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What do J & P really mean?


What do J & P really mean?

Mark & Carol The Editors, February 1, 2012

Man Ray, Misunderstood, 1938The common modern practice of considering all ‘Js,’ including the ‘I—Js,’ to be ‘Judging types’ and ‘I—Ps’ ‘Perceiving types’ diverges from Jung’s use of the terms to refer to the dominant and may be contributing to a tendency to interpret the fourth letter of the type code in a misleading way. This oversimplification does a disservice to both Jung and Myers: It overrides Jung’s definition of these concepts, and it obscures both the underlying concept of Extraversion in Myers’ J—P dichotomy and the originality of Myers’ and Briggs’ contribution to Jung’s theory.

Jung focused on the types as defined by the dominant function. Although he noted that such types are not likely to be found “in such pure form in actual life” (1971, para. 666), observing that the other less conscious functions would modify the caricatured personalities of his examples, his section on the auxiliary function seems almost an afterthought. Myers filled that gap by designing a way to identify the auxiliary function, thus extrapolating sixteen types by adding the auxiliaries to Jung’s eight dominant-function types.

Jung considered all of the types that the MBTI® code identifies as I—J to be Perceiving types,1 and all I—Ps to be Judging types,2 because of his emphasis on the supreme importance of the dominant function. For ISTJ, for example, introverted Sensing (Si), a Perceiving function, is what is most important. For ISTP, it is introverted Thinking (Ti), a Judging function. It should be noted that Jung’s categorization also implies different cross-type compatibilities and oppositions than does the J—P classification on Myers’ type charts.

Though Isabel Myers appears to have understood, agreed with, and applied Jung’s understanding of ‘judgment’ and ‘perception,’ she also used the terms in a new way. To identify the auxiliary function, Myers needed a way to determine which function is extraverted and the J—P dichotomy was born. She was also trying to reconcile Jung’s theory with Katharine Briggs’ observations of how people use judging and perceiving. According to the MBTI® Manual, “The J—P dichotomy has two uses. First, in conjunction with the E—I dichotomy, it is used to identify which of the two preferred functions is the leading or dominant function and which is the auxiliary function. Second, it describes identifiable attitudes or orientations to the outer world.” (Myers, et al., 1998, p. 26). Myers continued to use the terms the way Jung used them in Psychological Types, as indicating the dominant function, but she also used them for the new purpose of pointing to the preferred extraverted function.

Myers’ and Briggs’ innovative application of Jung’s theory of judgment and perception made later innovations possible, such as Keirsey’s Temperament theory and Beebe’s Eight-Function Eight-Archetype model. But Myers’ J—P language has caused confusion because she used the terms both ways: in her text to indicate the dominant (1962, pp. 9-16); and in her charts to indicate the extraverted function (1962, p. 18). She could perhaps have avoided the confusion if she had called her new dimension something like the ‘JX—PX’ dichotomy, ‘JX’ for Judging extraverted and ‘PX’ for Perceiving extraverted.

It is undeniable that Briggs and Myers identified something real with their J—P characteristics, because this dichotomy has been so reliably used to identify type codes and to enhance personal and work relationships. But is it getting at who we really are? Have we lost something in forgetting Jung’s J—P categorization? If the J—P dichotomy focuses exclusively on our interface with external reality, then we may all be more than we seem, e.g., ‘P’s could be more ‘J’ than they appear and vice versa.

What is your understanding of the theory? What does the J—P score really assess? What are your observations?


1 “The two types just described [Si and Ni dominant] are almost inaccessible to judgment” (para 664).

2 “Both the foregoing types [Fi and Ti dominant] may be termed rational, since they are grounded on the functions of rational judgment” (para 644).


Jung, C. G. (1971). Psychological Types. Princeton, NJ: Princeton University Press.

Myers, Isabel Briggs. (1962, 1970, 1976). Introduction to Type®, second edition. Gainesville, FL: Center for Applications of Psychological Type, Inc.

Myers, Isabel Briggs. (1998). Introduction to Type®. Palo Alto, CA: Consulting Psychologists Press, Inc.

Myers, I. B., McCaulley, M. H., Quenk, N. L. and Hammer, A. L. (1998). MBTI® Manual. Palo Alto, CA: CPP, Inc.

Header Image

Man Ray, “Misunderstood,” 1938


Mark & Carol The Editors

Mark & Carol The Editors

Editors Carol Shumate, Ph.D., ENFP, and Mark Hunziker, INTJ, founded Personality Type in Depth as a forum to bridge psychological type and depth psychology. Both editors are themselves writers and they work together virtually, from North Carolina and Vermont respectively. Shumate's career has been in journalism, publishing, and higher education, while Hunziker's has been primarily in organization development consulting. Shumate's current project is a book on the Trickster archetype in leadership, and Hunziker's is about depth typology, a term he has coined for the interface of the two fields.

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Comments (1)

Elizabeth (Liz) Hallows

Thank you Carole and Mark, for your fantastic Journal articles and the Art you use as Header Images. Your wonderful summary of the confusion by Type teachers/ clients around Jung’s J and P meaning is my pet concern too. So many folk do not realize Jung is talking about Judging (rational Types) as E – – J and I – – P in the MBTI codes. Perceiving (irrational types) as E – – P and I – – J in the MBTI codes. You have nailed the situation and clarified it – as wonderful editors that you are.
I hope to quote you from now on in my own Research reporting of my HANDscapes results that I have found in the hands of Dominant Judging Types. Volunteers who clearly prefer E and J or I and P in their Profile are the Rational Types. Criteria preferences called Thinking or Feeling (Valuing) were not so accurate or important in my results but the directional attitude of the judging function is what I can deduce accurately 90% of the cases. How come I can deduce the preferred orientation of the judging function using one permanent hand feature is still a physical mystery. After 25 years of data collecting we keep blind testing my observations. You might remember me hand printing volunteers at many USA and UK conferences when I lived in Houston, and then Paris until 2010. I will be presenting at our AusAPT Brisbane conference 2023 this September. Are you interested and able to attend AusAPT this year? Cheers from Brisbane, Australia. Liz E N T P

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