I’ve always pictured stuttering is like walking a balance beam that you’ve inherited or come by physiologically. if your stutter is mild you fall off but not that much. Add anxiety and stress and your beam narrows—you fall off and stutter more. With a. more severe stutter you start with a very narrow beam and add stress and anxiety the beam becomes a tightrope. In other words I think stuttering AND stuttering SEVERITY is to some degree neurological- inherited. That said severity is also influenced by anxiety and stress.