"Significant in Jung's theory is that "type preferences" are inborn and not socially constructed through interaction with the parents, family, culture and other external influences. Even so, the individual is impacted in the quality and strength of the development in his or her preferences. Nature and nurture are both at play. A supportive environment will facilitate inborn preference development; a contrary environment will impede or retard their natural development."
there you go. the creator of type theory stated that type is innate, and it is merely the development of different functions and engagement with one's shadow that is the main difference in driving differences in function usage between members of the same type.
YOU CANNOT CHANGE TYPE. i've met ENFPs with narcissistic tendencies and a self image of being critical of others, does that make them INTJs?? ah-NOOO! so people who take the surface level of mbti research and assume it is like the "big 5" or something, please research further into the theory because the material in this is vast and every type has all their little intricacies.