Dr. Matt Walker

There was a great study done by a colleague of mine, Tina Sunderland, and working out in Sweden at the Karolinska.

And this again was one of those studies that I just thought was so genius.

And it was a two-part study.

They firstly took individuals and they sleep deprived them for a night or they allowed them to sleep well.

In fact, they went through both of those.

And after a full night of sleep or after a night of sleep deprivation, they went into a studio.

And they had the picture taken.

They had a portrait shot done under identical lighting conditions.

So now for every participant in the study, you've got two headshots.

One of when they were sleep deprived, one when they were sleep rested.

Great.

Now came the second part of the experiment.

They then took all of those kind of headshots and they recruited a new set of participants who acted as an independent set of judges.

And those judges knew nothing about the experimental conditions and the manipulations that had just happened.

They were simply shown these images, and they were asked to rate how attractive does this person look, how healthy does this person look, and how tired does this person look.

And again, they knew nothing about what was going on.

Sure enough, with very high statistical probability, when...

The headshot that was taken when they were underslept, they rated that individual as looking less attractive, as looking more sickly in terms of their appearance, and also looking more tired.

So first, they had proven this thing called beauty sleep, that you look a more attractive version of you when you are getting sufficient sleep.

But they also noticed this sickliness