Happiness is contagious, even in photographs.

SoulPancake, the YouTube channel you probably know from the Kid President series, launched a social experiment to put a smile on even more people's faces.

The channel built a giant Polaroid camera and placed it in the middle of the street. With "SNAP YOUR JOY" written on the camera in white, it asked people to come up and take pictures of themselves smiling.

If a prank channel were to set this up, we might see them just record people while they were under the impression that they were getting their picture taken. We don't know anything about the participants other than what they demonstrated in front of the camera, but they looked on with curiosity and excitement.

And since it's a Polaroid, after everyone snapped photos of themselves, the camera printed out photos of people expressing themselves for passersby to see.

And what they saw seemed to work: "I think that joy and positive emotions and happiness, they keep us going from day to day," one woman said.

H/T Viral Viral Videos | Photo via SoulPancake/YouTube