And from a behaviorist point of view this is because of the associative history of these things.

在行为主义者看来,这是在这些事物之间的联结历史造成的。

耶鲁公开课 - 心理学导论课程节选

You use the "who" questions to ask about subjects, to ask who the subject is of the certain action or anything really.

当你要询问主体，即某一行为或事物的主体时，你可以用“who”问句。

Who 课堂 - SpeakingMax英语口语达人

So you're marching forward at that pace, but now as you get closer and closer to each other, various items begin to affect your behavior.

所以大家步调一致地突进,但当你越来越接近对方时,各种事物开始影响你的行为

耶鲁公开课 - 古希腊历史简介课程节选