This excerpt from an earlier post gets it pretty close, too:
A major concern for INTPs is the haunting sense of impending failure. They spend considerable time second-guessing themselves. The open-endedness (from Perceiving) conjoined with the need for competence (NT) is expressed in a sense that one's conclusion may well be met by an equally plausible alternative solution, and that, after all, one may very well have overlooked some critical bit of data. An INTP arguing a point may very well be trying to convince himself as much as his opposition. In this way INTPs are markedly different from INTJs, who are much more confident in their competence and willing to act on their convictions.
Despite having got ENFP, a lot of that feels... very familiar. Probably the N and the P.
I do wonder whether there's just a dash of Barnum going on, here. I've sat and nodded along with ENFP, but now I've been shown someone else's results and I'm nodding along with that, as well. Could equally just be a flaw within the sixteen-result system, though. You can't sort people into that few distinct groups. It's not just "A little from column A, a little from column B." I think we'll all have tendencies from every column between A and P. I imagine very few people score 100% for any given letter.
Still an interesting test, particularly because it probably reveals how people like to see themselves as much as about how they actually do see themselves, but I think it's a pinch of salt thing. It's guidelines, more than rules. We
tend towards these categories, we aren't defined by them, and we're very rarely going to be perfect examples of them.