The Myers-Briggs Personality Test

A critical look at the world's most popular psychological metric, the Myers-Briggs Type Indicator.

by Brian Dunning

Filed under Fads, General Science

Skeptoid #221
August 31, 2010
Podcast transcript | Listen | Subscribe

Today we're going to delve into the murky depths of Jungian psychology, and examine one of its most popular surviving manifestations. The Myers-Briggs test is used all over the world, and is the single most popular psychometric system, with the full formal version of the test given more than 2,000,000 times a year. But is it a valid psychological tool, is it just another pop gimmick like astrology, or is the truth somewhere in between?

The Myers-Briggs Type Indicator, called MBTI for short, more properly owes the bulk of its credit to the great Swiss analytical psychologist Carl Jung. In 1921, Jung published his book Psychological Types, in which he laid out all the same concepts found in the MBTI, but he had them organized quite differently. Jung had everyone categorized as either a "perceiver" or a" judger". Perceivers fell into one of two groups: sensation and intuition; while judgers also fall into two groups: thinking and feeling. So everyone fits into one of those four buckets. Finally, each bucket is divided into two attitude types: introversion and extraversion. Thus, the scale proposed by Jung divided us all into one of eight basic psychological types.

An American woman, Katherine Briggs, bought Jung's book and was fascinated by it. She recommended it to her married daughter, Isabel Briggs Myers, who had a degree in political science. The two of them got hooked on the idea of psychological metrics. Together they sat down and codified their own interpretation of Carl Jung, making a few important changes of their own. Jung had everyone fitting into one of four basic buckets. Myers and Briggs decided that each person probably combined elements, so they modified Jung's system and made it a little more complex, ending up with four dichotomies, like binary switches. Any combination of the four switches is allowed, and Myers and Briggs reasoned that just about every personality type could be well described by one of the sixteen possible ways for those switches to be set. Basically, according to Myers and Briggs, we're all represented by a four-digit binary number.

The basic test, of which there are several variations and revisions, is called the MBTI Step I and it's a series of almost 100 questions, each with two possible answers. Each question consists of two short statements or word choices, and you simply choose which of the two you prefer. When the results are tabulated, you should ideally have your preference established for each of the four dichotomies; and congratulations, you are now identified by one of sixteen possible personality types. Myers and Briggs gave names and descriptions to all sixteen, names such as the Executive, the Caregiver, the Scientist, and the Idealist.

Perhaps the most common misconception about the MBTI is that it shows your aptitude, helping you determine what kinds of things you'd be good at. This is not the case. Myers-Briggs is only about determining your preference, not your ability. There might be things that you're good at that you don't enjoy, and there might be things you enjoy that you're not good at. The MBTI helps your find your comfort zone, the types of activities you'll like and be most content with; not necessarily those at which you'll be especially competent.

Even though neither had any background in psychology, Myers and Briggs enjoyed great success with their system. As Mrs. Briggs was getting quite old, Isabel Myers was the main driving force. Her initial idea was that certain personality types would more easily excel at different jobs, and the tool was intended to be used by women entering the workforce during World War II. However, it was not published until 1962, but since that time, it's become the most widely used basic psychology test. It's most often used outside of the psychological profession, and is employed in career counseling, sports coaching, marriage counseling, dating, professional development, and almost every other field where people hope to be fit with a role that would work best for them.

So the MBTI's practical use is overwhelmingly unscientific, and it's often criticized for this. Criticism ranges from the pragmatic fact that neither Jung nor Myers and Briggs ever employed scientific studies to develop or test these concepts, relying instead on their own observations, anecdotes, and intuitions; all the way to charges that your MBTI score is hardly more meaningful than your zodiac sign.

One obvious trait that the MBTI has in common with horoscopes is its tendency to describe each personality type using only positive words. Horoscopes are so popular, in part, because they virtually always tell people just what they want to hear, using phrases that most people generally like to believe are true, like "You have a lot of unused potential." They're also popular because they are presented as being personalized based on the person's sign. This has been called the Forer Effect, after psychologist Bertram Forer who, in 1948, gave a personality test to his students and then gave each one a supposedly personalized analysis. The impressed students gave the analyses an average accuracy rating of 85%, and only then did Forer reveal that each had received an identical, generic report. Belief that a report is customized for us tends to improve our perception of the report's accuracy.

I notice this right away when I read Isabel Myers' description for my own personality type, ISTJ, the Duty Fulfiller: "Practical, matter-of-fact, realistic, and responsible." Basically it's a nice way to say "Dry, boring, and punctual," which hits my nail pretty squarely on the head. From that alone, I might conclude that the MBTI is extraordinarily insightful. But if I look at her description of my opposite counterpart, an ENFP, the Inspirer, that person is "Warmly enthusiastic and imaginative. Sees life as full of possibilities." Who wouldn't like to believe that about his or her self? If I'd taken the test and been handed that result, I might be equally inclined to embrace it, probably thinking something like "Wow, I'm even more awesome than I thought I was."

Due to these legitimate criticisms of the MBTI and its unscientific underpinnings, the test is rarely used in clinical psychology. I did a literature search on PubMed and discovered that, interestingly, many of the published studies of its practical utility come from nursing journals. Many of the other publications pertain to relationship counseling and religious counseling. Normally, this is a red flag. When you see a topic that purports to be psychological being used in practically every professional discipline except psychology, you have very good reason to be skeptical of its actual value. Should we dismiss the Myers-Briggs Type Indicator as a psychometric?

The test does have some severe inherent problems. It's been found that 50% of test takers who retake it score differently the second time. This is because nobody is strictly an E or an I, for example, but somewhere in between. Many people are right on the border for some of the four dichotomies, and depending on their mood that day or other factors, may answer enough questions differently to push them over. Yet the results inaccurately pigeonhole them all the way over to one side or the other. This makes it possible for two people who are very similar to actually end up with completely opposite scores. Isabel Myers was aware of this limitation, and did her best to eliminate questions that did not push people away from the center when the results were studied in aggregate. It was a hack.

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.

Tip Skeptoid $2/mo $5/mo $10/mo One time

And this has been borne out in observation. A number of studies have found that personality types said to be most appropriate for certain professions, notably nursing or teaching, turn out to be no more prevalent among that profession than among the general population. The Army Research Institute commissioned one such study to determine if the MBTI or similar tests could be used to improve the placement of personnel in different duties, and firmly concluded that the results of such tests did not justify their use in career counseling.

From reviewing the literature, I do find one common theme among mainstream psychotherapists where the use of the MBTI is advised, and that's as a conversation starter. It's a fine way to give people a quick snapshot of what their strengths and weaknesses might be, and of those with whom they interact. To get the dialog going, this is a perfectly valid tool. But as a tool for making career decisions, relationship decisions, or psychiatric assessment, no. Although it would be nice to have a magically easy self-analysis tool that can make your decisions for you and be your crystal ball, the Myers-Briggs test is not it. It is interesting and it does have value as a starting point for meaningful dialog, but that's where the line should be drawn.

Brian Dunning

© 2010 Skeptoid Media Copyright information

References & Further Reading

Dickson, D., Kelly, I. "'The Barnum Effect' in Personality Assessment: A Review of the Literature." Psychological Reports. 1 Feb. 1985, Volume 57, Number 2: 367-382.

Druckman, D., Bjork, R. In the Mind's Eye: Enhancing Human Performance. Washington, DC: National Academy Press, 1991.

Howes, R., Carskadon, T. "Test-Retest Reliabilities of the Myers-Briggs Type Indicator as a Function of Mood Changes." Research in Psychological Type. 1 Jan. 1979, Volume 2, Number 1: 67-72.

Jung, C. Psychological Types. New York: Harcourt, Brace & Company, Inc., 1923.

Long, T. "Myers-Briggs and Other Modern Astrologies." Theology Today. 1 Oct. 1992, Volume 49, Number 3: 291-295.

Myers, Isabel and Peter. Gifts Differing. Palo Alto: Consulting Psychologists Press, 1980.

Reference this article:
Dunning, B. "The Myers-Briggs Personality Test." Skeptoid Podcast. Skeptoid Media, 31 Aug 2010. Web. 4 Oct 2015. <>


10 most recent comments | Show all 139 comments

Vicki, I am not into astrology either.

I was exposed to this in 98 and treated it as an exercise to critical thinking.

It worked.

I am not into card reading, I am not into having someone pin me down from a simplistic test of how I interact with a simplistic test.

I do note that;
1) psychopathy, whilst overwhelming in the population, isnt tested for.
2)equal opportunity mandated by western work forces is not catered for.

The trial data is as weak as other such candy floss endeavours in fringe psychology parametrics.

Mind you, I was labeled as someone starting with an E.

I think that is someone who just bothered to take stats and..gasp.enjoyed it immensely

Moral Dolphin Back in Mud Suit, Greenacres by the sea Oz
June 4, 2013 7:25pm

I used to work in customer service at CPP, the company that publishes the MBTI (as well as several other instruments), so this episode beckoned to me when I first discovered these podcasts a few weeks ago.

It seemed to me that Brian presented a fair overview and assessment in such a short piece, and I'm pretty comfortable agreeing with his conclusion, given my own experience.

As a phone rep who spoke with 70-90 customers daily, explaining the tests & forms to everyone from variously accredited psychologists to schools and government agencies, I was encouraged to take all the tests multiple times (in addition to attending frequent training sessions). It definitely made for entertaining happy hour discussions with fellow CS reps after work, and it was fun to sit around trying to guess friends' and family's types, but I never found the career or team applications all that convincing.

I actually found my placement on each scale of the four dichotomies to be interesting and generally consistent (despite a few maddeningly worded questions I always wanted to answer with "it depends"), but the final summary that lumped them all together into one "personality type" always seemed forced and artificial.

In retrospect, that was the aspect that seemed truly "horoscope-y" to me. While exploring the four spectra of the basic tendencies can be thought-provoking, the descriptions of the overall types strike me as problematic and basically useless generalizations.

Kate, Californian in Italy
September 26, 2013 4:06am

Thanx Kate for posting that.

Its a good evaluation of the practice and deserves expanding into a longer essay elsewhere.

The practice does deserve the derision that astrology vied so hardly for.

I think blood sugar sucker fish would be a great thesis for the RHCP....

Magnetic Dowser, Pho's diner, Greenacres by the Sea
September 30, 2013 4:15pm

Everything is a placebo. Belief in God, Learned Optimism are, for the most part, only placebos. The "placebo trick" is the magic with which we can endure the hardships and the meaningless of the life. Each person chooses his or her own placebos that fit him or her. Psychology is the "science of placebos." There are no treatments, only rituals. The best psychologists are the ones that deliver the best placebos for their "patients". If the MBTI "works" for some, they should go with it. Others will continue searching until they find the placebo that works for them.

Dan, Vermont
March 8, 2014 2:31pm

I think you make a good point about it being a good conversation starter. But I'm not aware of anyone who takes it as seriously as you indicate. The way I was taught about the MBTI is that it estimates one's preferences in four categories and it's not an "either/or" scenario, it's about where you lean. Now, that it deals with imprecise outcomes certainly makes it unscientific. I don't dispute that.

I was 18 when I first took it and got INT, but my final letter was exactly a 50/50 split between J/P. I've taken it probably about 5 times since then...most recently a year ago, and have gotten INTJ consistently. While it is undeniably unscientific, I do think there's value in people measuring their preferences in these categories. If you prefer perceiving through iNtuition, you're going to be well-practiced but you may also place too much emphasis on it. That is how the purpose of the MBTI was presented to me - as a way to know your preferences and learn to be a well-rounded individual....but that's just what an INTJ would say.

Jim, Pittsburgh
June 10, 2014 12:43pm

What sells people on the MBTI is that it "hits the nail on the head". Of course it does. By answering the questions, you are self-identifying the category you most relate to. It is kind of like a phony psychic (is that an oxymoron?) who repeats back everything you say. Your zodiac sign would be just as accurate if it was selected based on your preferences rather than your birth month.

rh, minneapolis
August 1, 2014 11:59am

This article does virtually nothing to adequately criticise MBTI. It makes no mention of the psychological functions of the types (eg: Fe: Extraverted Feeling, Fi: Introverted Feeling, Te: Extraverted Thinking, Ti: Introverted Thinking, Ne: Extraverted Intuition, Ni: Introverted Intuition, Se: Extraverted Sensing, Si: Introverted Sensing), but only the four letters, hence making it more of a critique of the watered-down, overly-simplistic version of MBTI that is the Keirsey Temperament Sorter... not MBTI; leading me to the conclusion that you have not looked into MBTI deeply enough to be able to give any real, relevant critique of it.
You say "It's been found that 50% of test takers who retake it score differently the second time. This is because nobody is strictly an E or an I, for example, but somewhere in between". You fall into the common misconception many people fall into who are new to MBTI, essentially confirming your ignorance of the underlying psychological functions of the types. Had you known of the functions of the types, you would have understood that every type has two introverted functions and two extraverted functions... basically meaning that MBTI acknowledges that every person does in fact have an introverted and an extraverted side, regardless of whether they are predominantly introverted or extraverted. Every extravert has a secondary (2nd) and inferior (4th) introverted function, and every introvert has a secondary and inferior extraverted function.

Joseph Richardson, Liverpool, England, United Kingdom
October 5, 2014 7:47pm

You're also taking those very basic tests that are floating around far too seriously, which are made by all kinds of different people. A lot/all of those tests are not reliable at all... they should merely serve as a starting point to discovering and narrowing down what your type actually is. Only you can truly identify what your type actually is though a combination of introspection and research of the different types and functions. Just because the tests can be inaccurate does not mean the theory is.

I'll agree to some extent with the point you made, that with some it may determine only a person's preference and not always necessarily their ability to that preference... but I'll make the assertion that anyone who identifies and lives accordingly to their preferences is much more likely to become better at it than things that are not, despite their initial innate levels of ability.

Joseph Richardson, Liverpool, England, United Kingdom
October 5, 2014 7:56pm

You go on to make the assertion that MBTI is "overwhelmingly unscientific", though the only point that was made to support that assertion was "Jung nor Myers and Briggs ever employed scientific studies to develop or test these concepts, relying instead on their own observations, anecdotes, and intuitions". I really have no idea what kind of scientific study you have in mind, if any, that should be employed to fully test this theory... observations and intuitions have always been, for the most part, at the heart of psychology... and I'm pretty damn sure that observations (and there have been a lot in terms of MBTI research) are, in fact, a huge part of science in general as well, and intuitions based on observations are the very things that create theories which, if accurate, can lead to discoveries unimagined by anyone before.
It's only recently that we've been able to begin developing methods and technology to study and understand the human brain, so perhaps at some point a more comprehensive and scientifically proven standard of personality type could be developed, which may either prove and build upon what MBTI has identified, disprove certain elements, or perhaps disprove MBTI altogether. Until that day, MBTI seems to be the most effective tool there is in identifying personality type.

I'd suggest to anyone that before asserting any critique of MBTI, that they should first at the very least read Isabel Briggs Myers' book "Gifts Differing: Understanding Personality Type".

Joseph Richardson, Liverpool, England, United Kingdom
October 5, 2014 7:59pm

I appreciate Joseph's comments, particularly the first two, which are in line with what I was thinking as I read the article. Although the MBTI is indeed worthy of critique, it would be most helpful if those critiquing it had a deeper understanding of it in the first place. I'm also curious what Joseph's personality type is. I identify most as INTP; the other comments I agreed with in this thread were from people who identify as INTJs; it is interesting to note which personalities have a deeper understanding of this and care to look into its personal value regardless of its scientific status. [I tend to think of it more as a philosophy or thought framework rather than a psychology/science.]

Star, USA
January 5, 2015 2:58pm

Make a comment about this episode of Skeptoid (please try to keep it brief & to the point).

Post a reply


What's the most important thing about Skeptoid?

Support Skeptoid

The Flying Saucer Menace
Skeptoid #486, Sep 29 2015
Read | Listen (12:29)
Holocaust Denial
Skeptoid #485, Sep 22 2015
Read | Listen (12:54)
More Unsung Women of Science
Skeptoid #484, Sep 15 2015
Read | Listen (12:56)
Unsung Women of Science
Skeptoid #483, Sep 8 2015
Read | Listen (13:13)
Sir Franklin's Cannibals
Skeptoid #482, Sep 1 2015
Read | Listen (12:13)
#1 -
The St. Clair Triangle UFO
Read | Listen
#2 -
Tube Amplifiers
Read | Listen
#3 -
Read | Listen
#4 -
That Elusive Fibromyalgia
Read | Listen
#5 -
SS Iron Mountain
Read | Listen
#6 -
A Skeptical Look at the News
Read | Listen
#7 -
The War of the Worlds Panic Broadcast
Read | Listen
#8 -
Ancient Astronauts
Read | Listen

Recent Comments...

[Valid RSS]

  Skeptoid PodcastSkeptoid on Facebook   Skeptoid on Twitter   Brian Dunning on Google+   Skeptoid on Stitcher   Skeptoid RSS

Members Portal


Follow @skeptoid

Tweets about skeptoid

Support Skeptoid

Email: [Why do we need this?]To reduce spam, we email new faces a confirmation link you must click before your comment will appear.
characters left. Abusive posts and spam will be deleted.