Fi

Introverted feeling types have a wealth of warmth and enthusiasm, but they may not show it until they know someone well. They wear their warm side inside, like a fur-lined coat. Reliance on feeling leads them to judge everything by personal values: they know what is most important to them, and they protect it at all costs.

Isabel Myers, Gifts Differing

This process helps us know when people are being fake or insincere or if they are basically good. It is like having an internal sense of the “essence” of a person or a project, and reading another person or action or project with fine distinctions among feeling-tones. When the other person’s values and beliefs are congruent with our own, we are inclined to feel kinship with them and want to connect with them.

Linda Berens, Dynamics of Personality Type