Meaning of 気持ちを通わせていった


My question is about phrases like 心を通わせる, etc which use 通わせる. If I look up an
explanation using it I will often see e.g. 心が通じ合う which makes sense to me, but
I don't quite get how to understand the way the causative form of 通う is being
used.

こうして、流れに身を任せるように、お互いの **気持ちを通わせていった**




気持ちが通う：one's feeling interacts

人が気持ちを通わせる：People make their feelings interact

