Should children sleep during day time?

Many parents of infants are reluctant to let their children take daytime naps while in kindergarten. They are worried that the daytime naps will affect the night sleep. However, many studies suggest that (children/infants) should be allowed to sleep during daytime if they feel like it.

Sleep is of course essential for us to function properly. Even when we are sleeping, the brain is full of activity. When we sleep, the brain processes all the impressions it has received during the day. Memories worth remembering are reinforced and stored, while things not so important are erased.

Sleep is simply crucial for our ability to learn new things and remember them.

A study shows that this also goes for children in kindergarten. Children in a kindergarten, aged 3 to 5 years old, were to play with a computer game where they the goal was to remember items hidden behind some boxes. They could practice until they remembered 75% of the items. Then they were either allowed to take a midday nap, or was kept awake before they were tested again. The children who slept, remembered 10% more than the ones who stayed awake, and this difference was still there the following day. The night sleep did thus not reset the effect the midday nap had on their memory.

The same results were found in a similar experiment where the children had to name different animals on objects presented on a screen. They were then told to take a nap. When they woke up, the scientists tested their ability to recognise blurred pictures of the objects they recently had seen. A week later they repeated the experiment, but this time the children had to stay awake until their ability to recognise the blurred-out pictures was tested. The results were clear. The children recognised far more objects and animals when they had a nap, compared to when they had to stay awake.

It is also possible that lack of sleep during daytime, increases the stress level in the bodies of kids.

Because the level of the stress hormone cortisol increases in children when they don’t sleep. This was discovered by scientists from California by measuring the level of cortisol in children’s saliva. The cortisol level was measured in 54 children, aged 3 to 5 years old, where some were taking naps midday, while others were not. The measurements were taken between 1200 and 1500, in addition to the kids wearing ankle sensors detecting movement. The results showed that the kids who did not sleep during daytime, had increased levels of cortisol and more problematic behaviour than the kids who slept during daytime. These results are also supported by a previous study that found naps reduced the level of cortisol in toddlers.

How much sleep does toddlers and kids need?

Early in life the, babies spend more time asleep than awake, and by the age of 2, a baby has on average spent 9500 hours asleep and 8000 hours awake. The development of a stable sleeping patterns involves complicated biological mechanisms that are vulnerable to disturbances.  Until the child reaches the age of 5, the sleeping pattern goes through many changes. Gradually the child will sleep more during the night, and consequently require less sleep during the day. Sometime between the age of 3 and 5 they usually stop sleeping during the day time. A survey of the sleeping patterns of healthy children aged between 2 and 5, showed that they on average slept 55 minutes during daytime, and that this average became smaller the older they grew. It was also common that the naps happened irregularly, and not every day. One theory is that the brain reaches a new maturity level when kids no longer needs to sleep during the day time.

That is why we should not refuse our children their beloved day time naps until they are ready for it.

Sources:

1. Conversations with nursery staff in Oslo og Nittedal municipality
2.  Daytime Sleep Patterns in Preschool Children With Autism, Developmental Delay, and Typical Development. AJIDD, vol 116, s 142-152m 2011
3.  The Effect of a Daytime Nap on Priming and Recognition Tasks in Preschool Children. Sleep, vol 37, s 1087-1093
4. Nocturnal Sleep and Daytime Nap Behaviors in Relation to Salivary Cortisol Levels and Temperament in Preschool-Age Children Attending Child Care. Biological Reasearch Nursing, vol 9, no 3, s 244-253