There are studies and then some interpretations. These interpretations might not be true and real.
According to a few other studies, human being is supposed to wake up every 4-6 hours. At some point, it was normal for a person to wake up in the middle of the night and go to his neighbors and play cards or something.
Waking up for a couple of hours and then go back to sleep until the morning is supposed to be normal. There was even a name for the second sleep it was called “Dorveille“. Google it.
When left to themselves without any pressure of any kind, human beings will revert back to that sleep pattern.
How do you measure success? For me, success has nothing to do with money or fame it has to do with happiness, the lack of care of suffering. In other words, the less you care about suffering the more you are happy.
That is my definition of happiness. In their study, there are using their own definition, which is more aligned with the consensus.
>>> “As you might guess, it’s better for the brain to sleep for a shorter number of uninterrupted hours than a longer number of fitful ones.”