7 points
i’m pretty confident it’s an evolutionary adaption to ensure there are people in the tribe that are wide awake when others are sleeping, to keep an eye on things.
same thing with neurodivergence, sexualities, and left-handedness; it’s all stuff that’s been boosting our survival as a species when a portion of the population has those differences.
5 points
3 points
People used to wake up in the middle of the night for a couple of hours then go back to sleep:
https://www.bbc.com/future/article/20220107-the-lost-medieval-habit-of-biphasic-sleep
