What made you laugh

    Would you like to know a language everyone in the world understands? You always do—because you laugh. Any two people from different cultures who don’t speak a word of the other’s language still know exactly what is meant when the other person laughs.
    Think of laughter as the unofficial language of the earth. Yet how much do any of us really understand about humor?
    Some biologists(生物学家) believe that laughter has more to do with fear than funniness. Early humans might have laughed once they realized that a threat—say, a saber-toothed tiger(剑齿虎)—had passed. Nothing was funny about nearly becoming lunch. The laughter escaped as their bodies’ way to ease tension(紧张). Though saber-toothed tigers may be long gone, laughing to relieve stress is not. 
    Levels of stress relate directly to health and wellness. Many people believe that laughter is the best medicine. Norman Cousins, an editor and professor, looked for common treatment for a painful disease but felt little improvement. Then he tried to heal himself by watching a lot of funny movies and TV shows and reading humor. Finally he said happily that laughing did help him recover(痊愈).