A person copies someone else’s smile or frown mainly because of the human instinct, which enables people to empathise with one another. The researchers explain that a person’s smile makes people feel better because they are unconsciously smiling with that person as well.

The research team says if someone finds a sad friend, then that person will try to put on that sad face, without being aware of it. This unconscious behaviour helps people recognise another’s feeling. Apparently, individuals can obtain the meaning of facial expressions in just a few hundred milliseconds.

“You reflect on your emotional feelings and then you generate some sort of recognition judgment, and the most important thing that results is that you take the appropriate action–you approach the person or you avoid the person,” says Paula Niedenthal, a social psychologist at the University of Wisconsin. “Your own emotional reaction to the face changes your perception of how you see the face, in such a way that provides you more information about what it means.”

Adrienne Wood

Adrienne Wood

The researchers note that a person will not be able to identify and share emotions when facial mimicry is not possible. This may result from simply using a pacifier for too long. People with facial paralysis from a stroke, Bell’s palsy or nerve damage from surgical procedures also experience this. However, those with congenital paralysis can compensate through other means to interpret human emotions.

Moreover, individuals with autism or other social disorders, linked with the inability to mimic or recognise emotions, also experience the same problems. The lack of facial mimicry of an autistic person may stem from avoiding eye contact. Hence, Niedenthal believes these people may be able to identify and share emotions from facial mimicry once they initiate eye contact.

The researchers aim to delve into the process that aids the brain to recognise facial expressions in their next study. This may lay the foundation where improved treatments of related disorders will be built upon.