Napping and Brain Development

Why do some children stop napping before others?

New research suggests that transition out of napping may have to do with brain development, not age.  

The research focused on the hippocampus, which is the memory area of the brain.

When little children nap, they “consolidate emotional and declarative [conscious recollection of facts and events] memories…”  Dr. Rebecca Spencer, lead author of the study.

So, if they are doing this very important task, why would they transition out of napping if napping helps learning?  Why do some 3-year-olds no longer “need” a nap, but some 4–5-year-olds still do?

It’s about the brain.

The hippocampus is for short-term memory.

Memory, once processed, moves from the hippocampus to long-term memory in the cortex.  

  • The hippocampus is immature in young children, and can reach a limit to which how much can be processed without forgetting.  
  • When that limit is reached, children experience “sleep pressure.”  

Napping to the rescue.

Napping allows memories to be processed and to move to the cortex, which frees space for more information to be stored in the hippocampus.  

Researcher Dr. Spencer says to think of an immature hippocampus like a small bucket filling with memories.  If you have a small bucket, it’s going to fill faster and overflow–meaning some memories will “spill out” and be forgotten.  

Researchers think that children who still have an immature hippocampus still need naps, to allow the buckets to empty (move to cortex) faster and more frequently.

When the hippocampus is more developed, children can transition away from taking naps.  Their “bucket” has matured to the point that it will not overflow.  They can hold memories until the end of the day, when overnight sleeping can process the information and move it from the hippocampus to the cortex.

The takeaway

  • Age does not determine when children stop needing naps.  
  • Brain development is the determinant.
  • Napping shouldn’t be stopped based on age, but on need. Forced transitions out of napping could negatively affect learning.
  • These variations in hippocampus development are normal so no one with a 4-5 year old who still needs a nap should stress about it!
  • Continuing to offer the opportunity to nap to children who need it is important.


Press release: 

Study published in October 2022 paper in special sleep issue of Proceedings of the National Academy of Sciences.