Infants are polyphasic sleepers with wake-sleep cycles every 2 hours due to feeding needs and an underdeveloped circadian clock.

“why do you do that why can't you just simply be born and sleep in a monophasic way it's for at least two reasons first an infant needs to feed every two hours so their energy needs and their food intake requirements dictate that you can't sleep for very long because you need to be awake to feed and then you go back to sleep Within probably the first six months things will start to to change a little bit but the second reason that you are highly polyphasic when you are first born is because your super chiasmatic nucleus and in another episode we spoke about this Central master 24-hour clock that beats out your Cadian Rhythm the rise and the fall the wake and the sleep that has not yet developed it hasn't been glued into place into the brain this 24-hour clock so the infant seemingly knows nothing about when it's light or when it's dark outside that just awake or sleep awake a sleeve so that's the second reason energy feeding needs is the first and then an absence of yet a fully developed 24-hour clock in the brain to beat out that beautiful dictated Rhythm”

“so now we've switched from polyphasic sleep as infants to basic sleep as kindergarten could you describe that it was basic patterns I recall in kindergarten um having nap time in the afternoon yeah they put out these little mats and every every kid would just kind like roll up it's actually sounds really nice it's one you know wouldn't and we'll speak about how some adults do this too but almost every kindergarten system that I've inquired about around the world different nations they all have this nap time and Any teacher will tell you if one of those children does not nap during that period of time they are the Loose Canon they are the live wire and in subsequent episodes we'll speak about exactly how sleep harnesses and improves our emotional and mental health and how it falls apart when we don't so that that's how it certainly is emerging biologically and that's how we as a society respect that and accommodate that and then probably by the age of starting school so sort of five or six now we're starting to see fully monophasic sleep children sleeping long bouts at night and then being able to sustain wakefulness during the day at that point you have locked in your monophasic pattern and that will continue throughout adulthood and into old age with a few caveats that we'll speak about so that's how sleep sleep unfolds in the monophasic biphasic polyphasic sleep across the lifespan”