Drayna says the GNPTAB gene is present in all higher-order animals and contributes to humans' unique ability to communicate.

VOA: standard.2010.02.11

In order to communicate better about fear or not liking something.

这样你就可以更好地表达恐惧或者对某事的厌恶了。

I'm afraid of 课堂 - SpeakingMax英语口语达人