What are some of the biggest differences between high Fi and low Fi?
I think the biggest difference for any “high vs. low” version of a function would be that the low version is going to necessarily be secondary to the flip side of the function. So, TJs are going to have Fi but it’s always going to be less natural to them than Te, and using Fi without that Te lens will be difficult. Also, high Fi is going to be paired with Ne or Se, and low Fi will be in a person with high Ni or Si, so the whole motivation changes. The point of this rambling is that I’m going to try and talk about Fi on its own but really, context is always key.
The biggest difference I’ve seen is that healthy high Fi is very confident in its likes and dislikes and values, whereas lower Fi isn’t. For this exercise I’m going to compare myself to ISFP sister, since we had a pretty similar upbringing and are close in age, but she’s an Fi dom and I’m Fi-tert.
ISFP sister never really went through a hipster/snob/”I’m not like other girls” phase, which I definitely did. There’s this perception that Fi doms are the hipsters of MBTI but actually they are the people who like what they like, regardless of whether it’s popular or not. So they can indeed be into the very obscure, but they can also be huge fans of blockbuster movies and top 40 mainstream music, and they don’t really see a difference - it’s just what they enjoy. I on the other hand, if I may seriously date myself, was obnoxious towards people in college who only had the Shins songs off the Garden State album because I loved the Shins before that movie and had several albums. Lower Fi seeks to prove its individuality and different-ness. High Fi is secure in it.
High Fi is also I think more consistent in morality but less rigid, if that makes sense. My sister has had pretty consistent political views from her late teens on, but is also more willing to listen to and understand other viewpoints. I’ve shifted my views over time pretty considerably but I’ve also always been a bit guilty of thinking whatever I believe at the time is right and somewhat dismissive of other views (and then when I change my view feel like an asshole). I feel like I’m only now able to approach opposing views with more empathy, and I say this as someone who was in college at a time when Garden State was still considered semi-relevant. On the other hand, in our teens, ISFP sister was way more likely to speak up (respectfully) if someone said something she disagreed with on a moral stance, whereas I was more likely to just write that person off as just never understanding.
I think those are the biggest differences. She is definitely more emotional than I am, but I think there’s a lot of factors that go into that beyond Fi. Overall, a high Fi user is probably going to act more like the stereotypes of an Fi aux (fun, morally guided but not sanctimonious about it, interested in all kinds of things from a wide variety of sources) and a low Fi user, somewhat ironically, will act more like the stereotype of an Fi dom (more in need of validation, can be self-righteous, can be pretentious).