22 Interesting Facts You Didn’t Know About Sleep

How much do you know about sleep? Here are some interesting facts about sleep you might not have been aware of.
Quiz by islabonita
Last updated: June 13, 2019
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First submittedJune 13, 2019
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1. What percentage of people dream entirely in black and white?
Before color television was introduced, only 15% of people dreamed in color whilst older people dream in black and white more often than younger people.
2. What percentage of a cat’s life is spent asleep?
This will come as no surprise to most cat owners.
3. How many hours of sleep does a giraffe need in a day?
About 15 hours
About 2 hours
About 6 hours
4. Pain tolerance is reduced by sleep deprivation.
Cutting a person’s sleep in half dramatically reduces pain threshold although it’s not 100% clear why.
5. Islam dictates that people sleep...
on their backs
on their right sides
on their stomachs
on their left sides
Muhammad said, “Whenever you go to bed, perform ablution like that for the prayer, and lie on your right side”
6. Sleep experts have discovered a direct link between people’s favorite sleeping positions and their personalities.
This is also according to Professor Idzikowski, suggesting that those who sleep in the foetal position “may appear tough but are actually sensitive souls right to their core.”
7. Experts say Ideally, falling asleep at night should take you...
1-5 minutes
15-20 minutes
10-15 minutes
If it takes you less than five minutes, chances are you are sleep deprived.
8. Humans are the only mammals that willingly delay sleep.
9. Fear is the main emotion in nightmares.
Researchers have found that it’s most often feelings of sadness, guilt and confusion.
10. What sleep position is best for digestion?
Front Down
Front Up
Hands should apparently be positioned above the pillow so you’re in a ‘freefall’ position.
11. How many hours of sleep does a brown bat need in a day?
About 16 hours
About 10 hours
About 20 hours
12. How much of a human's life is spent in sleep?
About 33%
About 40%
About 20%
This obviously differs depending on the age of the human, but on average it’s around a third.
13. What is the record for the longest period without sleep for a human?
14 days
11 days
7.5 days
This was set by a Californian student named Randy Gardner in 1964. This is definitely not recommended, however, as Randy experienced extreme sleep deprivation and others have died staying awake for this long.
14. Some deaf people use sign language in their sleep.
There are many instances where people have reported their deaf partners or children using sign language in their sleep.
15. What is Dysania?
Sleeping with the eyes open
The fear of nightmares
The state of finding it hard to get out of bed in the morning
We’ve all no doubt found it tricky getting out of bed every now and again, but those suffering from Dysania find it particularly difficult. It is most likely to be a form of Chronic Fatigue Syndrome.
16. What is Parasomnia?
Giving birth during sleep
Unnatural movements during sleep
Not dreaming during sleep
Some people have even committed crime due to parasomnia, including sleep driving and even murder.
17. What are Hypnic Jerks?
Annoying people who won't let you sleep
The sensation of falling when half asleep and jerking yourself awake
Hiccuping while sleeping
No-one is totally sure why hypnic jerks occur but they are deemed to be perfectly healthy. However, they may be increased by anxiety, caffeine or physical activity close to bedtime. They are more frequent in young people and decrease as we get older.
18. What percentage of the population are sleepwalkers?
This is according to the National Sleep Foundation. It’s also a myth that you shouldn’t wake someone who is sleepwalking.
19. What percentage of married couples sleep in separate beds?
20. What will kill you quicker, sleep deprivation or food deprivation?
Sleep Deprivation
Food Deprivation
Neither are good for you, but sleep is actually more important than food in the short term.
21. Those born blind experience dreams involving things such as...
bright lights and colors rather than sight
dark greys, black and white shapes rather than sight
emotion, sound and smell rather than sight
This is a topic that is really quite interesting and the timing of the blindness in a person’s life may impact what that person dreams about.
22. Within 5 minutes of waking up, what percentage of a dream is forgotten?
After an additional 5 minutes, 90% of recollection is gone. Sigmund Freud believed this was because dreams represent our repressed thoughts and so our brain wants to get rid of them quickly. However, it’s much more likely due to our brains simply being used much more as soon as we’re awake and so we forget much of what we’ve dreamed about.
Level 78
Jun 14, 2019
Interesting and informative quiz
Level 45
Jun 14, 2019