The last bit is pretty fascinating seeing it in such a perspective. And to add to the psychological discussion, even if the manifestation is more than just how we feel, the severity of it and lasting potency still seems highly impacted on, as you say, what we know to be the case around us, whether someone will be listening, etc. I remember trying to read out loud as a practice assignment at home but thought that if I was alone I'd likely be fine and it was more meant to get my vocals going and confidence up. Hitting a mild stoppage somewhere along the way, I remember being really surprised by it because I was all alone but I easily got past it. It was so minor I could easily carry on at will. And I remember from that day on I thought if I could feel outside the way I did at that time at home, I'd be fine. Having a go-to when I stuttered definitely took the confusion away and as a few other techniques here and there got worked into it, I experimented but the ultimate goal was always to use a go-to and not worry about it going back to how I felt at home. The sooner the better, I never forgot that experience.