The mouth moves up, particularly if somebody is attacking their record or ridiculing them, and they'll smile and--but it's not a sincere smile.

嘴唇移动，特别当有人攻击他们的记录,或嘲笑他们时，他们会微笑，但不是真诚的微笑。

耶鲁公开课 - 心理学导论课程节选