I’m currently reading Personality by C.A. Meier. Dr. Meier was a close associate of Carl Jung’s, so I’ve been keen to read this book, because Jung published Psychological Types early in his career, so Meier has an understanding of Jung’s thoughts about type later on in his career.
Anyway, Meier talks briefly about how it is hard to type people, so I will provide a summary of that here.
First, Meier says that “in our neighbor the inferior function is more conspicuous than the superior one, because the main function operates naturally, almost automatically, and thus remains inconspicuous.” Also, “it is a common human weakness to see another’s Achilles heel sooner than his strong points.” We tend to look for the negative in others.
Second, in the real world we are dealing with people, not types. Things are always more complicated in the real world.
Third, type can change throughout life. “External influences such as upbringing, family tradition, education, career, the course of one’s life and fate can play a role.” Jung was very clear on this point but it is one that has seemed to be lost in many online discussions of type.
Overall he says that it is easier to make a type diagnosis by a process of elimination. This takes time, careful observation, and interaction with the person.