Scientists discover why some thrive on less sleep than others

Researchers at the American Academy of Sleep Medicine conducted a study to find out why a small percentage of people appear to only need six hours of sleep whereas most everyone else needs between eight and nine hours for optimal functioning during the day. They worked with 100 pairs of twins and identified a gene mutation that allows one not only to function on less sleep but also to experience fewer effects of sleep deprivation even after an all-nighter. Cognitive performance was measured every two hours during the sleep deprivation period by means of the Psychomotor Vigilance Test. After this period of extended sleep deprivation, the twin without the variant slept for 9.5 hours while his brother or sister slept just eight hours to catch up.