I tend to choose for a mix of empirical/a priori science first and following the findings with a priori science to think things out.. but ok.. What I mean is.. those empiricists didn't thought of the fact that if extroverts start with meditation and introspection they start to get NOT-Extroverted and get more brain activity! You can start life on the extroverted or introverted side but you can condition yourself into something more refined. I for example are just in the middle, tests show 70% or higher introverted, perhaps because I've learned from internet texts about introvertedness and introspection..