Could science be on the edge of a breakthrough discovery about your toddler?

Researchers of a recent study found a significant drop in REM sleep occurring in children at around 2.4 years of age. Although it’s not yet known why REM sleep exists in the first place, this study could be an important step towards a new discovery.

Non-REM sleep is assumed to be the sleep phase where our brains essentially tidy up. Although no definitive reason has been found for REM sleep to exist, we think it has to do with the brain reorganizing information. 

The study in question found that between 2 and 3 years of age, children go through a sleep developmental stage that causes this sudden drop in overall REM sleep time. Although researchers tried to see if the same drop occurs in other mammals, nothing noteworthy has been found. Regardless, this new data could tell us something interesting about humans and sleep and importantly, the purpose of REM. 

Meanwhile, it’s interesting to me (and I’m sure other parents) that the “terrible twos” appear to line up with this developmental stage in our children’s sleep. Like many baby stages before it, the toddler period clearly shows some changes that we, as parents, need to pivot for yet again. I wonder if as the reason for this phenomenon becomes clear, we might simultaneously discover more information about the way our 2- and 3-year-olds are experiencing the world, and how their sleep might be improved during this period. 

Of course, good things take time and the answer isn’t there yet, so while we’re waiting, here’s what science can already tell us about our 2-year-old’s sleep needs:

• In the course of 24 hours, most 2-year-olds need 12 hours total of sleep. Most 3-year-old need 11 hours total.
• After 3 years old, you’re heading towards phasing out daytime naps. If your child is resisting bedtime, removing naps might be your answer.
• Routine, routine, routine. By now, your child has entrained their system to become reliant on their routine. Maintaining more or less consistent wake, eat, play, and sleep times daily will make that strong entrainment a positive thing
• If your toddler is getting up too early, go into their room at their undesirable wake time and find the light. Daylight is what's most likely waking them up. Cover up the intruding light with a blackout curtain, or by removing any artificial lights, and after a few days your child’s wake time should become more reasonable.