I first came across the Myers-Briggs Type Inventory (MBTI) around 30 years ago. The MBTI was developed by Isabel Myers, a layman, and her mother Katherine Briggs, around the middle of the twentieth century. They developed a questionnaire that classified people into 16 types based on Carl Jung’s theory of psychological types, along with their own considerable experience of observing people in action, and some inspirational speculation. Jung’s theory was based on differences in the way that we prefer to use our mental capacities to function in the world – and Myers and Briggs simplified this to identify four dimensions of functioning preferences. Their questionnaire and most others classify people’s preferences on these four dimensions and assign a letter based to each dimension based on which side of the middle-point you fall. The combinations of these letters result in 16 so-called “personality types”.
The Myers-Briggs Type Inventory (MBTI) has become extremely popular and is a very widely used tool in management training. There are many variants of the questionnaire and of the type classification available for free online, as well as copyrighted versions used by management training companies and others. It is estimated that since the 1960s, when the test began to be rolled out across the corporate world, more than 50 million people around the world are estimated to have taken it (A).
There are many free online variants of the MBTI, of varying quality. I give links to several that I have found useful.
Kiersey temperament sorter https://profile.keirsey.com/#/b2c/assessment/start?partid=0
Humanmetrics Jung Typology Test™ http://www.humanmetrics.com/personality/type
This last link is for a popular variant of the MBTI which adds a fifth dimension called an extra scale A-T (Assertive – Turbulent). This does not particularly resonate with me, and I don’t use it. Perhaps because my percent score is almost exactly in the middle, 54& A 46% T.
Keirsey simplified these sixteen types into four groups, whose archetypes he equates with the classical four temperaments: NT (Rational), NF (Idealist), SP (Artisan), and SJ (Guardian) .
- NT (INTJ, ENTP, INTP, ENTJ): Called the Promethean or Rational temperament
- NF (INFJ, ENFP, INFP, ENFJ): Called the Apollonian or Idealist temperament
- SP (ISTP, ISFP, ESTP, ESFP): Called the Dionysian or Artisan temperament
- SJ (ISTJ, ISFJ, ESTJ, ESFJ): Called the Epimethean or Guardian temperament
Keirsey organized the groups asymmetrically, asserting Thinking–versus–Feeling as the most salient distinction among intuitives, but Perception–versus–Judging as the most salient distinction among Sensers. His methodology emphasizes the four temperaments, as he defines them, to generalize about different aptitudes and needs. Please Understand Me II (1998) is a sequel, whose methodology generalizes more so according to these four categories .
I remember quite clearly the first time I read through the complete set of 16 type descriptions, and was surprised to read a very positive description of my type, and that almost all the other type descriptions were very negative, to the extent that I felt sorry for other types having to read their descriptions. It was only later, probably as a result of interacting with other types in an MBTI training session, that I realized that my reaction was because I have quite strong (polarized) preferences for most of the four dimensions in the MBTI, and that others similarly would read their type as positive and others as less desirable.
Years later, I saw this play out in another MBTI workshop. My boss was a strong P (Perceiving) who ignored all deadlines in favour of getting a better product at the end, and was quite abusive to staff who aimed and planned to meet deadlines. At the workshop, he had a Eureka moment where he told the group that for the first time in his life he had realized that Js (Judgers) were not simply trying to avoid work, but valued meeting deadlines. Sadly that realization did not last long, and he was soon back to being quite intolerant of other types and their preferences for work styles.
Descriptions of the typical behaviours and preferences of these types typically ignore the complexity that there is a continuum along each of the four dimensions and are treated by many rather as if they were horoscope descriptions of you as an individual. Apart from ignoring the continuum and describing a type that has reasonably strong preferences on each of the four dimensions, many of the type profiles concentrate on positive statements about each type. At least positive in the eyes of that type, for whom the positives are already their preferred way of functioning.
There are type descriptions that discuss not only the strengths and positive preferences of each type, but also their weaknesses and limitations (see for example, B). I have come across a set of type descriptions which go a little further to discuss the more common pathologies and personality disorders for each type, though unfortunately I cannot recall where. Apart from the continuum of preference strength, and the positive and negative aspects of each preference dimension, I suspect many of the MBTI aficionados tend to forget that it is not a complete map of all aspects of variation of personality/temperament/functioning style across people. Apart from the various other “personality” scales that are preferred among clinical and academic psychologists (of which a little more later), there are other key domains or dimensions in which people vary. These include sex/gender (eg. masculine/feminine), intelligence (whether general intelligence or more specific domains of intelligence), and personality disorders (borderline personality disorder and the so-called dark triad of Machiavellianism, psychopathy and narcissism). The distributions of MBTI types differ somewhat between males and females, and my experience is that the presence of a personality disorder can substantially override the MBTI preferences.
Although type is viewed by some as putting people in a box and oversimplifying personality, I view it as a system to use as the beginning of understanding the functioning preferences of myself and others, and how this plays out in interactions and relationships. In doing so, it is important to keep in mind the complexities discussed above and not simply treat everyone as if they match one of the 16 “standardized” type descriptions.
Criticism of the MBTI
I was quite surprised recently to come across several articles in the scientific literature and on the internet which dismissed the MBTI as having low validity and reliability, much lower than other personality tests [3-6]. There seem to have been a rash of journalists trashing MBTI around 2013 onwards. For example, Todd Essig said  “The MBTI is pretty much nonsense, sciencey snake oil. As is well-established by research, it has no more reliability and validity than a good Tarot card reading.” Various academic psychologists who have commented online in Quora discussions, have stated that psychologists do not administer the MBTI, and it has fallen so far out of fashion that no one is even doing research on its psychometric validity anymore.
Adam Grant, one of the most vocal critics of Myers-Briggs, argues that the test is built on scientifically weak ground. Its results are not “reliable”, he says . The Myers-Briggs proclaims a reliability (calculated using coefficient alpha) of between .75-.85 on all of its scales (see Myers-Briggs testing manual). This means that around 50 per cent of subjects change at least one of their four types when they retake the test. And according to Grant, even the benign revelations that the test provides, such as the preferences of a married couple at a party, are baloney.
What to make of these criticisms. The criticism that the MBTI puts people in one of 16 boxes and reality is more complicated, I have already discussed above. The MBTI descriptions vary in quality depending on whose descriptions you read, but all should be read as describing a person with moderately strong preferences on all four dimensions, and real people will fall closer or further from these descriptions according to their strengths of preferences.
The second criticism that the test has low reliability and the type will change for 50% of people on retesting is completely outside my experience. I have discussed MBTI with relatives, friends and colleagues over 30 years, and done workshops with people who have had their type assessed previously, and in almost all cases their type has remained stable over time. I do have one close friend who was a T, but it was a weak prefence over F. He made a conscious decision to work on his personal growth and develop his F side, and over a period of a year claimed that his type changed to weak F. There is of course the question of whether his preference changed, or his stated preference as assessed from question responses changed because of his wish to be more F.
This points to one possible factor in “type change”. The assessment relies on people answering the questions honestly about their current preferences and its quite likely that some people may believe that another preference is more desirable or socially acceptable, and answer questions based on what they want their preference to be. Yixuan argued in a blog post  that most of the typical test questions are asking fairly directly about preference on a dimension and it is pretty clear to the user which dimension is involved and what each possible answer would mean. He proposes using computer programs (AI) to analyse text written by the person (say in a blog) and identify the type using objective measures that had been developed by machine learning on a body of text from persons with known types.
One website (https://personalitymax.com/) starts by saying that “The MBTI is an incredibly unreliable assessment tool. As far as Jungian personality types go, it’s much safer to determine one’s type by introspecting about their preferences on each dimension. However, most people try to assess their type using an online quiz and end up identifying as a type that does not represent their true cognitive model. This site claims that most people who take an online quiz end up with a result telling them they are an ‘intuitive’ type – as the tests tend to be biased toward ‘intuitive’ answers. As a result, a large range of people end up perpetuating false stereotypes about various intuitive personality types.
This argument does not seem borne out by data on the distribution of types in the general population and on web-based tests (see graph below). While N’s are over-represented in the web population compared to general population, there are still a majority of S’s in both the web and general populations. I would argue that the over-representation of intuitives (Ns) and introverts (Is) on the web compared to the general population reflects the personality types who are more likely to seek out personality tests on the web and hence is a selection effect, not a mistyping effect.
That said, mistyping is clearly more likely to occur for people whose preference is weak on a dimension, and careful readiing and reflection on descriptions of type preference may well result in a better attribution of that preference. The MMDI (Metasara) online test actually gives you the option to read rhe type description and to modify it to another close neighbour type. In my case, the I bias of the MBTI (if it actually exists) is not a problem because I really am a fairly strong I. Hence, I may have a stronger sense of the MBTI test’s reliability than is really the case. So I turn to all the people I know who have been typed reliably and it is stable and predictive. But I realize that most of them are also I and so have the same issue. Probably because S’s are never going to take an interest in MBTI and discuss it with me over the years. So it may be that the mistyping issue for tests is why the MBTI has a bad name in the psych literature, rather than that the types per se are not accurate.
The third major criticism of the MBTI is that the 16 type descriptions are nonsensical “horoscope” predictions. There are quite a few occasions when I have “typed” a close relative, friend or colleague who I know very well and by comparing their observed behaviours for each of the four dimensions arrived at a type which on checking in with them turns out to be correct. There are some people I have done this with, where there was a dimension I could not predict, and it turns out to be a dimension on which their preference is weak.
Face validity of the four MDTI dimensions of functioning preference
The most recent MBTI workshop I did included a group exercise which dramatically confirmed the validity of the type descriptions for me. I was in a group of about 30 people who had all completed a version of the MBTI test and been given their resulting four character type. For each dimension in turn, the group was asked to stand up and arrange themselves along a straight line according to the strength of their preference on that dimension (eg. Strong T at one end, strong F at the other). The line was then divided at the midpoint, and each of the two resulting groups (eg. T group and F group) were given an exercise to do as a group. The two groups then reported their results back to everyone with dramatic effect. I summarize the results of the four exercises. I found the T/F and J/P results particularly striking.
Each group was asked to describe the attributes of Es and Is. Both Es and Is agreed on some aspects of Es (noisy, shallow) but disagreed on others (each thought that the other was boring).
Each group was asked to describe a coke bottle. The Sensates described it as made of polypropylene, with various colours and dimensions, multilingual label, and has expiry date. The intuitives described it as unhealthy, good for a hot day, aesthetic bottle shape and emblematic of capitalism.
Each group was told they were a work team who had been offered funding to send a couple of members to a conference to present the results. They were asked to decide a process for choosing which team members should go. The Ts agreed fairly quickly that the two people who had contributed the most to the outcome in terms of intellectual and technical input, and understood the product best should go The Fs decided that the two admin support staff who had received limited recognition for their contribution should go. Their overriding concern was to preserve team harmony and ensure that no-one was unhappy about being overlooked.
Each group was to decide how they would organize a group vacation to spend some days camping and walking in the mountains. The Js worked out a timetable for making decisions on where to go, with an early meeting several months beforehand to decide on destination and itinerary, and to assign tasks to each member of the group to plan and book transport, to plan and acquire the necessary food provisions, to organize other group equipment such as tents and cooking gear, and so on. They would also meet nearer the date of the trip to confirm all arrangements and necessary tasks had been done and identify any remaining issues, such as bad weather contingencies. The perceivers agreed to meet a few days before the trip to have a drink and decide where they would go. They would then jump in cars and go.
According to Jeffrey Hayes, the chief executive of CPP, the company that now owns the original MBTI test, this kind of experience is at the heart of the test’s popularity. “The reason it endures is that people find its insights very valuable,” he says. “It helps them lead more productive and fulfilling lives.” I would add to that, that the MBTI is describing real observable behavioural differences that it is extremely helpful to understand and enable you to interact more effectively with people with different preferences, or at least to understand them better. As the exercises I described above show, these behavioural differences can be stark and easily observed. Measurement issues and misattribution aside, and I am very aware of the very large limitations of survey instruments of all kinds, the four dimensions of the MBTI seem to me to be important, observable, and very useful to understand and be aware of in other people. And it is important to keep in mind that all four dimensions are continuua, not everyone has strong preferences on every dimension, and that other factors such as gender, neuroticism, personality disorders, and motivations are also important.
Another popular personality typing instrument, the Enneagram [8, 9], puts people into 9 numbered categories in a circular diagram. While it bears some relation to the MBTI and can be mapped to it, its classification is based much more on motivations than functional preferences, and it has a schema shown in the arrows below where each type will progress to another or regress to another.
The “big five” personality test
Personality psychology as a field has thrown most of it’s weight (and hopes, dreams, etc.) behind a five-factor model of personality referred to as “The Big 5”. There are five traits which are represented as continua (rather than categories like the simplistic versions of Myers-Briggs): Openness to experience, Conscientiousness, Extroversion, Agreeableness, and Neuroticism (a handy mnemonic is OCEAN). Of these, only one trait is closely shared with the MBTI — extroversion. Myers-Briggs does not focus on “neuroticism” or, indeed, any similarly negative trait, which may point to one of the reasons why the criticisms lobbed at the test by modern science have yet to undermine its popularity. As Adam Grant says, “Going around telling people that they’re neurotic and disagreeable will not win you any friends.”
I found an online version of the OCEAN test and took it. Possibly I am just too used to thinking in terms of the Myers-Briggs factors, but I really struggled to make much of the results for any of the OCEAN factors apart from Extroversion (where my result matched by MBTI type). For the others, apart from being unclear to me what the factors meant, I also had little idea what my scores were telling me about myself. Whatever the limitations of the MBTI, particularly in regard to the test reliability which probably varies across versions of the test also, I think it remains a very useful tool as it’s a starting point and gives us a common language to think about these things. And its dimensions are all observable as functioning preferences in myself and others, and give me insight into how to best interact with others, or to optimise my functioning and environment.
The scientific concerns are fine up to a point, and I hope that further research clarifies and addresses them, but I want a basic framework that can be verified in my everyday and not-so-everyday experiences. For instance, I don’t simply accept spiral dynamics. I’ve looked at the world through this lense and it made sense of much of my experience. And hopefully science will further clarify and address the issues discussed above.
 David Keirsey and Marilyn Bates. Please understand me: Character and Temperament Types. Prometheus Nemesis Book Company 1984.
 David Keirsey. Please understand me II. Temperament, character, intelligence. Prometheus Nemesis Book Company 1998.
 David J. Pittenger. Cautionary comments regarding the Myers-Briggs Type Indicator. Consulting Psychology Journal: Practice and Research, Vol 57(3), June 2005, 210-221
 Adam Grant. Goodbye to MBTI, the Fad That Won’t Die. Psychology Today, Sep 18, 2013 https://www.psychologytoday.com/us/blog/give-and-take/201309/goodbye-mbti-the-fad-won-t-die
 Todd Essig, The Mysterious Popularity Of The Meaningless Myers-Briggs (MBTI), Forbes, Sep 29, 2014 https://www.forbes.com/sites/toddessig/2014/09/29/the-mysterious-popularity-of-the-meaningless-myers-briggs-mbti/
 Murad Ahmed. Is Myers-Briggs up to the job? Financial Times Magazine 11 Feb 2016. https://www.ft.com/content/8790ef0a-d040-11e5-831d-09f7778e7377
 Palmer, Helen (1991). The Enneagram: Understanding Yourself and Others in Your Life. HarperSanFrancisco.
 Riso, Don Richard; Hudson, Russ (2000). Understanding the Enneagram; the practical guide to personality types. Houghton Mifflin Company.