Jung’s Typology vs. Myers-Briggs Type Indicator

Yesterday’s Singer quote on intuition and feeling generated some confusion because she (interpreting Jung) says feeling is a judging process. But, but – but, if the MBTI is based on Jung’s typology, why does it consider feelings as a separate function from judging? Wha’sup wit dat? Here are the differences between Jung’s types and the MBTI:
In Jung’s types, intuition and sensation are considered perceiving functions. Thinking and feeling are are functions that process information, and to do so certain judgments must be made. So Jung has the two attitudes – introversion and extroversion (which are also commonly misunderstood), and the four functions – intuition, sensation, thinking, and feeling. This gives eight cognitive modes: IT, ET, IF, EF, II, EI, IS, and ES. No one abbreviates them in Jung’s world, I do so for brevity.
In the MBTI, they attempt to identify the dominant function and a secondary function by adding the dimension of perception vs. judging. So the MBTI has four polar dimensions – introversion vs. extroversion, intuitive vs. sensing, feeling vs. thinking, and perception vs. judging. This gives 16 modes: ISTJ, ISTP, ISFP, ISFJ, INTJ, INTP, INFP, INFJ, ESTJ, ESTP, ESFP, ESFJ, ENTJ, ENTP, ENFP, ENFJ. Everyone abbreviates these in the MBTI world, I do so for consistency.
Note that the Keirsey Temperament Sorter uses the same terminology as MBTI, but is based on different conclusions as to what factors go towards what outcomes. I don’t know what to say about that, except consultants typically need unique selling propositions.
Jung is the primary source material here. It’s not clear to me what benefit is derived from breaking out another dimension in the MBTI, especially when experience demonstrates that people who are grounded (or drowning, as the case may be) in their feelings do have the judgmental characteristics that Singer relates. [Did you know INFP’s could make such judgmental statements?] I find it more useful to study Jung, which has the depth, if not the concision. Many people are critical of the MBTI because it is not a highly repeatable test – people can change results just by taking the test again. In fact, I typically test as an INTJ, but today I tested as an INFP. Is this a situational change, a long-term change, or a fluke? Hard to tell.
There is another take on personality types in the workplace which I have sometimes found useful: Social Style/Management Style – Developing Productive Work Relationships, by Robert Bolton and Dorothy Grover Bolton. Their book outlines four styles which they call Amiables, Analyticals, Expressives, and Drivers. The helpful teaching here is learning how to “flex” your own style to adapt to the other person. The advantage of this model is that with only four types you can build a 2×2 matrix, a favorite of consultants the world over. This means it’s a bit simpler, and you can quickly explain it to someone unfamiliar with the material in a coaching situation. It doesn’t have the depth of Jung or the breadth of the MBTI, but it’s a reasonable if simplistic model.