And it turns out that there's a correlation, a reliable relationship between how happy somebody is now and back thirty years ago in their yearbook photo-- what sort of smile they're giving.

事实证明有相关性，可靠的关系,现在很开心的关系，30年后也是,在他们的年鉴照片里-,他们给出的微笑类型。

耶鲁公开课 - 心理学导论课程节选