One of the most mind blowing thing I learnt recently is that there is not introvert, extrovert and these kind of traits present within a person. They are equivalent to the typing we use in Computer Science/Mathematics defined by psychologist to study behaviors. As certain objects can fall under multiple type, each individual do not have a type but exhibit certain behavior of so defined type. As a result, it allows psychologist to refine/narrow/evaluate things based on these behaviors. But as a person, we are constantly evolving. Once you dissociate the personality from behavior, it shows how colorful we as individuals are!