I'm with you, unlike the others. Stuttering is an unconsciously gained anxiety mechanism, deeply built into preverbal mechanisms. It's way more likely the brain changes itself after someone's personality than the other way around in young people, if you don't have any metabolic or cerebral disease. The genetic part is all about PREDISPOSING you to stuttering, not causing it, which means psychological and externalfactors are essential in triggering it. It's the same with addiction, soms are easily addicted, others can take heroine without problems. This is why people can talk smoothly to themselves or sing; the expectation of having no external critic and thus making no mistake (because with singing you know exactly what to say) resolves the problem completely. Stuttering runs in families due to the genetic part but also the unconscious mimicking part. I've had a big stutter myself and used all the excuses available. I am more sensitive to stuttering genetically (it runs in my family), but acknowledging there actually is anxiety and learning to accept that is what resolved it fully. You cannot change your genetics, but you can place your locus of control with stuttering within yourself by focusing on the factors you can control, and you are all lying to yourself by saying you don't have anxiety, because we do, and that's okay. ​​