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.
In addition, the initial preponderance of deep or slow-wave sleep in early childhood decreases after puberty and continues to decline over one's lifespan. School-aged children (6-12 years of age) average approximately 10-11 hours of sleep in a 24-hour period. Research studies suggest that adolescents generally require about 9-9.25 hours of sleep per night ; however, many are getting less than 8 hours of sleep per school night.