Slaves of the Slave System Plantation agriculture was wasteful, largely because King Cotton and his money-hungry subjects despoiled the good earth; quick profits led to excessive cultivation, or âland butchery,â which in turn caused a heavy leakage of population to the West and NW.
It means that since most adults need 8-9 hours of sleep, they will need about 1.6-1.8 hours of deep sleep to feel fully functional next day. However, the time of deep sleep is changed and that's mainly due to the change in the sleep need of different group of people. For instance: Age Group.
Most deep sleep occurs during the first two sleep cycles, with the greatest amount of deep sleep typically occurring in the first cycle. As the night progresses, deep sleep decreases and is replaced by the lighter stage 2 sleep and there is an increasing amount of REM sleep toward morning.