The next time someone tells you that you need your 8 hours you can emphatically tell them it’s up to your genes. It seems your genetic makeup and how you feel through the day has more to do with it than any old wise saying.
The US National Sleep Foundation suggests seven to nine hours a night is advisable for adults, and a survey it conducted in 2002 suggested three-quarters of Americans had problems sleeping and a third were so sleepy during the day their activities were affected.