Imagine you’re grabbing lunch with a friend. You sit down to eat, when you notice your friend grimaces as they take a bite out of their sandwich.They don’t have to say anything for you to understand that something is wrong with their meal -- furthermore, you might even begin to feel a little sick yourself. Where does this complex nonverbal understanding of other people come from?
The Neuroscience of Facial Expressions
Neuroscientists have been fascinated by nonverbal bodily communication since Charles Darwin hypothesized that certain universal facial expressions existed across cultures. Since the late 1970s, ‘Universality Studies’ have identified seven basic emotions and their facial expressions, pictured below.
Evidence for this universality has been replicated across studies worldwide. One of the most compelling pieces of evidence is that blind individuals produce the same expressions when spontaneously prompted as sighted individuals. This implies that there is something innate about facial expressions, although they surely vary cross-culturally.
How does the brain interpret facial expressions? The answer lies heavily in the visual system. The occipital lobe, located at the back of the brain, contains an area known as the fusiform face area (FFA), a portion of the fusiform gyrus. The FFA interacts heavily with the amygdala, a region associated with strong emotional processing.
This loop is part of a greater neuronal network that connects to motor areas. The network, known as the AON or action observation network, is responsible for recognizing, decoding, and assigning facial expressions meaning.
More recently, researchers have isolated mirror neurons as a possible mechanism for facial emotion recognition. Mirror neurons fire both when an action is observed, and when an action is executed. In other words, they allow us to learn through imitation. It is likely that babies learn how to express themselves from watching their parents facial reactions.
These mirror neurons can fire consciously or unconsciously, using two different pathways. The pyramidal tract drives voluntary facial actions, while the extrapyramidal tract drives involuntary expressions. These involuntary expressions are known as microexpressions, and can last for as little as 1/70th of a second.
Recognizing microexpressions in others and controlling them for yourself can be the key to successfully navigating your work and personal life.
Cultural Differences and Training
Thankfully, training exists to improve individual’s recognition of microexpressions. Although programs like the METT (microexpression training tool) have recently come under scrutiny for their use in airport security , it is important to acknowledge that these skills are useful in less high-stakes circumstances.
One particular area where microexpression recognition can provide an important advantage is in cross-cultural communication. Sociologists have long recognized that culture can impact how people express their emotions. This phenomenon is known as display rules. These unspoken rules dictate how much emotion we can appropriately express in front of others.
In one key study, American and Japanese participants were asked to watch a distressing video alone. They both showed similar facial expressions of fear. When they were asked to watch the same footage with another person in the room, Japanese participants masked their initial reaction by smiling, while American participants continued to express their negative emotions.
Another interesting cultural difference in understanding facial expressions is how different people understand emotions in others. In other words, what kind of expressions are you used to seeing? Different cultures look to different areas of the human face to identify someone’s emotions.
Eye tracking studies have quantified this phenomenon. One study found that Americans predominantly look to the mouth or to the whole face to identify how someone’s feeling. On the other hand, Japanese people look at the eyes in particular.
This discrepancy is important to understand when you’re learning how to read people’s emotions better. Although there are seven universal facial expressions, a lot about understanding how people feel is about cultural context. Combining tonal clues, body language, and what you know about a person’s background can help you get a better understanding of what they’re saying -- and what they’re not saying.
Endres, Jennifer, and Anita Laidlaw. “Micro-Expression Recognition Training in Medical Students: A Pilot Study.” BMC Medical Education 9, no. 1 (July 20, 2009): 47. https://doi.org/10.1186/1472-6920-9-47.
Gaag, Christiaan van der, Ruud B. Minderaa, and Christian Keysers. “Facial Expressions: What the Mirror Neuron System Can and Cannot Tell Us.” Social Neuroscience 2, no. 3–4 (September 1, 2007): 179–222. https://doi.org/10.1080/17470910701376878.
Tipper, Christine, Giulia Signorini, and Scott Grafton. “Body Language in the Brain: Constructing Meaning from Expressive Movement.” Frontiers in Human Neuroscience, August 21, 2015. https://www.frontiersin.org/articles/10.3389/fnhum.2015.00450/full.