When searching, I find everyone referencing the two-sleep information - much based on Roger Ekirch. https://www.sciencealert.com/humans-used-to-sleep-in-two-sh

When searching, I find everyone referencing the two-sleep information - much based on Roger Ekirch. https://www.sciencealert.com/humans-used-to-sleep-in-two-shifts-maybe-we-should-again https://www.sciencealert.com/humans-used-to-sleep-in-two-shi... https://www.discovermagazine.com/health/dont-worry-if-you-cant-sleep-through-the-night-for-thousands-of-years-humans https://www.discovermagazine.com/health/dont-worry-if-you-ca... However, I did find this article from The Atlantic: https://archive.is/MYcgm#selection-1033.0-1049.105 https://archive.is/MYcgm#selection-1033.0-1049.105 >But humans have never had a universal method of slumber. A 2015 study of hunter-gatherer societies in Tanzania, Namibia, and Bolivia found that most foragers enjoyed one long sleep. Two years later, another study found that a rural society in Madagascar practiced segmented sleep. Two years after that, a study found that the indigenous residents of Tanna, in the South Pacific, largely had one uninterrupted sleep.