It turns out, the concept of beauty sleep is not just clever marketing from cosmetics makers. According to a recent study published in the Royal Society Open Science Journal, not getting enough sleep makes you less attractive, less healthy and damages your social appeal.

The study discovered that sleep deprivation and looking tired not only have a direct relationship to health and attractiveness, but people are less likely to interact with someone who looks tired and unhealthy.

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Conducted at the Karolinska Institute in Sweden, researchers photographed 25 male and female students without makeup after they had slept for eight hours for two consecutive nights. The researchers took another set of photographs of the students after they restricted their sleep to four hours a night for two consecutive nights. Researchers presented each student’s photographs to a group of 122 strangers who rated each image in terms of attractiveness, health, sleepiness and trustworthiness.

Of course, most people gave lower scores to the people in the sleep-deprived images, labeling them as less attractive and less healthy. Raters admitted to being less inclined to socialize with sleep-deprived individuals, and the study goes so far as to suggest that people might avoid contact with a sleep-deprived person in order to reduce health risks.

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According to the study, "Having an unhealthy-looking face, whether due to sleep deprivation or otherwise, might thus activate disease-avoidance mechanisms in others and render one's surroundings less socially inclined.”

However, while the study found that people were found to be less attractive when lacking sleep, it discovered no change in other's perception of how trustworthy a person appears.