Plywood wrote:
Introversion and Extraversion isn't proven.
As something can be proven in psychology, I think the introversion/extraversion axis is "proven"; at least, in almost all factor analysis of psychological traits had emerged a dimension more or less equivalent of "introversion/extraversion" (the only exception that I remember is the Heymann-La Senne study[
link], who identified the dimensions "emotivity", "activity" and "ressonance", but not "introversion" or "extraversion")