I'm probably not using the right word, or at least, there's a better word for it. When I say "ego" I mean the psyche, so if it is "egotistical", its origins are from within - directly contrasted against origins supported by an environment. A priori reasoning has evidence withdrawn from the equation, therefore, introverted intuition is the purest theoretical form of ego regarding personality.
The thing about this is that if you use your reasoning, almost every type will be at the very least equally capable in this regard, giving INTJ's no real advantage in terms of reconciling beliefs to existence. Even ISFP's would be better learners, with auxiliary Se (Se is better than Te, 'tis true, though they are notably similar in scope). Two exclusions might be xNxP's, with subjectively-oriented functions in both dom and aux slots, but I've only thought about that lightly.