What happens is, in the course of a single generation, they develop their own language.

实际情况是,在一代人的时间里,他们创造出了属于自己的语言

耶鲁公开课 - 心理学导论课程节选

Well, early on children start off and they prefer the melody of their own language.

儿童在出生早期,喜欢他们自己语言的旋律

耶鲁公开课 - 心理学导论课程节选