Emotions act as a kind of currency passed from person to person; confronted with a wealth of joy, we feel our own mood shift upward. How exactly does this social response work? We unconsciously mimic others’ facial expressions to create the same emotion in ourselves, a new University of Wisconsin study suggests.This complex process not only transpires in mere moments but it is actually an evolutionary mechanism, the researchers say, one that helps us respond to other people and the social environment appropriately.

According to Dr Paul Ekman's well-known theory, we possess just six universally recognized emotions: Happiness, sadness, fear, anger, surprise, and disgust. Though recent research has challenged this view by suggesting there are only four basic emotions, many scientists, including the team behind the current study, believe emotions evolved to help us adapt and respond to our environment.

“I think when people hear words like ‘adaptation’ or ‘evolved’ they think this must mean that the behavior (in this case, emotions), must be reflexive or highly genetically predetermined — but in fact, we evolved emotions so that our behaviors could be more flexible and dynamic,” Adrienne Wood, a psychology graduate student, told Medical Daily in an email.

Explaining this evolutionary theory, she says emotions are brain and body states that prepare and drive us to respond to events in our environment. Particular emotions, such as anger or fear, may be linked to behavioral tendencies, such as aggression or fleeing, but the behaviors are not formulaic and unchanging. In other words, specific emotions are not hardwired to automatic behaviors, instead they work as “a motivational state that drives us to achieve a particular result, such as escaping a terrifying situation, but lets us have flexibility in how we accomplish that result,” Wood says.

If emotions are motivational, what can we make of our human tendency to unconsciously mimic other’s emotions?

Part of the Whole

Wood and her colleagues hypothesize mimicry helps us interpret emotion in order to gain useful information about the social environment and respond accordingly.

While intense emotion is easy to recognize even at a distance — it’s easy to see and interpret wide-eyed fear, for example — most facial expressions are subtle, fleeting, idiosyncratic, and communicated by ever-so-slight changes in eyebrow position, head tilt, or lip press, according to the researchers. Yet “emotion systems” are organized in such a way that activating one component in the total system will automatically activate other components, the researchers say.

In real-time, then, what happens is this: Talking with a friend, we unthinkingly copy just one small part of his facial expression (the way he lifts his eyebrows, say), and this small motion activates an entire emotion system located in the motor and somatosensory cortices of our brain, and then feeling what our friend feels, we respond appropriately.

Proof of this, Wood says, can be found in studies that demonstrate people who are unable to mirror another person's face are limited in their ability to read and properly react to others. For instance, social disorders, like autism, are associated with mimicry impairments. Another example is a recent study linking facial mimicry deficits, caused by (of all things) pacifier use in early childhood, to deficits in emotional competence. The longer the boys had used a pacifier, the “less spontaneous facial mimicry they displayed and the lower their scores on measures of empathy and emotional intelligence years later,” wrote the authors. Yet, pacifier use did not impact the emotional competence of girls.

Shared Feeling

“We occasionally see gender differences in emotion processing and facial mimicry, and we think it can be explained by systematic differences in how boys and girls are socialized in our culture,” says Wood. “It could be the case that parents give pacifiers to boys and girls in different situations for different reasons, which could change how pacifier use alters emotion processing.” Finally, more evidence of the imitation game leading to real feeling is a common complaint of people with facial paralysis from a stroke or Bell's palsy — or even plastic surgery — is it interferes with their ability to recognize and "share" others' emotions.

Asked if regular everyday bad facial mimicry might lead to emotional misinterpretation, Wood replied, “Definitely… accurate emotion recognition depends on eye contact, a desire to know what the other person is feeling, and some understanding of the person and the context they are in.”

The team concludes a richer knowledge of the mechanisms underlying emotional mimicry or in their words, “sensorimotor simulation,” should lead to better treatments of related disorders. Still, what remains for Wood is a simple appreciation of our human complexity.

“Without emotions, we would not have anything in our brains telling us to seek out pleasure, to care for one another, to run away from danger, or to strive for our goals,” Wood said. “The adaptive purpose of our emotions is to make things in our lives meaningful.”

Source: Wood A, Rychlowska M, Korb S, Niedenthal P. Fashioning the Face: Sensorimotor Simulation Contributes to Facial Expression Recognition. Trends in Cognitive Sciences. 2016.