I feel like you are teasing me or even disbelieving... Freud and Adler did study it but it doesn't have to mean they ware right... While you completely misinterpreted how Wittgenstein who stuttered didn't write anything on it, but I used him in my example why you keep miss interpreting... I give you the "stuttering from the Anus" https://www.google.com/url?sa=t&source=web&rct=j&url=https://cjds.uwaterloo.ca/index.php/cjds/article/download/299/519/&ved=2ahUKEwiJuIqOhOLkAhXElosKHYcJClYQFjAAegQIAxAB&usg=AOvVaw0jvtPilw7Mndmn6YVXPxAX