How Facial Expressions Demonstrate Evolution of Emotions

The eyes have it, as they say. Well, at least that's what Cornell University neuroscientists believe, when it comes to how our faces govern certain expressions depending on varying emotional situations.

For instance, have you ever wondered why your eyes widen when you're afraid or they squint when you're disgusted or angry? Emotional responses are the simple answer.

As our eyes widen to a fear evoking responses, sensitivity cells are also boosted to expand our field of vision and locate surrounding areas of danger. The opposite is true when we're disgusted. Our eyes narrow, blocking out light to sharpen focus and pinpoint the source our disgust.

"These opposing functions of eye widening and narrowing, which mirror that of pupil dilation and constriction might be the primitive origins for the expressive capacity of the face," said study author Adam Anderson, via a press release. "And these actions are not likely restricted to disgust and fear, as we know that these movements play a large part in how perhaps all expressions differ, including surprise, anger and even happiness."

Anderson further explains that facial expressions are actually caused by pupil dilation and constriction. He adds that the widening and narrowing of the eyes are not linked exclusively to feelings of fear or disgust-but more to certain movements and how they're limited to certain emotions, including anger, joy, shock and/or sorrow.

As he takes the findings a step further, Anderson notes that he hopes to study how facial expressions have shaped the evolution of nonverbal communication.

What do you think?

More information regarding the study can be found via the journal Psychological Science.