There really is such a thing as beauty sleep - and people who don't get enough of it do appear less attractive to others.
The experiment The researchers asked 25 university students, some male and some female, to be the guinea pigs in their sleep experiment. Each person was given a kit to check how much they slept through the night and was instructed to monitor two good nights of sleep (sleeping 7-9 hours) and two bad nights of sleep (sleeping no longer than 4 hours max). The group also said they'd be less likely to socialize with the students who got less sleep.
Next, the researchers recruited 122 adults - referred to as "raters" - and asked them view each photograph.
Researchers say that just 2 nights of sleep deprivation can make one appear less attractive.
As for trustworthiness, the respondents displayed no difference in attitude, the study noted.
The team, lead by Dr Tina Sundelin, found that strangers were good at assessing how exhausted a person was, and that they rated the sleepy set of photographs as less attractive than the photos of the same people when they were well-rested. In other words, people don't want to hang around with people who might be ill, whereas someone who looks energetic and fit will hold lots of appeal.
"Telling someone they look exhausted says more about your perception of them than you might think", the study starts. However, plenty of people fall short of getting as much sleep as they need - Gallup reports that 42 percent of adults in the USA don't get enough shut-eye. "Most people can cope just fine if they miss out on a bit of sleep now and again". Because we've evolved to try to avoid diseases, seeing an unhealthy-looking face makes us want to avoid that person.
You already know that a good night's sleep and weight loss have a strong correlation, but now studies officially show that there's a connection between shut-eye and perceived attractiveness.
"The reasons for avoiding people who look sleepy may include the fact that sleepy individuals are at a higher risk for accidents, more prone to be carriers of contagious pathogens or aspects making them less socially rewarding to be around". As it turns out, not getting enough sleep made participants score worse on all counts.