Psychogenic stuttering is believed to be extremely rare, as it is caused solely by psychological trauma or something similar. Developmental stuttering (likely what nearly all of us on this sub experience) may be influenced by difficult mental/emotional experiences, including trauma, but is not initially caused by the trauma. Every individual with developmental stuttering begins to experience it in childhood has a genetic component to their stuttering, but psychogenic stuttering can begin at any time and is not caused by genetics.