Your mother's smile

摘要

Charles Darwin once noted that he had no great quickness of apprehension nor wit, nor power to follow a long and purely abstract train of thought. What made him "superior to the common run of men" was his ability to notice things that can easily escape attention. Thirteen years after publishing "The Origin of Species", Darwin produced a lesser-known book in which he argued that animals, like people, feel emotions and express them using their faces. Humans, he thought, were not alone in opening their mouths when listening, pursing their lips when concentrating or touching faces with loved ones.