On "blocking"

Continuing a dialog with John Harrison in response that his feeling that blocking is a "strategic response"

Yes, we part company. It feels to me like a bunch of sand has been thrown,
so to speak, onto my speech apparatus. And that causes me to stumble, not
everywhere "at random" but at linguistically significant points, such as
word beginnings. I think not because these words are somehow "loaded" but
simply because they are there. It's as if speaking is like crossing a stream
by hopping on stones. If your legs get weak you end up slipping and stumbling
on some of them.

John feels that there is always an "approach avoidance" conflict present in blocks. He asks "how do I know it's not present"?

That's right, I don't know, and neither do you. I think it's great that,
having both had the dubious "advantage" of feeling stuttering from the
inside, we have concocted different "models". This should give some
reassurance to our friends SLPs who don't stutter!

We agree on so many things that I had lost sight of (or never understood) what
we did not agree on. It really would be boring and perhaps hopeless if we
all marched in lock step. The important thing is we have identified two
possible "models" (if mine can be thus dignified). You attach important
psychological udertones to blocking, I, while not denying that
these could play a role, see "generic" tension as a more direct cause.
Your mental image is "approach avoidance" conscious or unconscious, mine
is "sand in the machinery". I think these different views can have therapeutic
consequences. The next step is to see whether there is any
evidence out there to support one or the other. Do any SLPs and or researchers
on the list have an opinion and/or can cite evidence to shed some light?
(As usual... sorry if all this is old hat..)