This Mood Meter display is counting smiles in MIT's Media Lab building. Susannah F. Locke

The great MIT Mood Meter claims to know all your hopes, dreams and fears. Well, perhaps not. But it can count the number of smiles in a given area, giving some kind of indicator of mood expression.

The Mood Meter came about when a team of researchers at the place from whence all awesome things come, MIT’s Media Lab, hooked up a camera and screen (or projector) to some nifty facial recognition algorithms that can spot faces and smiles in real time. And, after assuring campus security that they wouldn’t be recording any images, they placed the installations in four different locations across MIT’s campus.

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Faces deemed to be smiling are augmented on the screen with a big, cartoon smiley face. Frowning and neutral countenances get an emotionless overlay, instead. The software also estimates how big each person’s smile is, on a scale of 0 to 100, and averages the expressions into a happiness barometer rating for the area. It certainly encourages people to try smiling, as you can see in this video.

The researchers think that the tech could be used to help public speakers and comedians better connect with their audiences.


The Mood Meter website shows a live heat map of campus smiles in four locations around MIT.

Facial Recognition

Here, the facial recognition algorithm doesn’t pick up the face in the middle, obscured by a hand.


Some people left smiley face images on the sofa during one of the weekends, which the system picked up as real, smiling faces.

This Dog Ain’t Smiling

The Mood Meter can recognize at least some animal faces, too.

Mood Meter Live

The MIT Mood Meter in action on campus.

When You Smile

This Mood Meter display is counting smiles in MIT’s Media Lab building.

Smile Like You Mean It

PopSci editor Susannah F. Locke is only smiling about a 5% smile in this picture, but she can assure you that it recognized her true, winning grin.