New research suggests there may be a reason for the wide-eyed expression that often accompanies the perception of a fearful event.
Researchers believe the facial characteristics may enlarge our visual field and mutually enhance others’ ability to locate threats.
Daniel Lee of the University of Toronto and advisor Adam Anderson, Ph.D., believe that wide-eyed expressions of fear are functional in ways that directly benefit both the person who makes the expression and the person who observes it. The study is published in Psychological Science.
Research findings show that widened eyes provide a wider visual field, which can help us to locate potential threats in our environment. The widened eyes also help to send a clearer gaze signal telling observers to “look there,” which may enhance their ability to locate the same threat, as well.
“Emotional expressions look the way they do for a reason,” said Lee. “They are socially useful now for communicating emotional states, but this new research suggests that they were also useful as raw physical signals.”
Investigators found that participants who made wide-eyed fear expressions were able to discriminate visual patterns farther out in their peripheral vision than were participants who made neutral expressions or expressions of disgust.
In addition to the personal benefits conveyed by the facial expression, researchers found that onlookers could tell something was amiss because as eyes become wider, more of the whites of the eyes — known as sclera — is visible.
Lee and colleagues hypothesized that this could increase the contrast with the irises that signal the gaze, making it easier to tell where someone is looking.
Indeed, their data revealed that iris display and higher iris-to-sclera contrast were correlated with faster response times.
Lee believes that this research demonstrates just how social we are wired to be: “Our ability to process other people’s eye gaze is already finely-tuned; the fact that this processing is further enhanced by expressive eye widening underscores the importance of our eyes as social signals.”