The opener of this article references the 7 hours of sleep figure for hunter gatherers which is from a quality study using sleep tracking devices [1]. But please note that’s actual sleep: you may need to be in bed for 8-9 hours to get 7 hours of sleep. When I used the Oura ring to track sleep I realized I usually overestimated my sleep time by discounting time to fall asleep and any time from being woke up at night.

The article states:

> By contrast, a 2016 study of almost 500 people in Chicago found they spent nearly all of their time in bed actually asleep

I think this is a poor summary: when I look at the study cited, it looks like the participants are awake in bed for an average of 50 minutes.

[1] https://www.cell.com/current-biology/fulltext/S0960-9822(15)...