First, I want to talk a little bit about facial expressions, which are ways in which we communicate our emotions not the only way, but an important way and look, in particular, at the case of smiling because it's kind of interesting.

首先，我要讲一点面部表情，这是我们在情感中的交流方式,不是唯一方式，但是重要的方式,看，特别是，拿微笑为例,这有点有趣。

耶鲁公开课 - 心理学导论课程节选