i think that BR told not about emotional doubts. That mean that emotional doubts are not about BR told. "Emotional doubts" are not ever real doubts.
For example doubts of jealousy based not on disbelief in love(for example), not on the reaction on assumed partner's flirt. That mean that doubts begets emotional statuses or ect. and other fantasies about unfaithfulness. Not said words to another begets distrust, but doubts(in something foundation) begets distrusting view point that supported by emotions. Lots of emotions beget the affect status, when doubting person doesn't able to see what directly calls the doubt effect - because emotional hormones(emotional statuses) they deprive him of the opportunity to soberly assess
situation.
Also a man may has calm doubts, with low emotions, but it is still can be hard to find their cause. For example to doubt that the God is exist. Someone is not crying about it, but has self doubt. Or crying, but not always, sometimes he is calm, but still in doubts, maybe more then in crying.
*and here you are close to answer a question what are emotions and why are you use them, and why BR relied on them less then nowaday humans do.