>Or is there a division in the camp of what causes stuttering? Is it rooted in the brain or is it physical (an issue with the vocal cords, larynx, etc)? Good questions. The PhD researchers Yairi and Ambrose have summarized all the biggest stutter research and made conclusions. They state that persistent developmental stutterers likely don't have physical impairments, likely it's also not an issue of muscle coordination, rather the evidence leans more towards motor planning and motor execution deficits. See [these](https://www.google.com/search?q=%22stuttering%22+%22research%22+%222022%22+%22planning%22+%22execution%22) research posts or ask chatgpt to summarize, make conclusions and generate interventions so that you understand 'speech motor planning and executions' clearer. New research (e.g., [this](https://www.frontiersin.org/articles/10.3389/fnhum.2022.894676/pdf) research from 2022) states, that when PWS **speak fluently** when alone that there are still differences in the brain between PWS and People Who do Not Stutter (PWNS). Whereas PWS who **speak fluently** during choral speech, don't have differences in the brain. This could lead to the conclusion that, when we **speak fluently** alone, that we are still excessively monitoring, paying attention to stuttering and doing interventions to maintain fluency, which causes the right-hemisphere to be hyperactive. Choral or synchronical speech (where we speak in unison with classmates for example) includes an element of 'distraction' where we move our attention away from stuttering and instead, we focus on keeping up with the forward flow of speech. In [this](https://www.reddit.com/r/Stutter/comments/11p1vnu/comment/jbvqkq4/?utm_source=share&utm_medium=web2x&context=3) post I made a conclusion about the stutter cycle that causes speech blocks.