Human beings are the only species who cry for emotional reasons. We weep at tragedies both in our own lives and in the lives of others–remarkably, we even cry over fictional characters in film, opera, novels, and theatre. But why is weeping unique to humanity? What is different about the structure of our brains that sets us apart from all other animals? When on our evolutionary journey did we first recognize the tragedy of life? When did our early ancestors first cry?
