Beauty sleep is when:
1- you sleep before midnight
2- any extra sleep
John Axelsson from the Karolinska Institute in Sweden and colleagues studied 23 subjects ages 18 to 31. They were photographed between 2 p.m. and 3 p.m. on two occasions -- once after getting a normal night's sleep of eight hours and once after being up for 31 hours after getting only about five hours sleep.
The photographs were taken in a brightly lit room and the distance to the camera was the same in all the photos. No one wore make-up. Everyone had their hair loose, and were equally well washed and shaved between photos. The researchers asked them to have a relaxed, neutral facial expression for both pictures.
Sixty-five observers, who knew nothing about how much sleep each person had gotten, rated the photographs for attractiveness and whether the individuals looked healthy or unhealthy or tired or not tired. The observers judged the faces of sleep-deprived participants as less healthy and less attractive.
"Our findings show that sleep-deprived people appear less healthy, less attractive and more tired compared with when they are well rested," the researchers wrote in a paper published in the BMJ, a British medical journal. "This suggests that humans are sensitive to sleep-related facial cues, with potential implications for social and clinical judgments and behavior."
