Debunking the MBTI Debunkers

(Content from two posts by reckful.)

It seems like the MBTI "debunkings" have been coming thicker and faster lately, but their quality certainly isn't improving — which is hardly surprising, given the extent to which each one seems to be based largely on a quick review of previous "debunkings," rather than on the authors actually doing much serious homework.

I'm going to take more time than the latest debunker really deserves to address some of the points in the article by Joseph Stromberg (a dude who "writes about science" at the Vox website) mentioned in the OP, partly because they're mostly points commonly found in these kinds of articles, so addressing this one also addresses several previous articles, as well as (I assume, alas) several more that are still to come.

The Big Five is science and the MBTI is astrology

I have more to say about the scientific status of the MBTI below, but wanted to begin by noting that, like most MBTI debunkings, this one points approvingly at the Big Five and characterizes it as a very different kind of animal. But McCrae and Costa — the leading Big Five psychologists (and creators of the NEO-PI-R test) — long ago acknowledged (1) that the MBTI (and this was an older version than the current one) basically passed muster in the validity and reliability departments, (2) that the MBTI was effectively tapping into four of the Big Five dimensions, and (3) that the Big Five and the MBTI might each have things to learn from the other.

Discrete, bimodal types

Originally Posted by Stromberg
The test claims that, based on 93 questions, it can group all the people of the world into 16 different discrete "types." ...
With most traits, humans fall on different points along a spectrum. If you ask people whether they prefer to think or feel, or whether they prefer to judge or perceive, the majority will tell you a little of both. ...
But the test is built entirely around the basis that people are all one or the other. ...
Actual data tells psychologists that these traits do not have a bimodal distribution. Tracking a group of people's interactions with others, for instance, shows that as Jung noted, there aren't really pure extroverts and introverts, but mostly people who fall somewhere in between.

Pew! Pew! Pew! And another straw man crumples to the ground...

The notion that the MBTI claims to assign people to "pure" all-or-nothing categories is probably the silliest of the memes that regularly recur in MBTI debunkings, and it has the dual charm of being both an inaccurate characterization of the MBTI and — in its misplaced emphasis on the shape of the distribution curve — a red herring.

Nobody knows for sure at this point but, as I understand it, the existing studies suggest that it's likely that most or all of the MBTI dimensions — like the four Big Five dimensions they basically correspond with — exhibit something like a normal distribution, with substantially more people near (or in) the middle than near the extremes. For what it's worth, Jung thought more people were essentially in the middle on E/I than were significantly extraverted or introverted, and Myers allowed for the possibility of middleness on all four dimensions — so the in-the-middle possibility really goes all the way back to the MBTI's roots.

Myers believed that it might turn out that one or more of the dichotomies was truly bimodal to one degree or another — with, in effect, a more or less empty (if narrow) zone in the exact middle of the spectrum. But she never asserted that that theoretical possibility had been factually established by any respectable body of evidence, and the 1985 MBTI Manual (which she co-authored) stressed that the evidence for bimodality was sketchy at best. And since then, as I've said, quite a lot of evidence has accumulated that seems to suggest that most or all of the MBTI dimensions exhibit something more like a normal distribution.

In at least one of the early versions of the MBTI, it was possible to get an "x" on any dimension. The current version assigns people a (tentative) type on each dimension, but that's a very different thing from saying that it isn't possible for someone not to have a preference — and the MBTI Manual specifically notes that someone with a score near the middle is someone who has essentially "split the vote" rather than offered much evidence of a preference.

The "Step II" version of the MBTI includes five "facets" for each dimension — just as the NEO-PI-R has six facets for each Big Five dimension — and allows for the possibility of being, for example, on the T side of three of the facets and the F side of the other two.

More importantly, I'd say, there was really no doubt in either Jung's or Myers' minds that people on either side of the dimensions fell along a notably wide spectrum from mild to strong preferences. So, regardless of where anybody wants to come down on the "exact middle" possibility, if they take the position that, e.g., all introverts are equally introverted, their perspective is way out of line with Jung, Myers and every respectable MBTI source I've ever encountered.

As a final note: At this point nobody really knows how close to the middle how many people are on the MBTI (and Big Five) dimensions, because the current state of both the MBTI and Big Five is such that it really isn't possible to determine exactly where anybody falls along whatever the real, underlying (and substantially genetic) spectrums may be. So it seems to me that anybody who thinks that the existing data on either the Big Five or MBTI has clearly established the shape of the distribution curves is very much overestimating the ability of the existing tests to accurately quantify strengths of preferences.

But the main point to keep in mind is that, at the end of the day, the worth of the MBTI and Big Five is mostly going to hinge on how good a job those typologies do in nailing down what personality-related characteristics tend to be associated with the corresponding preferences, and not on how many people turn out to be at any particular point on any of the relevant spectrums. And in any case, the MBTI certainly doesn't stand or fall depending on whether any of its dimensions exhibit a "bimodal" distribution.

The MBTI simply implements Jung's types

Originally Posted by Stromberg
The test was developed in the 1940s based off the untested theories of an outdated analytical psychologist named Carl Jung, and is now thoroughly disregarded by the psychology community. ...
It copied Jung's types, but slightly altered the terminology, and modified it so that a person was assigned one possibility or the other in all four categories, based on their answers to a series of two-choice questions. ...
If there were good empirical reasons for these strange binary choices that don't seem to describe the reality we know, we might have reason to seriously consider them. But the fact is that they come from the now-disregarded theories of a early 20th century thinker who believed in things like ESP and the collective unconscious.

Jung was a believer in the scientific approach, and Isabel Myers took Psychological Types and devoted a substantial chunk of her life to putting its typological concepts to the test 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'd gathered from thousands of subjects, and by the end of the 1950s (as McCrae and Costa have acknowledged), she had a typology (and an instrument) that was respectably tapping into four of the Big Five personality dimensions — long before there really was a Big Five. And twin studies have since shown that identical twins raised in separate households are substantially more likely to match on those dimensions than genetically unrelated pairs, which is further (strong) confirmation that the MBTI dichotomies correspond to real, relatively hard-wired underlying dimensions of personality. They're a long way from being simply theoretical — or pseudoscientific — categories with no respectable evidence behind them.

Again, McCrae and Costa are the leading Big Five psychologists, and they've studied both Jung and the MBTI. In the same article I linked to at the top of this post, they noted — correctly — that Jung's typology erred in lumping various psychological characteristics together that decades of studies have shown are not significantly correlated. By contrast, after Myers was finished adjusting Jung's system to fit the data, she had a modified version whose dichotomies passed muster by the relevant scientific standards. As McCrae and Costa explain:

Originally Posted by McCrae & Costa
Jung's descriptions of what might be considered superficial but objectively observable characteristics often include traits that do not empirically covary. Jung described extraverts as "open, sociable, jovial, or at least friendly and approachable characters," but also as morally conventional and tough-minded in James's sense. Decades of research on the dimension of extraversion show that these attributes simply do not cohere in a single factor. ...
Faced with these difficulties, Myers and Briggs created an instrument by elaborating on the most easily assessed and distinctive traits suggested by Jung's writings and their own observations of individuals they considered exemplars of different types and by relying heavily on traditional psychometric procedures (principally item-scale correlations). Their work produced a set of internally consistent and relatively uncorrelated indices.

Jung included what's arguably the lion's share of the modern conception of S/N (the concrete/abstract duality) in his very broad notion of what E/I involved. But Myers discovered that there are abstract extraverts (ENs) and concrete introverts (ISs), and that there's no significant correlation between Myers' (statistically supportable) versions of E/I and S/N. Jung said extraverts tend to subscribe to the mainstream cultural views of their time, while introverts tend to reject mainstream values in favor of their own individualistic choices. But Myers discovered that a typical ISTJ is significantly more likely to be a traditionalist than a typical (more independent-minded) ENTP. Jung said an extravert likes change and "discovers himself in the fluctuating and changeable," while an introvert resists change and identifies with the "changeless and eternal." But Myers discovered that it was the S/N and J/P dimensions that primarily influenced someone's attitude toward change, rather than whether they were introverted or extraverted.

And so on. The appropriate way to view the Myers-Briggs typology is not as some kind of simplified (and more "testable") implementation of Jung's original typology. Instead, it's fairer to say that the Myers-Briggs typology is basically where Jung's typology ended up after it was very substantially modified — not to mention expanded — to fit the evidence.

Reliability

Originally Posted by Stromberg
We could accept the fact that the Myers-Briggs is limited in defining people in binary categories, but still theoretically get some value out of it because it accurately indicates which pole of any category we're closest to.
But that idea is tough to swallow given the fact that the test is notoriously inconsistent. Research has found that as much as 50 percent of people arrive at a different result the second time they take a test, even if it's just five weeks later.
That's because these traits aren't the ones that are consistently different among people. Most of us vary in these traits over time — depending on our mood when we take the test, for instance, we may or may not think that we sympathize with people.

The idea that the Big Five is substantially superior to the MBTI in the test/retest reliability department is another canard that periodically pops up in these kinds of articles. And claims to that effect are often accompanied by statistics that confuse retest rates on single dimensions with retest rates for a complete four-letter type.

I once corrected a forum poster who'd noted that the MBTI "has a test-retest rate of some 60%, meaning two out of every five people get different results when retaking the test," while the NEO-PI-R's "levels of consistency are incredibly high (N= .92, E= .89, O= .87, A= .86, C= .90)." In my reply, I explained:

Originally Posted by reckful
That 60% MBTI statistic relates to a retest standard that says you got a different result if any one of the four dimensions is different. That corresponds to an average test-retest rate of 88% for the individual dimensions.
If you apply the same test-retest standard to those Big Five statistics you gave us, you get .92 * .89 * .87 * .86 * .90 = a 55% test-retest rate (or 60% if you leave out Neuroticism).

It's probably also worth noting that if you assume (as previously discussed) that most or all of the MBTI and Big Five dimensions exhibit something like a normal distribution, and if you assume (accordingly) that a large portion of the population is in or near the middle on at least one dimension, and if you add to that the many potential sources of error in self-assessment personality tests — from the fact that personality type is a relatively young science and psychologists are quite a long ways from nailing down exactly what the temperament dimensions consist of, to flaws in particular tests (including items that tap into more than one dimension), to multiple kinds of misunderstanding and other human error on the part of the individuals taking the test — it would strain credibility if the test-retest statistics for any personality typology didn't indicate a significant percentage of cases where at least one of the dimensions came out with a different preference on retesting, and one letter change is all it takes to constitute an MBTI retest "failure."

As a final note, it should also be kept in mind that a typical MBTI test-taker is someone with little or no familiarity with the typology who simply takes the MBTI test along with a group of fellow employees or students. It's reasonable to assume that, to the extent that a person actually has four reasonably-well-defined preferences, they're likely to come up with a result that's considerably more accurate if, rather than just accepting the test result, they spend some time reading about the preferences and the types — which is something the MBTI Manual (among other sources) has always encouraged people to do.

Myers didn't have a psychology degree!

Originally Posted by Stromberg Jung's principles were later adapted into a test by Katherine Briggs and her daughter Isabel Briggs Myers, a pair of Americans who had no formal training in psychology. To learn the techniques of test-making and statistical analysis, Briggs worked with Edward Hay, an HR manager for a Philadelphia bank.

No "formal training" in psychology! Oh noes!

Isabel Myers may not have been as smart as Jung, but she was a very intelligent woman — she graduated first in her class at Swarthmore — who understood that, in order to create a personality assessment instrument that passed muster by the relevant scientific standards, she needed to educate herself on statistics and psychometrics. And she did. And if Mr. Stromberg thinks that the fact that Myers' education in that area happened outside of a "formal" university program means she didn't really know what she was doing, I'd suggest that Mr. Stromberg should think again.

I'd certainly expect that, all other things being equal, a smart person with a degree in psychology would have been in a better position to turn Psychological Types into a scientifically-respectable typology than a smart person with "no formal training in psychology." But, as it turns out, Briggs and Myers were the smart people who did it, and the Myers-Briggs typology deserves — needless to say, I would hope — to be judged on its merits, rather than on the basis of how much of its creators' education happened within the hallowed halls of academia.

Real psychologists reject the MBTI

Originally Posted by Stromberg
Search for any prominent psychology journal for analysis of personality tests, and you'll find mentions of several different systems that have been developed in the decades since the test was introduced, but not the Myers-Briggs itself. Apart from a few analyses finding it to be flawed, virtually no major psychology journals have published research on the test — almost all of it comes in dubious outlets like The Journal of Psychological Type, which were specifically created for this type of research. ...
Apart from the introversion/extroversion aspect of the Myers-Briggs, the newer, empirically driven tests focus on entirely different categories. The Five Factor model measures people's openness, conscientiousness, extraversion, agreeableness, and neuroticism — factors that do differ widely among people, data has told us. And there's some evidence that this scheme have some predictive power in determining people's ability to be successful at various jobs and in other situations. ...
It's 2014. Thousands of professional psychologists have evaluated the century-old Myers-Briggs, found it to be inaccurate and arbitrary, and devised better systems for evaluating personality. Let's stop using this outdated measure — which has about as much scientific validity as your astrological sign — and move on to something else.

Stromberg packs a lot of misinformation into the closing paragraphs of his article. He says that, except for E/I, the Big Five "focuses on entirely different categories" — and I've already pointed out that the leading Big Five psychologists (and authors of the NEO-PI-R) have come to the opposite conclusion.

He says that, "apart from a few analyses finding it to be flawed, virtually no major psychology journals have published research on the test — almost all of it comes in dubious outlets like The Journal of Psychological Type, which were specifically created for this type of research." But, on the contrary, and as further described in the next linked post, professional psychologists have been publishing studies based on the MBTI in independent, peer-reviewed journals — e.g., Journal of Personality, Journal of Personality Assessment, Journal of Personality & Social Psychology, Journal of Research in Personality, Personality & Individual Differences — for more than 40 years.

I don't disagree that, as a matter of degree, the Big Five is more widely used in the academic community than the MBTI, and I assume Big Five supporters can now point to more published studies than MBTI supporters. But Stromberg's claims that the MBTI has been all but ignored (and/or affirmatively rejected) among professional psychologists — and "has about as much scientific validity as your astrological sign" — are way off base.

There are hard sciences, soft sciences and pseudosciences and, unlike astrology, temperament psychology in any of its better-established varieties (including both the Big Five and the MBTI) belongs in the "soft science" category, as further discussed in this post, which includes links that point to quite a lot of scientific support for the MBTI.

What's more, the MBTI really doesn't belong in a substantially different category than the Big Five when it comes to reliability (as already discussed) and validity. The 2003 Bess/Harvey/Swartz study I also link to in that last linked post summed up the MBTI's relative standing in the personality type field this way:

Originally Posted by Bess/Harvey/Swartz In addition to research focused on the application of the MBTI to solve applied assessment problems, a number of studies of its psychometric properties have also been performed (e.g., Harvey & Murry, 1994; Harvey, Murry, & Markham, 1994; Harvey, Murry, & Stamoulis, 1995; Johnson & Saunders, 1990; Sipps, Alexander, & Freidt, 1985; Thompson & Borrello, 1986, 1989; Tischler, 1994; Tzeng, Outcalt, Boyer, Ware, & Landis, 1984). Somewhat surprisingly, given the intensity of criticisms offered by its detractors (e.g., Pittenger, 1993), a review and meta-analysis of a large number of reliability and validity studies (Harvey, 1996) concluded that in terms of these traditional psychometric criteria, the MBTI performed quite well, being clearly on a par with results obtained using more well-accepted personality tests.

...and the authors went on to describe the results of their own 11,000-subject study, which they specifically noted were inconsistent with the notion that the MBTI was somehow of "lower psychometric quality" than Big Five (aka FFM) tests. They said:

Originally Posted by Bess/Harvey/Swartz In sum, although the MBTI is very widely used in organizations, with literally millions of administrations being given annually (e.g., Moore, 1987; Suplee, 1991), the criticisms of it that have been offered by its vocal detractors (e.g., Pittenger, 1993) have led some psychologists to view it as being of lower psychometric quality in comparison to more recent tests based on the FFM (e.g., McCrae & Costa, 1987). In contrast, we find the findings reported above — especially when viewed in the context of previous confirmatory factor analytic research on the MBTI, and meta-analytic reviews of MBTI reliability and validity studies (Harvey, 1996) — to provide a very firm empirical foundation that can be used to justify the use of the MBTI as a personality assessment device in applied organizational settings.

And maybe the most important point to stress on the "MBTI vs. Big Five" issue is that, for an ordinary person, there's really no need to choose one or the other. Assuming that the real underlying temperament dimensions that the MBTI is dealing with (in its imperfect way) are the same as four of the dimensions that the Big Five is dealing with (in its imperfect way), I don't see any reason not to look to respectable Big Five sources and respectable MBTI sources (as I do) for interesting data and possible insights into the nature of those dimensions.

In his final paragraph — the same one that tells us that the MBTI "has about as much scientific validity as your astrological sign" — Stromberg also tells us that "thousands of professional psychologists have evaluated the century-old Myers-Briggs, found it to be inaccurate and arbitrary, and devised better systems for evaluating personality." Thousands! Yikes. If he'd just said "hundreds," I'd say there's no way he could come close to backing that assertion with a list of sources. The fact that he found it appropriate to refer to "thousands" of evaluations arguably tells you all you need to know about his fastidiousness in the factual-accuracy department.

It's enough to make you wonder where the man got his "formal training" in journalism.

The Forer effect

Originally Posted by Stromberg
This isn't a test designed to accurately categorize people, but a test designed to make them feel happy after taking it. This is one of the reasons why it's persisted for so many years in the corporate world, despite being disregarded by psychologists. ...
This is called the Forer effect, and is a technique long used by purveyors of astrology, fortune-telling, and other sorts of pseudoscience to persuade people they have accurate information about them.

I think anyone who points to the MBTI as a good example of the Forer effect can't be very familiar with the MBTI. To go all the way back to its roots, Jung viewed temperament as, to a substantial degree, the source of people's crazinesses and difficulties as much as their strengths. And I'd say all the respectable modern MBTI sources devote a significant amount of attention to the common weaknesses associated with each type.

What's more, because of the MBTI's dichotomous structure, deciding that any particular MBTI preference fits you well involves, by definition, a corresponding decision that the opposite pole doesn't fit you that well. When I read MBTI profiles, I recognize myself in INTJ descriptions, yes, but in reading descriptions of some of the other types, my reaction — far from a Forer effect — is often more along the lines of, yes! those are those people who drive me up the wall, or feel alien to me.

I'm not saying that someone looking to discredit the MBTI as a Forer phenomenon couldn't locate some websites where the descriptions tend to be on the vague and/or rosy side. But that's not typical of MBTI sources, in my experience, and it certainly wasn't Myers' perspective.

Close to half of each type description in the third (most recent) edition of the MBTI Manual is devoted to "Potential Areas for Growth" — i.e., typical weaknesses — for each type. As one example, here's that portion of the INTJ portrait:

Sometimes life circumstances have not supported INTJs in the development and expression of their Thinking and Intuitive preferences.

If they have not developed their Thinking, INTJs may not have reliable ways to translate their valuable insights into achievable realities.

If they have not developed their Intuition, they may not take in enough information or take in only that information that fits their insights. Then they may make ill-founded decisions based on limited or idiosyncratic information.

If INTJs do not find a place where they can use their gifts and be appreciated for their contributions, they usually feel frustrated and may

Become aloof and abrupt, not giving enough information about their internal processing

Be critical of those who do not see their vision quickly

Become single-minded and unyielding in pursuing it

It is natural for INTJs to give less attention to their non-preferred Sensing and Feeling parts. If they neglect these too much, however, they may

Overlook details or facts that do not fit into their Intuitive patterns

Engage in "intellectual games," quibbling over abstract issues ad terms that have little meaning or relevance to others

Not give enough weight to the impacts of their decisions on individuals

Fail to give as much praise or intimate connection as others desire

Under great stress, INTJs can overindulge in Sensing activities – watching TV reruns, playing cards, overeating – or become overly focused on specific details in their environment that they normally do not notice or usually see as unimportant (housecleaning, organizing cupboards).

Predictive power

Originally Posted by Stromberg
[Adam Grant says,] "The characteristics measured by the test have almost no predictive power on how happy you'll be in a situation, how you'll perform at your job, or how happy you'll be in your marriage." ...
Another indicator that the Myers-Briggs is inaccurate is that several different analyses have shown it's not particularly effective at predicting people's success at different jobs.

Whether you're talking about the MBTI or the Big Five, no respectable source is ever going to make the claim that the personality dimensions measured by the typology come remotely close to covering the waterfront when it comes to the multiplicity of factors that can come into play in terms of "how you'll perform at your job," or "how happy you'll be in your marriage." Myers devoted separate chapters of Gifts Differing to "Type and Marriage" and "Type and Occupation," and she certainly didn't display anything like the attitude that the MBTI could be used to reliably predict job performance or marriage success. As one example, she noted that, although the limited evidence she was aware of suggested that birds-of-a-feather marriages were more common than complementary-opposites marriages, each could be successful, while also opining that "understanding, appreciation, and respect" were the main factors that "make a lifelong marriage possible and good" and that "similarity of type is not important, except as it leads to these three." As another example, here's some of what she had to say about type and job choices:

Originally Posted by Myers People should not be discouraged from pursuing an occupation because they are "not the type." When an occupation is seldom chosen by people of their own type, the prospective workers should investigate the job thoroughly. If they still want to pursue it and are willing to make the effort required to be understood by their co-workers, they may be valuable as contributors of abilities that are rare among their co-workers.

In addition, for what it's worth, the official MBTI folks have made it clear they consider it inappropriate and unethical to use the MBTI in connection with hiring, firing, job placement and/or promotions, and also consider it unethical to require any employee to take the MBTI in the first place. As explained on Peter and Katharine Myers' website:

Originally Posted by MBTIComplete
Employers use the Myers-Briggs tool for these purposes:

Training and development of employees and managers

Improving teamwork

Coaching and developing others

Improving communication

Resolving conflicts

Understanding personal styles to maximize effective use of human resources

Determining the organization's type

[...]
Taking the MBTI assessment should always be voluntary. The MBTI tool should be used to inform decisions through discussion, but not used to hire, fire, or promote people. The ethics stated by CPP, Inc., the publisher of the MBTI tool, maintain that individuals should be free to choose whether or not to take the MBTI assessment and to decide with whom to share results.

(For more on the ethical guidelines governing corporate use of the MBTI, see here.)

Buut, on the other hand... Stromberg himself acknowledges that "there's some evidence that [the Big Five factors] have some predictive power in determining people's ability to be successful at various jobs and in other situations." And given that, as previously discussed, the MBTI is essentially tapping into four of the Big Five dimensions, it's pretty silly for somebody to say, on the one hand, that your Big Five type may have some noteworthy predictive power when it comes to job success while simultaneously claiming that your MBTI type has "almost no predictive power" in that regard.

The official MBTI folks put out Career Reports that show the popularity for each type of "22 broad occupational categories," based on "a sample of more than 92,000 people in 282 jobs who said they were satisfied with their jobs." The sample included, e.g., 4,190 INTJs, 4,550 INTPs and 3,230 ISFPs, so it's a huge sample by personality typology standards.

For anyone unfamiliar with the psychometric standard of "validity": In the modern world of personality typology, the relevant scientific standards include judging typologies in terms of two broad criteria known as reliability and validity. Reliability basically has to do with internal consistency (as previously discussed), while validity basically relates to the extent to which the theoretical constructs seem to line up with actual things out there in the real world that the typology test items don't directly ask the subjects about.

I've managed to find free sample Career Reports for about three-quarters of the types from that 92,000-subject pool, and I'd say the statistics seem to offer pretty dramatic support for the notion that someone's MBTI type has a substantial impact on their job choices and job satisfaction — and with the S/N preference playing a particularly large role (consistent with both Myers' and Keirsey's perspectives). The more preferences two types share, the more likely it appears to be that they'll favor the same job families. As an example, the next spoiler shows the "Most Attractive Job Families" (= scores above 60) for INTJs and INTPs:

INTJs
Life, Physical, and Social Sciences [100]

Biologist, chemist, economist, psychologist

Architecture and Engineering [92]

Architect, surveyor, mechanical engineer, chemical engineer

Computers and Mathematics [76]

Programmer, systems analyst, database administrator, mathematician

Legal [65]

Lawyer, arbitrator, paralegal, court reporter

INTPs Life, Physical, and Social Sciences [100]

Biologist, chemist, economist, psychologist

Computers and Mathematics [88]

Programmer, systems analyst, database administrator, mathematician

Arts, Design, Entertainment, Sports, and Media [85]

Artist, coach, musician, reporter

Architecture and Engineering [77]

Architect, surveyor, mechanical engineer, chemical engineer

Legal [72]

Lawyer, arbitrator, paralegal, court reporter

And, by contrast, the next spoiler shows the "Most Attractive Job Families" (= scores above 60) for ISFPs:

ISFPs
Health Care Support [100]

Nurse's aide, veterinary assistant, pharmacy aide, physical therapy aide

Architecture and Engineering [91]

Architect, surveyor, mechanical engineer, chemical engineer

Food Preparation and Service [78]

Chef, food service manager, bartender, host/hostess

Office and Administrative Support [78]

Bank teller, receptionist, clerical services, legal secretary

Building and Grounds Maintenance [75]

Gardener, tree trimmer, housekeeping, lawn service supervisor

Transportation and Materials Moving [66]

Pilot, air traffic controller, driver, freight handler

Personal Care and Service [64]

Lodging manager, personal trainer, hairdresser, child care provider

I'd certainly agree that somebody's type shouldn't play an oversize role in choosing a career, and (consistent with Myers' perspective) certainly shouldn't be allowed to override somebody's strong sense, based on other factors, that they'd enjoy a job that's not particularly typical for their type. But does being an INTJ or ISFP basically say as little about the probability that someone will end up enjoying a job in the Food Preparation and Service or Computers and Mathematics area (respectively) than someone's astrological sign? Are you kidding me?

Beyond the metrics

Here's some recycled reckful from last year:

Originally Posted by reckful For an ordinary person looking for a typology to help them understand how the personality components that the MBTI and Big Five tap into ... combine to form multiple relatively distinct personalities, and looking for rich descriptions of those personalities, I don't think there's any question that the Big Five can't really compete with the MBTI. There's no Big Five equivalent of Jung's Psychological Types or Myers' Gifts Differing or Keirsey's Please Understand Me or any of the other reasonably well-regarded MBTI sources that are aimed at non-academics. And yes, the descriptions in those kinds of Jungian/MBTI sources go well beyond the kinds of limited descriptions that can (at least arguably) be backed by one or more peer-reviewed studies — but, unless and until the day comes when a lot more studies have been done, I think anyone who simply dismisses all those less-than-fully-"scientific" sources is missing out on a lot.

Stromberg cites organizational psychologist (and HuffPost blogger) Adam Grant several times, and Grant posted a similar MBTI "debunking" a few months ago, but Grant himself later ended up acknowledging that he "mostly agreed" with the "thought-provoking comments" in this rebuttal by organizational consultant Hile Rutledge to Grant's article.

In his rebuttal, Rutledge noted that, as part of his organizational development work, he's used both the MBTI and the Big Five (as well as several other psychometric tools) and found them both useful. But he also explained that, "in my 20+ years as an organization consultant, I have come to see plainly that the real client work is not about the tool, but instead about using these tools to help increase client self-awareness so that they can more effectively manage themselves" — and he went on to say:

Originally Posted by Rutledge
What I like best about the Myers-Briggs tool and its underpinning model ... is that it speaks to personal preferences and not to specific skills, performance or ability. Ironically, one of Grant’s sharpest criticisms of the MBTI assessment is perhaps the thing that has made (and kept) the tool so popular for so long: the Myers-Briggs Type Indicator never claims to indicate what I do well. It never indicates what job I should take or what partner I should choose. For these reasons, metric-centric folks claim the MBTI assessment does not give us "outcomes that matter."
On the contrary — I believe (as have millions of Type users over many decades) that the MBTI assessment is a tool of self-awareness. ... It does not try to predict what we will do next or who will succeed or fail in any given endeavor. What it does do instead is indicate what may be my preferred way of gathering information in the world and my innately preferred way making decisions about that information. It also indicates where I tend to energize as well as the behavioral face I prefer to show the world. ...
Adam Grant and professionals like him want tools to measure, rank, predict and select. These are all fine things to want, but if that is what he is after, he is right to avoid the MBTI assessment. If, however, Mr. Grant is ever in the market for a client-centered tool that builds self-awareness and helps lead to better self-management and growth, he would be hard-pressed to find a better option than the MBTI. ...
Since [the MBTI] became publicly accessible in the mid 1970s, it has become (and remains) the most popular personality assessment tool in the world. "Fads" don’t last forty years. The MBTI is here to stay. And, unfortunately, so are those who would prefer the work of personal self-awareness and development to be constrained and defined by metrics, rather than merely informed by them.

Dichotomies vs. functions

Having pointed to a lot of scientific support for the MBTI, and especially given how popular the so-called "cognitive functions" are on MBTI-related internet forums, it behooves me to note that the data support for the MBTI relates almost exclusively to the four MBTI dichotomies — which, as already discussed, substantially line up with four of the Big Five dimensions — rather than the eight functions. As I understand it, and as further discussed in this long INTJforum post, the few attempts to test/validate the functions — and, in particular, the functions model most often discussed on internet forums (where INTJ = Ni-Te-Fi-Se and INTP = Ti-Ne-Si-Fe) — have not led to a respectable body of supporting results.

Links in INTJforum posts don't work if you're not a member, so here are replacements for two of the links in that post:

McCrae & Costa article (click on the pic on the right to access the full article)
Reynierse article

Want moar?

For anyone who's interested, here's another long — and reasonably good — critical review of Stromberg's article.