I think much the drive behind my 'scripting' is the fear of being seen as odd. I know a lot of insequre NT's do this too, especially those who have abandenment issues. But for me, I feel I do it so as not to look weird, anxious of affected.
I was told every day of my life as a child that i was odd, mad, crazy etc, so out of survival I learned to act normal and part of acting normal was doing all the rehersal / scripting stuff.
I think I lack confidance to me myself in the company of those who i fear might judge me.
The extent to which I was told i was wrong as a child for being my natural self, is the extend to which I have attempted to act normal as an adult. I know it is sad, but I am starting to be more myself these days.