Yeah, introverts have to train themselves to get that internal monolog and move it outside to where others can hear it too. I did it as an INFP when I decided that I wanted to learn how to socialize better, and it was a very conscious process for me.
ISTPs have Ti as their Dominant like INTPs, so they probably have a pretty good internal monologue. Their Se orientation makes it pretty earthy. I think maybe their biggest issue is that ISTPs don't want to have to go through the step of self-censoring as part the process of extraverting their internal voice. I had a couple ISTP buddies in the service, and they had plenty to say once they trusted me. But they didn't trust themselves to talk freely in social settings. I suspect they didn't want to have to monitor their speech and self-censor even when the conversation would have interested them.
I remember struggling with self-censoring issues when I started socializing--making sure I didn't say something wildly stupid or unPC--but with practice that got automatic.
Good point, Fine Line.
This reminds me of a line from Uncommon Women and Others, a fantastic play. The shyest roommate meets the man she knows she's going to marry and soon after comes out with a great line. The other women look at her because she's never been very funny around them. She responds "Yeah, Robert says I'm a closet wit." I've always been very taken with that line.
I just fixated on the one line, which tickled my fancy. But you raise a good point. Artists have struggled with these things in their own lives and then illustrated them in their art. It's a good find.
Why would you want it? It mostly only makes you spend half the time you interact with people either biting your tongue or getting yourself into trouble.
“There are two novels that can change a bookish fourteen-year old’s life: The Lord of the Rings and Atlas Shrugged. One is a childish fantasy that often engenders a lifelong obsession with its unbelievable heroes, leading to an emotionally stunted, socially crippled adulthood, unable to deal with the real world. The other, of course, involves orcs.” ~ John Rogers
More than that. . . I use it for controlling conversations, manipulating co-workers, and making people think I'm funny, which in turn makes me likable (even though, nine times out of ten, I don't like them).
Plus, you say "biting your tongue or getting yourself into trouble." To me, "biting your tongue" is just another way of saying that the quick witted individual has a lot of choices at any given moment. I can't imagine preferring that scenario over that of having a limited amount of choices.
And the "getting yourself into trouble" part is more for Extroverts, I would imagine.
"The only time I'm wrong is when I'm questioning myself."
I have a very quick wit, I tend to save it for people I'm comfortable with, because too many of my thoughts (while quite funny), are unPC, and people get annoyed with it. (I'm not a good judge of if someone would get offended or not). I can't generally figure out if it's appropriate or not before it would no longer be funny, so in most settings I avoid using it (besides to amuse myself).