**->** All recent research (within the last 15-20 years) points in the opposite direction from your proposed theory and states that it is a mix of genetics and neurobiology and can be influenced by outside factors (not caused by it). Everything you said in this paragraph follows the Brutten and Shoemaker theory: "mix of genetics" = Genetic predisposition as the theory states. "neurobiology": The effect of disintegration is a biological effect. The authors simply say that the availability of the effect is genetic, but they do not explain the physiological mechanisms behind the effect, which may very well be related to neurotransmitters, dysfunctional brain activation, synaptic errors, or something neurobiological. "outside factors" = Classical conditioning. Stuttering is not a learned behavior from emotional learning or classical conditioning. Again, that’s not what the theory says. If you want to share the data you mentioned, that would be cool too! A search for absolute truth here doesn’t make sense. What is interesting to me is discussing the evidence in light of the characteristics of stuttering and thinking about theoretical models. We will have only theoretical models to explain stuttering for a long time still. Just out of curiosity, although this is a theory from the 60s, Gene Brutten and Shoemaker were not fools. They were two people who stuttered and were students of Charles Van Riper and Oliver Bloodstein, two of the greatest stuttering researchers in history (and people who stuttered too). They produced a lot on stuttering, formulated this theory, and positioned themselves well with the evidence of their time.