I have a nerdy ISTP friend who mistyped as INTJ for several years, because she has so many theoretical/cerebral interests. e.g. She spent all summer working on a sci-fi novel -- or at least, trying to make a coherent world, based on existing physics theories.
She does come across as much more earthy and practical, than the INTJs in my life. Very direct and no-frills in conversation, very chill. Example: Saw her after three months, and she'd lost about fifteen pounds.
Me: Oh my god, ISTP, look at YOU! You look great!
INFJ friend: How did you do it?!?
ISTP friend: *shrugs* Ran more. Ate better.
The INFJ and I both tend to be pretty wordy about those sorts of things, and the INTJs I know would probably have turned it into a little story, too. But for my ISTP friend, it's that simple. Very refreshing!
