Phrenology was once popular and believed in typing people by the shape of their head. It is now considered a superstition, and today we measure personality with Psychometrics.
And just as phrenology was once popular, mbti today is popular, but both are superstitions based on fantasy and not on evidence and reason.
We do though cling onto our fantasies as though our life depended on it, and when our life did depend on the unconditional love of our parents, we had to repress any failure on their part, and compensate with the fantasy of their complete unconditional love.
So as babies and small children, as far as we were concerned, our life did depend on our fantasies.
Of course these are unexamined fantasies, and we take them with us unchanged into adulthood. So we cling to our fantasies just as a baby clings to their mother, just as we cling to mbti.