I think typology is largely an exercise in narcissism. Everyone wants to know their type, as if that provides some motive force in self discovery, but it does not. It doesn't help you understand others either. It provides a structure of misleading generalizations that are circular and without consistancy, based in other notions which are also vague and without real meaning, and are arbitrarily chosen. Astrology is more interesting, but similarly vauge and disconnected from reality. But at least it doesn't pretend that it's conclussions are scientific or valid. ego syntonic omphaloskepsis rules the roost in typology (see any post by a self declared INTJ).