Jung states in the beginning of his PTypes, that his descriptions are of unhealthy, one-sided types, since as errbody knows we are equally E/I).
He goes on to literally state, "The attitude of the unconscious as an effective complement to the conscious extraverted attitude has a definitely introverting character. It focuses libido upon the subjective factor."
From this, we gain a spectrum of Extro-Introversion, namely:
ESFj = most extroverted, followed by ESFp
INTp = most introverted, followed by INTj
Why is it that ESFp is regarded as a heavy social, and INTj as a heavy researcher?
If S/T are External elements, shouldn't ESTj be the most extroverted?
If N/F are Internal elements, shouldn't INFp be the most introverted?