Because of their Introverted Intuition (Ni) as the dominant function and the unusual order of their functions, they’re the only personality type that has an active access to their subconscious mind.
That’s why they have a natural ability to read others so accurate. They tend to see subconscious patterns within themselves and also in others.
In my experience, people do not see these subconscious behavior patterns or have the ability to consciously access the subconscious.
I realized just at this point in my adulthood (also since I know the MBTI test and the cognitive functions) that not everyone does this automatically.
I have talked to a few people about it, asked for feedback and tried to verbalize the process. Over time, I noticed that this process of information gathering seems completely absent in others (at least they are not aware of it or have an active access) and that no one in my environment recognizes these patterns.
In my opinion, that is why they have a natural gift in the field of psychoanalysis.