Our happy hour to amaze you drinking buddies with.

Sleep-deprived people look less attractive.

Researchers at the Karolinska Institute in Sweden photographed 23 young adults after they had eight hours of sleep and again after they'd been kept up for 31 hours. The participants weren't allowed to drink alcohol 48 hours prior to the experiment, wore no makeup, were positioned an equal distance from the camera, and had the same expression in both photos.

Sixty-five observers were then asked to rate the two pictures. The sleep-deprived were consistently tagged as less attractive and less healthy-looking than the well-rested, confirming the concept of "beauty sleep," something that had never actually been scientifically tested.

Proven or not, we wish folks would also start to use the phrase "handsome sleep."