ICS Post-Doc Dr. Daniel Lee's recent paper "Reading What the Mind Thinks From How the Eye Sees" focuses on facial expressions, what they mean, and where they come from. Dr. Lee points out how the eyes escpecially play a crucial role. “We found that the most important dimension for reading the eyes is how wide open they are or how narrow they are.”
In a CU Boulder Today article, Lee (pictured right demonstrating several facial expressions) suggests that "widened or squinted eyes (and the raised or furrowed brows that often come with them) originated as much more than social cues. In fact, they probably helped the human race survive."
Read more at CU Boulder Today and watch the interview with Dr. Lee below: