You really do need your beauty sleep, study finds

You know the drill: You haven’t had a good night’s sleep for a few days and now you don’t like what you see in the mirror — puffy eyelids, dark circles, sallow skin.

You splash some water on your face and hope no one notices. Besides, it doesn’t really matter if you look tired, you tell yourself. It’s not like anyone is going to notice, right? Wrong. It turns out that just two consecutive nights of poor sleep can make you appear less attractive to others and, even worse, make them less interested in hanging out with you, according to a study in Royal Society Open Science.

“People seem to be able to tell when someone needs more sleep, and are more inclined to leave them alone in that case,” the authors wrote in the new work.

To come to this conclusion the researchers recruited 25 volunteers who agreed to deliberately limit their sleep for the good of science.

Members of this group, referred to as “subjects” in the paper, had their photo taken twice — once after two consecutive nights of normal sleep (about 7 1/2 hours) and again after two consecutive nights of poor sleep (about 4 1/4 hours).

In both sets of pictures the subjects were photographed in a grey T-shirt, with their hair pulled away from their faces, and were told not to wear makeup.

Next, the researchers showed the photos to a different set of 122 volunteers they called “raters.” These people were asked to rate the subjects on attractiveness, health, sleepiness and trustworthiness.

They also were asked how much they would like to socialize with the person in the photo.

The study authors found that overall, raters were less willing to socialize with tired-looking subjects compared with those who were well rested.

In addition, they also deemed the poorly rested subjects to be less attractive, less healthy and more sleepy compared with when they were well rested.

“Telling someone they look tired says more about your perception of them than you might think,” the authors wrote.

The study did not address the reason that a lack of sleep makes others want to avoid you, but the authors have a hypothesis. They explain that blood flow to the skin is strongly promoted by sleep. Perhaps when we don’t get enough sleep, that results in restricted blood flow to the skin, which in turn would make us look more pale and tired.