Perhaps you are familiar with the emic vs. etic debate in the social sciences.
“Emic and etic, in anthropology, folkloristics, and the social and behavioral sciences, refer to two kinds of field research done and viewpoints obtained;[1]from within the social group (from the perspective of the subject) and from outside (from the perspective of the observer).”
Historically, field workers would impose their own categories and theoretical framework to understand their subjects -- the etic perspective of outsiders.
In the 1970s, the 'cultural turn' championed by the likes of the (cultural) anthropologist Clifford Geertz argued that cultures needed to be understood on their own terms. This shift toward an emic insider perspective implied that the fieldworker's primary job was to understand and interpret -- in a sense, to translate for outsiders (Westerners, e.g.) -- the self-understanding of the subjects.
This debate seems recapitulated in the MBTI vs Big Five debate.
The MBTI was based on an interpretation of Jungian ideas which Jung himself derived from studying traditional cultures -- in particular, his concept of introversion vs. extroversion (that came from things like Yin vs. Yang dualism). This is very much an etic, outsider understanding (again, it's Myers and Briggs outsider interpretation of Jung's outsider interpretation of diverse world cultures and what they have in common).
Big Five supporters argue that this is extremely arbitrary and subjective, even irrational.
The Big Five test, in contrast, derives its own five basic factors from a linguistic analysis of the English language. Using sophisticated computer analysis, it was found that definitions of personality traits in English-language dictionaries tended to cluster around five basic ideas: openness, conscientiousness, extroversion, agreeableness and neuroticism.
These factors are kind of a distilled version of the categories of thought on human personality circulating in the contemporary English-speaking world. This is cultural anthropology via supercomputers, and immensely emic (insider knowledge by the subject of themselves). Big Five supports argue that this is pure objectivity.
However, the funny thing is that the Big Five factors -- by the standard theoretical account within the social sciences of insider emic self-knowledge -- is not really any more objective than anything else.The categories simply derive from a different source -- from the subject rather than from the social scientist. That is not objective.
In fact, what if the logic of the Big Five were brought to the DSM?
Psychologists could interview and survey all the most dysfunctional mental patients in the English-speaking world to find out what they thought ailed them, then use super-computers to refine and systematize their ideas.
Supposedly “arbitrary” categories imposed by psychologists, like “paranoid schizophrenic” would disappear.
Instead, the DSM would then state that people who believed that they were Napoleon should be understood to REALLY BE Napoleon Bonaparte, after all.
