Americans, it turns out, smile more than any other society on earth. In Japan, India, Iran, Argentina, South Korea, and the Maldives, smiling is viewed as dishonest, foolish, or both, according to a study by Polish psychologist Kuba Krys. Many societies believe that expressing happiness invites bad luck and is a sign of selfishness, shallowness, and an uninteresting, even sinister, mind.
