Computer system detects fake smiles

Humans have a facial expression that is known as a smile. According to the definition, it is an expression denoting pleasure, joy, happiness, or amusement. However, smiles can also be faked, or they can be an expression of anxiety; a smile then turns into a grimace. It is not always easy to distinguish between the two, especially if the person smiling is trying to hide something. A computer system developed by MIT is able to detect whether a person is smiling genuinely or tries to express his or her frustration. This helps to create computers that can assess the mood of the user, and act accordingly.

Experiment

Participants in the study were given a form to fill in or a video to watch, which was designed to cause frustration. They were also shown a video meant to induce genuine smiles. The scientists recorded the expressions on camera in both experiments. In addition, they asked the participants to provide them with a genuine and a frustrated smile, without anything that could influence their emotion. This, of course, helps to compare the smiles induced by emotion with voluntary smiles.

Results

Analysis showed that there were subtle differences between a frustrated smile and a genuine smile. Because the measurements relied on their actual emotions, after seeing the videos and filling in the form, participants had no real way of faking a smile. Indeed, when assessing the differences between the smiles that the participants gave after the scientists simply asked for it, subtle differences were found. They showed that their system can distinguish between a 'real' frustrated smile, and one that was only given because the researchers asked for it. 

Which one is real and which one is not? The one on the left is a genuine smile, while the one on the right is caused by frustration.

Outlook

A computerised system based on these findings could help to discover which smiles are genuine, those that are fake, and which ones are expressed due to frustration. This seems an especially useful tool in order to assess the behaviour of politicians, for obvious reasons. Additionally, the study provides us with knowledge about how human emotions work.