Facial expressions explained by Cornell study that shows the evolutionary benefits of the most noticeable human emotional response. Researchers led by Adam Anderson built a model of the human eye and then an apparatus that restricted and increased the amount of light let into the eye in a similar way that the eyelids do when they open and close to convey emotions. When scared or surprised, eyes tend to open wide, this allows in more light and increases peripheral vision. This raises the chance to spot dangers in a wider field of view, helping to avoid predators and other dangers. Conversely, anger and disgust cause the eyes to squint, reducing the amount of light let into the eye and allowing for a sharper focus on objects and creatures directly ahead.
The effect facial expressions have on the eye sheds light on why cultures around the world express emotions in the same way. It is readily apparent how someone is feeling by just looking at their face, regardless of where they are from. In another portion of the tests conducted by Anderson, volunteers were instructed to form various facial expressions ranging from happiness to disgust while they looked through standard optometry equipment. Tracking the pupils of the subjects and the amount of light entering their eyes during each expression showed the effects that each emotional response had on the brain.
Perhaps even more interesting however, was that the data of this test suggested that emotions play a strong role in how people see different situations, rather than the situation determining how people feel about it. Anderson believes that the differing effects of levels of light entering the eye during different emotional responses was a key component in the way that emotions evolved through the centuries as people dealt with constantly changing and shifting events. With facial expressions explained by the Cornell study, Anderson is now working on figuring out the effects nonverbal communication has on the emotional responses people have during conversations.
The connection between expressions and emotions comes down to the similar effects between partially closing the eyes and opening them wide and the contraction and expansion of the pupil, respectively. There is also evidence that the shape of our faces had an effect on our ability to communicate via nonverbal means, as prey animals such as deer and rabbit usually have eyes on the sides of their head compared with predator species such as cats and wolves (and humans) having eyes on the front of their heads. The difference is that prey animals have a wider field of view to make it easier to watch out for predators, but their nonverbal communication tends to come from the rest of their body and the way they carry themselves.
Predators on the other hand, benefit from stereoscopic vision, making it easier to see where a target is in three dimensions and strike at it quickly. As a bonus, both eyes being on the same plane of the face allows members of a species to easily determine how another feels by simply observing their face, especially the state of the eyes. Having facial expressions explained by the Cornel study opens the door further understanding how our ancestors worked together and communicated through the ages.
By Daniel O’Brien