This is a common one, although almost exclusively in one direction: Nines who mistake themselves for Fives.
This happens for two reasons: First, Nines in general are the type that have the hardest time figuring out who they are, because of all types, their sense of self is the least clear. Secondly, many Nines mistake Fives for being the „thinking“ type, and they believe that because they have quite a few profound insights and spend a lot of time thinking, they must be Fives.
A lot has been written about the difference between the two types. To keep it short, it’s enough to simplify it to one basic difference in their core motivations:
Nines strive for peace and resolution – their thinking usually tries to simplify and to arrive at a common denominator. It underscores their easygoing, patient and accommodating nature.
Contrast this with Fives, who don’t care that much about pleasant resolutions, because what they need is clarity, even if it comes at the cost of simplicity. Their thinking is complex, unresolved and relentless, and it shows in their strong-minded and argumentative nature.
Nines feel instinctively at ease in the world, and their thinking reflects their unconscious desire to merge with it. Fives fear to be overwhelmed by the world, and their thinking is an unconscious defense against it, to try to master the world with their minds.
Consequently, Nines like to think deductive: From the big and general to the small and applicable. Fives like to think inductive: From small pieces of fact to a unifying theory.