INTJs are more abstract, imaginative, and head-in-the-clouds. They are more ingenious. In general, they have better leadership ability. They also seem more random (because of the leading Ni).
ISTJs are simpler, more concrete, and formal. In general, they are harder workers. More common sense, more detail-oriented.
IN regards to leadership ability, leaders a grown more so than natural. INTJs might better leaders, but to be a good leader you have to be a good follower. Maybe they are seen as better leaders or more natural leaders in general because they refuse to follow, or have more trouble doing so seeing as ISTJs generally don't have trouble submitting to authority. I say generally because I have authority issues.. I want to be incharge.
Originally Posted by JivinJeffJones
That's the one I'd pick. INTJs are also among the worst followers as a type, I think.
Edit: I also suspect ISTJs are tidier than INTJs.
Hahah, you should see my room.
"I am what I need to be..."
"Nemo me impune lacessit - No one provokes me with impunity."
It's infinitely debatable. However, there was a study some time ago that showed that the average INTJ IQ is higher than the average ISTJ IQ. Is this to say they're smarter? Is this to say that any given INTJ is going to be "smarter" than any given ISTJ? On both counts, the answer is no. But, instead of going into a long-winded post, I put the idea in politically incorrect layman's terms.
If a deaf INFP falls in the forest and no one is around to hear it, does it make a sound?