Jungian personality types and astrology are two completely different entities and do not have any sort of connection with one another. MEANING: You should not use your star sign to figure out your personality type. Connections and similarities ARE evident between both practices, which I will explain in further detail, however these are merely coincidental. Astrology was not a source of inspiration behind the development of personality theory.
Though both are regarded as "pseudoscience", I believe there is more scientific evidence and research done behind personality theory. ISTJ type is derived from four cognitive, or mental functions: introverted sensing, extraverted thinking, introverted feeling, and extraverted intuition, respectively. To be an ISTJ, it is implied you use this functional stack.
There are eight cognitive functions involved in Jungian personality theory:
FOUR judging functions.
Introverted Feeling (Fi)
Extraverted Feeling (Fe)
Introverted Thinking (Ti)
Extraverted Thinking (Te)
and FOUR perceiving functions:
Introverted iNtuition (Ni)
Extraverted iNtuition (Ne)
Introverted Sensing (Si)
Extraverted Sensing (Se)
ISTJ leads with dominant introverted sensing, which means they prefer to preserve routines, traditions, and past ways of doing things. They trust the "tried and true" and, by utilizing their auxiliary extraverted thinking, they strive for efficiency in their work, often referring to objective facts rather than feelings which are subject to change.
There ARE similarities between general descriptions of ISTJ and the Capricorn star sign, as stereotypically, both are described as hard workers, intelligent, rule followers, serious, perfectionistic, etc. They also both get a bad rap of being "boring" and "lacking creativity." However, this is not the case. The MBTI system seems to have a strong bias for iNtuition, often claiming sensors do not possess creativity. In astrology, enthusiasts often claim that earth signs (Taurus, Virgo, Capricorn) also lack creativity and are rather bland. So you can equate the stereotypes of earth signs in astrology, and sensors in personality theory.
SINCE introverted sensing (Si) is so concerned with maintaining the tried and true, it's not too rare for them to get a "stickler for the rules" or "schedule making" reputation. Stereotypical Capricorn posts thrive off of such observations. Auxiliary extraverted thinking (Te) is all about organization, following through with plans, and checking off the items on Si's to-do list. Te refers to logic and facts rather than personal feelings and opinions as introverted feeling (Fi) would. Already, you can see the associations between Capricorn and these two functions.
ISTJ's lower two functions, introverted feeling (Fi) and extraverted intuition (Ne) may, at a closer glance, look like Aquarius or Gemini. Introverted feeling is all about authenticity and doing what "feels right" TO the person engaging in the action. Fi is a decision making function, just like extraverted thinking (Te). A notable difference between the two is that they're on opposite ends of the spectrum. Fi refers to VALUES, MORALS, and WHAT FEELS RIGHT while Te wants to know what will GET THE JOB DONE most EFFECTIVELY. They don't care about feelings.
Since Fi is concerned with authenticity and remaining true to oneself, it can be closely related to Aquarius. People under this sign are also described as individualistic, quirky, and in touch with their values. Extraverted intuition (Ne) may play a role here too, since Ne is associated with creativity, ideas, and originality. Extraverted intuition can also look like Gemini if we're looking at its inconsistent, indecisive, random nature. Just like Geminis are always changing their minds, according to astrological assumptions, extraverted intuition naturally considers all possibilities and angles of a situation, so it may be very jumpy and scattered.
ISTJs, unless over 50, do not have fully developed introverted feeling and extraverted intuition, so such characteristics will not be strong in their personalities. Even then, these will ALWAYS be their inferior functions, so they won't be able to utilize them in their full potential as somebody with dominant Fi or Ne would.
I don't believe one is based on the other, as I said before, they're separate areas of study.
· 1 month ago