Why Did Humans Evolve to Sleep 8 Hours When Predators Were Everywhere?
Humans evolved to need concentrated, high-quality sleep of roughly 6.5 to 8 hours because that window is when the brain executes its most critical maintenance operations: consolidating memories, clearing metabolic waste, regulating hormones, and processing emotional experiences through REM sleep. The predator problem was solved not by sleeping less, but by sleeping smarter in social […]










