I'm not sure what you mean by that. Every assumption right or wrong comes from emotion. The problem tends to come when people let their emotions are left completely unchecked. "Bankers are taking advantage of me. My banker is an X minority. Therefore, we need to exterminate X minority" indeed has a nonzero degree of logic, but it's not the sort of reasoning 99% of people would come up with in a vacuum.

A counterpoint is that sometimes an irrational degree of emotion may be required to do extraordinary things like soldiers being brainwashed to fight even a defensive war, building a cathedral that fitting of the magnificence of god, or even a lot of cult-like startups.