"Mirror Image? When scientists showed monkeys these computer-generated images of monkeys, they found a negative response similar to what humans experience when viewing realistic-looking robots and computer avatars. Monkeys, they found, also are unsettled by images that are realistic but synthetic, a response known as the "uncanny valley" effect. The uncanny valley hypothesis refers to a dip in a graph that charts a human's positive reaction in response to an image on one axis and a robot's human-likeness on another. People, it seems, like to study other human faces, and they can enjoy looking at faces that clearly are not human, like a doll or a cartoon figure. But images that appear close to human but clearly are not cause a feeling of revulsion."