Let the record reflect that reckful waited 20 hours before posting in this thread... :tongue:
Contrary to what you sometimes hear, and notwithstanding that there are important distinctions to be made between "hard sciences" and "soft sciences," the four MBTI
dichotomies now have decades of data in support of their validity and reliability — and a combination of meta-review and large supplemental study in 2003 (
link) concluded that the MBTI was more or less in the same category (if not on a par) with the Big Five in terms of its psychometric respectability.
Anyone who's interested can read more about that — and about several other issues often raised by people claiming to "debunk" the MBTI — in
this post and
this post (also linked to in the first linked post).
Carl Jung — mystical streak notwithstanding — was a believer in the scientific approach, and Myers took
Psychological Types and devoted a substantial chunk of her life to putting its typological concepts to the test in a way that Jung never had, and in accordance with the psychometric standards applicable to the
science of personality. Myers adjusted Jung's categories and concepts so that they better fit the data she gathered from thousands of subjects, and by the start of the 1960s (as the leading Big Five psychologists have acknowledged), she had a typology that was respectably tapping into four of the Big Five personality dimensions — long before there really was a Big Five.
Buuut it's also worth noting that, contrary to what some of the function aficionados would have you believe, the scientifically respectable side of the MBTI is the dichotomy-centric side — and the dichotomies differ greatly from the so-called "cognitive functions" in that regard. The functions — which James Reynierse (in
"The Case Against Type Dynamics") rightly characterizes as a "category mistake" — have barely even been studied, and the reason they've barely been studied is that, unlike the dichotomies, they've never been taken seriously by any significant number of academic psychologists. Going all the way back to 1985, the MBTI Manual described or referred to somewhere in the neighborhood of 1,500 MBTI studies, and as I understand it,
not one of the many study-based correlations reported in the manual were framed in terms of the functions. The third edition of the MBTI Manual was published in 1998 and, as Reynierse notes in that same article, it cited a grand total of
eight studies involving "type dynamics" (i.e., the functions model) — which Reynierse summarizes as "six studies that failed, one with a questionable interpretation, and one where contradictory evidence was offered as support." He then notes: "Type theory's claim that type dynamics is superior to the static model and the straightforward contribution of the individual preferences rests on this ephemeral empirical foundation."
Although, like Myers, the official MBTI websites continue to give a certain amount of lip service to the cognitive functions, they've never endorsed the Harold Grant function stack and its associated "tandems" — where INFPs are supposedly Fi-Ne-Si-Te, and you're either an "Ni/Se type" or an "Si/Ne" type (for example). And setting aside that function stack (which has no respectable support behind it), the bigger issue is that official MBTI sources also continue to be
heavily dichotomy-centric, and to reflect the fact that virtually
all the respectable psychometric support for the MBTI is support for the dichotomies and not the functions.
The 17-page report that an ENFJ (for example) receives after taking the relatively recent MBTI
Step II test includes page after page of dichotomy-based analysis (including five separate subscales for each of the four dichotomies) and not a single mention of "extraverted feeling" or "introverted intuition" other than a diagram near the end that shows that "ENFJs like Feeling best, Intuition next, Sensing third and Thinking least," and one brief note about tending to use Feeling in the "outer world" and Intuition in the "inner world."
All the rest of the ENFJ descriptions in the report — after the brief initial profile, which isn't broken down by components — are descriptions of N (not Ni or Ne), F (not Fi or Fe) and so on, and they're the
same descriptions of N and F (and the five subscales of each) that ENFPs receive in their reports (notwithstanding the fact that ENFJs are supposedly "Fe-Ni" and ENFPs are supposedly "Ne-Fi").
Here are the two official MBTI sources backing up the validity and reliability of the MBTI typology in its Step I and Step II incarnations:
Step I:
MBTI Form M Manual Supplement
Step II:
MBTI Step II Manual Supplement
Those sources refer (directly and indirectly) to a large number of studies providing scientific support for the MBTI, and display lots of the correlations and other relevant data. And there isn't
a single mention in either of those sources of any "cognitive function."
But alas, Myers' lip service to the functions created what proved to be a significant
marketing opportunity for a handful of MBTI theorists who've made names for themselves in the last 20 years or so by peddling a more function-centric version of the MBTI. And for better or worse (and I think it's unfortunate), both the CAPT and Myers-Briggs Foundation websites have long reflected the attitude that the MBTI "community" is basically all one big happy family, and — within certain limits — dichotomy-centric theorist/practitioners are free to be dichotomy-centric and function-centric theorist/practitioners are free to be function-centric, and everybody can sell their books and hold their seminars and it's all good.
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As a final note, for any function fans in the audience who may be sitting there going, well, but how can the functions have
no validity when it's pretty freaking obvious that Si-doms (IS_Js), for example, tend to have "Si" stuff in common?
And if that's what you're wondering, it's important to keep in mind that typical modern function descriptions, rather than reflecting Jung's original concepts, are essentially jerry-rigged sets designed to match up reasonably well with the MBTI types that purportedly have them as their dominant or auxiliary functions. And as one dramatic example, and as described at length in
this post, the description of "Si" you'll find Thomson, Berens, Nardi and Quenk using bears little resemblance to Jung's "introverted sensation" and is instead a description made to match MBTI SJs.
And so yes, absolutely, if somebody's using one of those modern "Si" descriptions, and is looking for the personality characteristics in that description to show up in SJs, then that description will have "validity" to that extent. But it's just
piggybacked validity — by which I mean validity that piggybacks off the underlying validity of those two dichotomies (and the personality characteristics that tend to result from the combination of S and J preferences).
The reason Reynierse refers to the functions as a "category mistake" is (1) that 50 years of MBTI correlational data strongly indicates that it's the four dichotomies (which substantially correlate with four of the Big Five factors) that correspond to the real, substantially genetic, underlying "clusters" of personality, and (2) that in
every case where the "type dynamics" of any cognitive function model predicts correlational patterns that are in any way inconsistent with, or go beyond, the correlations you'd expect from simple, additive dichotomy effects, those function-model correlations
fail to show up.
Did you just do a study correlating some "Si" aspect of personality with the types? Good for you. Did you find that the four SJ types ended up together at one end of the correlational spectrum? That's good, too, and indicates that you were working with an "Si" description that had at least some "validity" in that respect. But now, what about the IN_Ps? They've got "tertiary Si," right? Did they show up on the same side of the spectrum as the SJ types (although maybe not so close to the far end) and on the other side of the spectrum from the "tertiary Se" types? No?? Well, don't feel bad.
That never happens. The notion that INFPs have "Si"-related aspects of personality that they share with ISTJs and that ENFJs (as "tertiary Se" types) don't share with ISTJs has just as much respectable validity as the notion that two people born on the same day have similar personalities because they're both Capricorns.
