I'll add my two cents as well. from what i understand, disfluencies are possibly connected to the basal ganglia, which has to do with timing (among other things). there have been cases of people with parkingson's developing a stutter (or at least something that looks very much like a stutter), so that's why they think the basal ganglia may be involved. they have also noted that people with parkingson's who have trouble walking will walk much better if there are cues on the floor to aid them. this is similar to pws being fluent when speaking as part of a group. just like the cues give the person help with walking, the other voices help the pws. I think it comes down to a big case of we don't really know yet. the brain is a super complicated thing that we don't understand very well. to complicate matters, i have heard that the studies that they do are sometimes just not getting consistent results when replicated, possibly because the brain is just super complicated. so, what is a pws to do? well, as rupaul said: you better work. [https://www.stutteringhelp.org/stuttering-and-basal-ganglia](https://www.stutteringhelp.org/stuttering-and-basal-ganglia)