In the end, I think we know the main factors that affect stuttering, including emotional ones. But often this is explained vaguely: "Emotions affect stuttering," but how? This is a theory that aims to explain how emotional aspects occur and affect the basic mechanisms of stuttering, and this opens up implications for the treatment of stuttering, and it matches with some evidences we have. Of course, it had to be somehow tested in stuttering cases, which is hard because the use of aversive stimuli (which cause negative emotions) is no longer ethical in research. I had never heard anyone explain it this way, until I came across with these authors that went deep in the emotional mechanisms of stuttering.