What Facial Expressions Are Really Saying
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It's MORNING EDITION from NPR News. I'm Steve Inskeep.
RENEE MONTAGNE, host:
And I'm Renee Montagne. Good morning. Coming up in Your Health today: protecting your feet. If they hurt we'll see it on your face. And the expression on somebody's face can tell a lot - if that person is bored, afraid, disgusted, happy, in pain. We go now to a story on how humans developed expressions in the first place. Michelle Trudeau tells us about a new study that explores this from the journal Nature Neuroscience.
MICHELLE TRUDEAU: Faces are what neuroscientists Adam Anderson and Joshua Susskind from the University of Toronto love to look at and think about and analyze. Here's Adam Anderson.
Mr. ADAM ANDERSON (University of Toronto): We were interested in exploring why facial expressions appear the way they do.
TRUDEAU: Why do people around the world in every culture ever studied have very similar facial expressions? Well, one reason was already well-known.
Mr. ANDERSON: Facial expressions are critical for social communication.
TRUDEAU: Lot's of research has shown that a look can speak volumes between two people. But how did facial expressions get started originally, and why? Why do they look they way they do?
Mr. ANDERSON: Why do people smile when they're happy? Why do they wrinkle their nose and raise their upper lip when they're disgusted? Why do they raise their eyebrows and lift their eyelids when they're afraid. Why these specific muscle actions?
TRUDEAU: They had a clue - a theory from a book published over 100 years ago by Charles Darwin. He suggested back in 1872 that facial expressions evolved so a person could quickly figure out what's going on, could read the environment, to be ready to take action. In other words, Darwin hypothesized making faces probably had some survival advantage.
Mr. ANDERSON: So he laid out some principles that really were inspirational to our work.
TRUDEAU: To test Darwin's survival theory, the researchers persuaded some university students to come into their lab and asked them to make two different facial expressions: fear and disgust. Fear and disgust faces are polar opposite expressions. So first the students made a fearful expression and the researchers measured all facial details.
Mr. ANDERSON: Trying fear expressions, one's visual field increases in size.
TRUDEAU: Meaning one's peripheral vision improved.
Mr. ANDERSON: And we measured the speed of eye movements.
TRUDEAU: And found...
Mr. ANDERSON: Those muscle actions enhanced or sped up your capacity to move to targets in your visual field.
TRUDEAU: And they measured nostril size and inhalation.
Mr. ANDERSON: Fear expressions enhance your capacity to take in air, both its velocity and the volume you can take in.
TRUDEAU: So a fear expression opens up, speeds up and increases sensory information about the environment. In contrast, an expression of disgust - a scrunched up face - does just the opposite. Disgust shuts our sensory information, the researchers found. You see and smell less.
Ms. ELIZABETH PHELPS (New York University): It makes perfect sense once someone points it out to you.
TRUDEAU: But nobody had every studied it before, says Elizabeth Phelps, a neuroscientist at NYU. That's what's so wonderful about this study. Finding a second reason besides social communication for facial expressions. They can save your life.
Ms. PHELPS: You're afraid of something, it may be kind of like, what's going on? What am I supposed to do here? So you want to take in more information to figure out how to react appropriately, so that's one function of what fear does to help survival.
TRUDEAU: So the next time you grimace or glare or scare, get thee to a mirror and see what Darwin saw, and now these modern researchers, too. Your facial expressions are there to serve and protect.
For NPR News, I'm Michelle Trudeau.
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