Lots of variables to decide on how much sleep is enough, I would think. Alot like saying “2300 calories is all a person needs. Anymore and they will get fat”, is not an accurate statement. Take into consideration activity level, stress level, diet, current health, etc.
My personal experience is that quality of sleep is more important than quantity. I feel much more rested when I have consecutive nights of sleeping the whole night through 6-7 hours, as opposed to sleeping 4-5 hours, getting up to use the bathroom or whatever, then going back to sleep for another 4 or so.
What I don’t get is this. When they say one person sleeps 8 hours and another person sleeps 6 hours, is each person sleeping until they wake up naturally, or are they setting alarms and “forcing” themselves up?
What I’d like to know is whether someone who “naturally” wakes up after 6 hours if somehow healthier or somehow more likely to outlive someone who “naturally” wakes up after 8 or 9 hours.
When comparing a 6 hour sleeper to a 9 hour sleeper, are we comparing someone with a good job and family who only has time for 6 hours to an unemployed alcoholic who passes out for 9 hours at a time? I want them to control for other variables when reporting statistics like this! There is no way to read cause and effect into these stories.