Are you 1) the way you are because of your personality type, or are you 2) your personality type because of the way you are?
Maybe you're thinking both. But if you are, then let me ask you this: which came first, the type or the behavior? If both options are true, then you have a circle. But where did the circle begin? And if you must explain where the circle began, then that essentially forces you to choose either option 1 or option 2.