The main problem with MBTI

[Olm the Water King]

The Myers-Briggs Personality Test

From the perspective of statistical analysis, the MBTI's fundamental premise is flawed. According to Myers & Briggs, each person is either an introvert or an extravert. Within each group we would expect to see a bell curve showing the distribution of extraversion within the extraverts group, and introversion within the introverts. If the MBTI approach is valid, we should expect to see two separate bell curves along the introversion/extraversion spectrum, making it valid for Myers & Briggs to decide there are two groups into which people fit. But data have shown that people do not clump into two separately identifiable curves; they clump into a single bell curve, with extreme introverts and extreme extraverts forming the long tails of the curve, and most people gathered somewhere in the middle. Jung himself said "There is no such thing as a pure extravert or a pure introvert. Such a man would be in the lunatic asylum." This does not support the MBTI assumption that people naturally separate into two groups. MBTI takes a knife and cuts the bell curve right down the center, through the meatiest part, and right through most people's horizontal error bars. Moreover, this forced error is compounded four times, with each of the four dichotomies. This statistical fumble helps to explain why so many people score differently when retaking the test: There is no truly correct score for most people, and no perfect fit for anyone.

Discuss.

 

[á´…eparted]

This is a very good observation. It's actually quite rare for their to be camel hump distrubutions, and honestly I don't think I've ever seen a credible one in any sort of personality theory. That said I don't think a gaussian distrubution somehow invalidates type theory, but it does beg the question if it sort of misses the bulk of the human condition.

Within MBTI itself, I am very strongly E, and very strongly J, so in those realms it fits me really well and I have never really brought it's validity into question. In effect, I am a rarity in those two areas based off a gaussian distrubution. However I am only weakly N, and weakly F, and in those areas I feel they sort of both "miss the mark" and don't really capture things. I'm in the middle with those and in effect "normal", and it seemingly makes MBTI fail, which is sort of a theory of extremes. Not in the literal sense, but it seems to seek to categorize individuals who fall on far ends of the spectrum, and those individuals aren't common.

 

[Bush]

Though you could get around the whole "it's not binomial" thing by pointing out that the test is measuring "Clarity of preference." That is, that everyone does have a preference for one or the other, but the test can only make it so clear.

There's no real reason why clarity would have to follow a binomial. Clarity itself just might follow a normal. Who knows? The theory doesn't say. Could be anything.

Not that I'm defending the thing because I believe all of that. You'd expect clarity to also follow a binomial. But since clarity is an indirect measure, you've at least put up a layer between MBTI and the whole "binomial" point if you invoke it.

(I'm personally N hardcore, and everything else for me is near middling; especially E. On the test, at least.)

 

[evilrubberduckie]

Im a strong E and a Strong P.

My T is the lowest stat, so I can unconsiously switch between F and T.

my childhood environment forced me to be aware of my Sensing function. Even then My preference for N dominated what is a mature(ish) Se.

So I feel like my T and F are "camel bumps"

 

[reckful]

The Myers-Briggs Personality Test
...
Discuss.

Ugh. That post you linked to is woefully uninformed about multiple MBTI issues, including the "bimodal" vs. "bell curve" issue.

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 interested in reading about the validity of the MBTI — and about a number of other other issues often raised by people claiming to "debunk" the MBTI — will find a lengthy two-post discussion starting here.

That post includes a discussion of the "bimodal distribution" issue, and I've copied that part of it into the spoiler at the end of this post.

But the whole two-part linked post is well worth a read — and is especially recommended as an antidote for anybody who made the mistake of reading the entire article linked in the OP.

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.

 

[Olm the Water King]

[MENTION=18736]reckful[/MENTION] that's interesting. I'm gonna give it some more thought.

However, one thing that you haven't addressed at all is that unlike MBTI, the Big Five doesn't give you a hierarchical representation of "functions" which pair introversion/extraversion with S, N, F or T. It just shows your traits in %. MBTI, on the other hand, would have me believe that, if I am an INFP, my functions are, in order of preference, Fi - Ne - Si - Te, etc...

Now here's the problem. If I actually take a test that measures my preference for functions, this is what happens. Fi is my first function. That's all well so far. However, my second function is Fe.

How does that even work? There is no MBTI type whose first function is Fi and second is Fe. In fact, if my primary function is Fi, then Fe should be nowhere in my first 4.

Keeping all this in mind, then for example the difference between scoring 40% or 60% in MBTI extraversion or between 40% and 60% in Big Five extraversion is much more significant than you seem to be implying.

When it comes to functions, the bimodal vs bell curve seems quite important to me. And it's because of this that the Big Five is fundamentally different from both MBTI and Socionics.

 

[miss fortune]

I was just complaining about how the whole E/I thing always seems a bit nebulous to me with most people yesterday!

I fall pretty directly in the center on that (and on the S/N continuum as well... T and P are both quite strong)... I'm really not very social, though once dragged out I can be pleasant and chatty if I feel like it (or I can spend the entire evening just watching my surroundings like a predator... it just depends). All of the preferences are more of bell curves than black and white dichotomies and people tend to make the mistake of thinking that they are something like a light switch instead of a gradual slide.

of course, if you asked me what the biggest problem of the MBTI was, I'd say it was the people who are interpreting it and using it incorrectly

 

[highlander]

I don't understand the OP.

If you believe in a dichotomies based approach, with respect to I/E, I thought I heard that is the one thing there IS proof of (a tendency towards introversion or extraversion) including a genetic link. Proof aside, it isn't too difficult to observe in everyday life there are some people who are far more outgoing and others who are more reserved. For anyone who has had children, it seems also pretty obvious that a preference for introversion or extraversion manifests at a pretty early age.

As to a functions based approach, all it takes is for one to have a preference for two cognitive functions in order - just the top two really. It's a preference for a way of thinking. I don't see how the existence (or lack of existence) of those preferences need to tie to camel humps or a bell curve.

 

[miss fortune]

As to a functions based approach, all it takes is for one to have a preference for two cognitive functions in order - just the top two really. It's a preference for a way of thinking. I don't see how the existence (or lack of existence) of those preferences need to tie to camel humps or a bell curve.

function based, I end up having to sort out by lower things in the order, since my top scores are rather muddled up with each other

 

[Olm the Water King]

I don't understand the OP.

If you believe in a dichotomies based approach, with respect to I/E, I thought I heard that is the one thing there IS proof of (a tendency towards introversion or extraversion) including a genetic link. Proof aside, it isn't too difficult to observe in everyday life there are some people who are far more outgoing and others who are more reserved. For anyone who has had children, it seems also pretty obvious that a preference for introversion or extraversion manifests at a pretty early age.

As to a functions based approach, all it takes is for one to have a preference for two cognitive functions in order - just the top two really. It's a preference for a way of thinking. I don't see how the existence (or lack of existence) of those preferences need to tie to camel humps or a bell curve.

So what would you say my type is if my first preference is Fi and my second is Fe?

 

[miss fortune]

So what would you say my type is if my first preference is Fi and my second is Fe?

In my case, I have to sort things out with the functions lower down on the totem pole... as in my Fi sucks and my Si is quite a bit worse than my Ni is, so that leads to some conclusions

 

[Olm the Water King]

One more thing about the fuctions, and perhaps this is actually more important than what I've written so far: What exactly are they? When I am 'using Fi', what is happening in my brain? Which parts are active (or at least *more* active)? And how is this different from using Fe or using Ti?

Also, is it actually possible to separate them? When I am thinking about my internal values and I feel something regarding them, am I using only that particular "arrangement" that would be described as Fi? Am I not also feeling something like Fe? My values are also about caring for others and social harmony. And when I think about this, I am using a lot of concrete data as well...Which would be more like Si? And what if I was only using Si in this moment? How does that even work on a neural level?

Do MBTI functions actually exist?

 

[highlander]

So what would you say my type is if my first preference is Fi and my second is Fe?

I would say that you are heavy on judging without a lot of perceiving .

 

[reckful]

[MENTION=18736]reckful[/MENTION] that's interesting. I'm gonna give it some more thought.

However, one thing that you haven't addressed at all is that unlike MBTI, the Big Five doesn't give you a hierarchical representation of "functions" which pair introversion/extraversion with S, N, F or T. It just shows your traits in %. MBTI, on the other hand, would have me believe that, if I am an INFP, my functions are, in order of preference, Fi - Ne - Si - Te, etc...

Now here's the problem. If I actually take a test that measures my preference for functions, this is what happens. Fi is my first function. That's all well so far. However, my second function is Fe.

How does that even work? There is no MBTI type whose first function is Fi and second is Fe. In fact, if my primary function is Fi, then Fe should be nowhere in my first 4.

Keeping all this in mind, then for example the difference between scoring 40% or 60% in MBTI extraversion or between 40% and 60% in Big Five extraversion is much more significant than you seem to be implying.

When it comes to functions, the bimodal vs bell curve seems quite important to me. And it's because of this that the Big Five is fundamentally different from both MBTI and Socionics.

Dario Nardi's functions test is arguably the most-linked-to cognitive functions test, but as further discussed in the spoiler in this post, INTJs typically get high Te scores and high Ti scores (with Te not substantially favored over Ti), when they take Nardi's test. They also get high Ni scores and high Ne scores (with Ni not substantially favored over Ne). And INFJs often get Fi scores that are as high or higher than their Fe scores. And all the IN types tend to relate pretty strongly to Ti. And so on. As I understand it, there has never been a cognitive functions test where the results come anywhere close to lining up with the Harold Grant model.

The Harold Grant function stack — the one that says INFP=Fi-Ne-Si-Te — is inconsistent with both Jung and Myers, has never been endorsed by the official MBTI folks, has no respectable body of evidence behind it, and should really be considered all but disproven at this point. And I think James Reynierse is correct to have concluded that the functions themselves are a "category mistake" that have no validity other than the piggybacked validity they end up with when, e.g., an "Si" description is put together that describes stuff that's characteristic of SJs, and is then found to apply reasonably well to people who purportedly "use Si" as their dominant or auxiliary function (because, duh, they're SJs).

If you're interested in quite a bit more input from me on the relationship between the dichotomies and the functions, the place of the functions (or lack thereof) in the MBTI's history, and the tremendous gap between the dichotomies and the functions in terms of scientific respectability — not to mention the unbearable bogosity of the Grant function stack — you'll find a lot of potentially eye-opening discussion in the long spoiler at the end of this post and the posts linked to at the end of that spoiler.

 

[highlander]

Dario Nardi's functions test is arguably the most-linked-to cognitive functions test, but as further discussed in the spoiler in this post, INTJs typically get high Te scores and high Ti scores (with Te not substantially favored over Ti), when they take Nardi's test. They also get high Ni scores and high Ne scores (with Ni not substantially favored over Ne). And INFJs often get Fi scores that are as high or higher than their Fe scores. And all the IN types tend to relate pretty strongly to Ti. And so on. As I understand it, there has never been a cognitive functions test where the results come anywhere close to lining up with the Harold Grant model.

Yes, I have often thought there should be a better assessment. I think I could make a better one . Maybe some day...

 

[Olm the Water King]

[MENTION=18736]reckful[/MENTION] interesting. I'll check it out.

Hmm..If what you're saying about functional stackings is true, then that means that even if we look at MBTI supporters, practically 95% of them are getting it wrong. Interesting.

 

[Poki]

That analysis based off of the fact someone is deemed extrovert and introvert is retarded in my opinion. It's a "generally" thing. I am generally introverted, it doesn't mean I have no extroversion. The pure fact that half my stack is introverted and half extroverted shows that this camel hump doesn't even apply. If it were as extreme as this argument states I would be Ti Si Ni Fi not Ti Se Ni Fe.

 

[Jaguar]

So what would you say my type is if my first preference is Fi and my second is Fe?

Dr. Allen Marshall came up with a theory similar to Beebe's, only his theory is that the functions are linked.
That means if one first developed Ne, Ni will come next.

Type development/preference can be like blood pressure: One person can walk around perfectly fine at 90/60, whereas another can be unable to even walk. So for those who think they have an unusual set of preferences, they may serve the individual quite well. For another, it could be a disaster. It amazes me how so many have deemed individuals unhealthy or claim a pattern is impossible unless they properly fit into a predefined jello mold created by an "expert."

From the MBTI manual by Isabel Briggs Myers, Mary H. McCauley, Naomi L. Quenk and Allen L. Hammer:

In dealing with people, when we keep their type in mind, we are respecting not only their abstract right to develop along lines of their own choosing but also the importance of qualities they have developed by making that choice. For example, if, for whatever reason, they have not exercised one or more of their preferences, they may not have developed a type, or at least a type that they can report clearly. Not everyone is a type.

 

[INTP]

MBTI measures jungian functions(and we have both I and E functions), therefore I/E should be measured as two separate scales(or actually two E scales and two I scales) if you want to see the real results. However since MBTIs type code is portrayed with one letter for I or E, it needs to be cut from somewhere to separate the two types. With MBTI the cut is done based on dominant function, not traits like sociability etc put on scale like big 5 for example does.
So yes, you cant put MBTI types on bell curve properly by type, but i dont think its a flaw in MBTI itself, its just that MBTI is too complex for it to be put on one statistical measurement, or well you can do that, but it might put some introverts on the E side of the curve(I dom function barely stronger than aux and low tert with high inferior could cause this) and have all sorts of other problems.