Different in degree or kind: we sleep less (Introduction)

by David Turell , Monday, January 25, 2016, 15:38 (3225 days ago) @ David Turell

We get less, but deeper sleep than all other animals:-http://www.bbc.com/earth/story/20160121-the-strangest-thing-about-human-sleep-is-that-we-need-so-little-"Most of us sleep between six to nine hours a night, meaning we spend about a third of our lives asleep. This may seem like a long time, but we actually sleep the least among all the primates - the group that includes monkeys, apes and us.-"So says a new analysis looking at the impact sleep has had on our evolution. The new research suggests that humans have evolved to sleep less, but also to sleep very deeply. This may help explain our success as a species.-***-"The theory goes that although we sleep for fewer hours than other primates, the sleep that we have is of high quality so we do not need as much.-***-"To understand whether human sleep is unique, Samson and Nunn compared the sleep patterns of 21 primates, whose slumber patterns had already been analysed.-"As well as noting how long the animals slept for, they looked at how much time they spent in rapid-eye movement (REM) sleep. This is when we dream, and when our brain consolidates our memories into long-term storage.-"Humans slept the least. The sleepiest primates were grey mouse lemurs and night monkeys, which slept for 15 and 17 hours respectively.-"But in contrast, humans spent the highest proportion of their sleep in an REM state: almost 25%. "Humans therefore have the deepest sleep of any primate," says Samson.-"Humans therefore have the deepest sleep of any primate"-Comment: We are very different in every way.