Gil: It order to help each other it is important to be precise with our words, and meaning.
The "flinch" with (usually high recoil) handguns and rifles is a recoil avoidance response, not too different from the "duck & cover" response to an explosion. One can become habituated to the noise and recoil with the technique you describe.
The shotgunner's "flinch" is a neurologic disorder called focal dystonia. The primary action is the "trigger freeze" followed by a host of not very entertaining body reactions. It is not "fear of recoil" or "apprehension", although stress and lack of focus can certainly worsen a shotgunner's flinch - as will the anticipation of having a dud shell. There is "dartitis", golfer's swing/putting "yips", and baseball player's throwing "yips" and none of the movements are associated with recoil. I can now flinch (mostly jerk the forend down) well before pulling the trigger so it's now more than the "trigger freeze".
It's all discussed at length in the link I posted.
Although there are ways to mitigate our flinches, none of us can guarantee a cure - but release triggers are close. And as Buzz observed some continue to flinch despite release triggers, flinches which IMHO ARE mostly visual flinches. But none of know how a release trigger can resolve visual flinches either. Or why most flinchers never flinch bird hunting with pull triggers.
