translation.en: Now everybody, young and old, finds the real laughs more contagious than the posed laughs, but as you get older, it all becomes less contagious to you.
translation.zh: 那么现在，所有人，无论老幼， 都觉得真笑比假笑更有感染力， 但随着年龄的增长，它们 都变得不那么有感染力了。