Turns out there could be a scientific reason as to why your toddler will peacefully go down for a nap one day and then all of a sudden refuse naps altogether.
Unfortunately, there tends to be a time — generally when a toddler turns 4 or 5 — that all of a sudden, naps are not in their wiring. The idea of going down for a nap can cause a meltdown, and the small window that parents once had to catch their breath is gone. So why is a toddler fine with going down for a nap one day and the next they are done with napping forever? And why does it happen sooner for other toddlers than others? Researchers believe it has to do with the development of the toddler’s hippocampus.
A new study, led by Professor Rebecca Spencer, professor of psychological and brain sciences at University of Massachusetts, Amherst, takes a look why the transition from daily naps to a monophasic sleep cycle, or just sleeping for one long period daily, happens as kids age out of their toddler years.
Spencer, along with her co-author Tracy Riggins, a University of Maryland child psychologist specializing in memory development, combined their findings with the few already existing data on the topic to form a hypothesis: the development of the hippocampus, which regulates memory and storing new information, determines when a child no longer needs naps.
In early childhood, the hippocampus is in a rapid state of development. Spencer likened the structure of the brain to a bucket being filled with water. “When the hippocampus is inefficient, it’s like having a small bucket – your bucket is going to fill up faster and overflow, and some memories will spill out and be forgotten,” she explained. Taking a nap is a great way for toddlers to metaphorically empty the bucket so they can start retaining new information once again.
“That’s what we think happens with the kids that are still napping. Their hippocampus is less mature, and they need to empty that bucket more frequently,” Spencer explained. So as the hippocampus develops, there comes a time that it needs to be “emptied” less frequently — which is why a toddler might all of a sudden be completely over the whole nap thing.
Previous studies have shown a correlation between children taking naps and their ability to retain information. For example, in a 2020 study, Spencer found that children who napped after being read a new story retained more information about the plot and characters that children of the same age who did not nap.
Now, this isn’t to say that children who start refusing naps at the age of 3 are ahead of the development curve or that kids who still go down for a nap at age 6 are behind in any capacity. Different bodies need different levels of rest.
“Some of them still need it; others may not need it but if they take it, we know that it’s going to benefit their learning, and we know that learning is what underlies early education,” noted Spencer.
Whatever the age, it is completely normal for a toddler to age out of naps out of left field. Just one of the many (now data-backed) joys of parenthood.