Introversion/extroversion in both the Jungian and socionics sense refer to a mental orientation. These cognitive dispositions are often colloquially confused or conflated with the behavioral traits of being socially reserved or outgoing, but they are actually distinct and separate personal qualities.
Vertedness, as it's sometimes unofficially called, describes the prevailing direction of libido-
1 or information-flow
2 between objects and a subject's primary information-processing function, so it is mostly a mental phenomenon. On the other hand, the degree to which one is socially engaged or averse is a behavioral matter.
Behavior is usually epiphenomenal to cognition — action follows reflex, instinct, and thought, not the other way around. And moment-to-moment changes in situationally adaptive action have much less effect on the nature of one's essential psychical makeup than does the converse. In other words, while lifelong type-change remains up for debate, it is true that mentality is altered less readily than behavior. This fact goes far to explain the confusion we often see among self-typists who focus overmuch on correlating outward behaviors with sociotype profiles and who give insufficient attention to their habits of mentation. As a result they frequently wind up with incorrect or unstable typings.
Though it's true that we can make broad generalizations about extroverts being more socially confident and engaged, and introverts being more socially doubting and avoidant, we can also find many exceptions to this rule of thumb. Individuals of either psychical attitude can be found who exhibit the opposite postulated behavioral tendency, i.e. socially outgoing cognitive introverts and socially withdrawn cognitive extroverts. And so the aforementioned generalization is a faulty one and cannot be utilized reliably, and we must examine each person's characteristic mentality to determine their introvert or extrovert orientation.
So then, with regard to vertedness of subtypes, are you asking about a general inclination of thought or of action?
- Jung
- Kępiński, Augustinavičiūtė