement.
Using technology at night is an additional, and often very engaging, activity.
Spending time on screens makes it harder to fit in dinner, a bath, reading time or a regular bedtime wind-down routine. This can mean that sleep is pushed later just to fit everything else in.
This is hardly a new idea — it's likely today's parents were yesterday's children reading books by torchlight under the covers.
The third theory is about the conflict between the technology-based activity itself and the need to relax and drift off to sleep.
Some digital content can increase attention and focus. Some of it can be distressing, confusing or upsetting.
If this is happening in the hours before bedtime, then it is another signal to delay sleep time.
The challenge here is to measure and understand these emotional aspects of digital content, how it is used and how it is experienced by children.
How to help your kids get a better night's sleep
It's now understood that sleep is just as important as diet and exercise for children’s development and wellbeing.
And research has revealed some of the fundamentals of good sleep: a safe and secure bedroom environment, not too hot or cold, not too noisy, and nice and dark is a good starting point.
A regular wake-up time and a regular bedtime routine help set and reinforce our body clocks.
Researchers are also thinking of ways to use technology to help rather than hinder kids' sleep.
For example, technology could include alerts about bedtime and winding down time for children. It could suggest 'pro-sleep' content that isn't going to hype them up or upset them just before they need to fall asleep.
Technology could interact with smart homes and adjust lighting levels to reinforce sleep and wake times automatically.
It could also be used to connect networks of young 'sleep champions' together or it could involve new programs for children to learn, experiment and collaborate in developing better sleep habits.
There's never going to be a one-size-fits-all answer to helping our kids get a better night's sleep but there are things parents can do to help that don't involve ridding their homes of all digital devices.
Professor Simon Smith is a neuropsychologist and recognised expert in sleep and the developing brain. He leads the Community Sleep Health Group in the Child Health Research Centre at the University of Queensland and is also a chief investigator in the ARC Centre of Excellence for the Digital Child.
This research was supported in part by the ARC Centre of Excellence for the Digital Child. Professor Smith's work is also supported by the Australian Government through the ARC Centre of Excellence for Children and Families over the Life Course, the National Health and Medical Research Council (NHMRC) and the Medical Research Future Fund (MRFF).