User: Why did humans evolve to see so many emotions and expressions in each other's eyes?
Assistant: The complex facial expressions and signaling of emotions in human eyes has evolved as a social interactional and bonding mechanism, as it allows us to deeply understand and see the emotional state of other people as they communicate their feelings. Many early anatomists and neuroscientists think that we began developing these complex emotions and expressions of relatedness as human ancestors and evolved for social communication, and also that these "emotional signals" in the eyes are a uniquely human expression in comparison to other animal signals and behaviors. In modern social life and interactions with others, our emotional communication in the eyes and facial expressions are signs of empathy, understanding and connection.