The theory does not say that emotions cause stuttering. That would imply that anyone emotionally affected enough could develop stuttering, and that’s not the case. The theory suggests that emotions are vectors through which the genetic condition necessary to develop stuttering manifests. And when I say emotions, I mean a deep understanding of what emotions are in the body, such as the activation of the sympathetic and parasympathetic systems, neurotransmitter disposition, and that kind of thing— the physiological aspects of emotions. It’s not just what you perceive in your own self-awareness and consciousness as "anxiety," but the entirety of events that happen in an emotional moment, including the physiological effects of emotions that we may not even perceive or be aware of. But indeed, there is no evidence for such a phenomenon in childhood as I described. In fact, there are not even mechanisms to verify these hypotheses, as there have been no ways to study emotions consistently in an observable or direct manner until now. But it is a very interesting theory when we think about the characteristics of stuttering, and for me, it supports many of the characteristics of stuttering. We have research, in general, "self-reports" (which is the type of evidence we have regarding the influence of emotions on stuttering), showing a correlation between the increase/decrease of stuttering and emotions. This shows that emotions at least influence stuttering, and it might not be in the way the theory postulates. We even have a few cases, though limited, of "psychogenic stuttering," which are cases of reversible stuttering that emerge after trauma. The evidence points, only points, without direct evidence, to emotions as an important factor in stuttering (just like genetic factors, which have not been found yet and remain as "hereditary" factors because we lack information about which genes are responsible). It’s not the main cause, since we already know that stuttering follows hereditary/gender patterns, etc., but it has a strong chance that it can be one of the most important factor that stuttering is related, like the seasonality of symptoms, the intensification of symptoms depending on the situation, and so on. I think this theory is really sophisticated, and in fact, it’s the best I’ve found to explain it. Other theories, like those of "the brain failing to send and receive speech signals," don’t even try to explain the variations in stuttering and just attribute its occurrence to a somewhat random factor that we dont understand. In fact, the behavior desintegration is not only presentes on sttutering, but in other behaviors too, what makes it cool to think about it (at least for me). We have a lot of information about the functioning of stuttering, and from that, we can think about the causes. But discussing the causes with clear evidence, in the case of stuttering, doesn’t really get us very, cause most evidences are partial or unconclusive. So, I tried just to look at we know about stuttering, my personal experience of stuttering, and say "oh thats make a lot of sense and would explain a lot". Maybe your personal experience wont match and that's ok. Unfortunately, I didn't address these topics in my master's thesis... but we have some theories that attempt to explain aspects of stuttering. For example, we have psychoanalytic approaches (which I personally don't like due to their lack of scientific concern), we have approaches that try to explain stuttering as a learned behavior (called 'operant behavior,' which, for me, doesn't align with the characteristics of stuttering), there are studies regarding the relationship between stuttering and dopamine (also quite theoretical), there's a lot out there, and little evidence hahaha, studies on the personality of people who stutter, on the impacts of stuttering on people's lives (those that don't imply causes, only psychological consequences of stuttering)