translation.en: But there's also a scientific reason that drove this project, which was to use this natural longitudinal data to understand the process of how a child learns language -- that child being my son.
translation.zh: 而促使这个项目还有一个科学的原因 便是用这些纵向记录的数据 去了解一个 孩子是怎样学习语言的-- 这个孩子是我的儿子