I meant the expectation of how much to sleep. It's often claimed that in the past people slept much more, but hunter gatherers actually sleep on average 6.5 hou

I meant the expectation of how much to sleep. It's often claimed that in the past people slept much more, but hunter gatherers actually sleep on average 6.5 hours a night. http://www.bbc.com/future/story/20170220-the-surprising-truth-about-why-we-sleep-and-how-much-we-need http://www.bbc.com/future/story/20170220-the-surprising-trut...