Why the Myers-Briggs Test (MBTI) Is Misleading, Harmful, and Poorly Suited for Workplace Decisions

The Myers-Briggs Type Indicator (MBTI) is one of the best-known personality tests in the world. It is widely used in corporate training, team-building sessions, and career development programs. In some cases, it has even been used to influence hiring, promotion, and leadership decisions.

During my university education, I learned about MBTI. I fantasized about being able to determine a personality within 45 minutes of testing accurately and projecting someone’s career path based on these test results. I have also researched a lot of the studies critical to MBTI and found the discussion about the validity of MBTI very interesting. Over the past few years, I have taken this test a couple of times (obligatorily and voluntarily). Mainly to satisfy my interest in this field and as an entry requirement for a management training program. Based on studies and personal experience, it is my opinion that MBTI is an inadequate tool for determining career path and/or promotion in the workplace. The results of the test are questionable and can be“influenced by trying to obtain a certain type in advance. The testing method lacks strong scientific support and is very commercially driven.

At first glance, the appeal is obvious. The test is simple, fast, and easy to understand. In less than an hour, it promises to sort people into one of sixteen personality types and offer insights into how they think, work, and relate to others. That promise is exactly why MBTI remains so popular. Unfortunately, popularity is not the same as validity.

Based on both the criticism surrounding the model and the way it is often used in practice, MBTI is a poor tool for making meaningful decisions about people’s careers, capabilities, or long-term potential. Its scientific foundations are weak, its results are inconsistent, and its categories are too rigid to capture the complexity of real personality.

Why MBTI is so appealing

MBTI is attractive because it offers clarity. It reduces something as complex as personality to a neat and memorable four-letter code. That makes it easy to explain, easy to market, and easy for people to remember.

It is also flattering. The descriptions are often written in a positive, affirming tone, which makes them feel insightful and personal. Many people read their result and immediately recognize parts of themselves in it. That experience can feel convincing, even when the description is broad enough to apply to many different people.

Over time, that combination of simplicity, confidence, and personal recognition has helped MBTI gain enormous popularity.

The main problems with MBTI

1. Its scientific basis is weak

In 1917, Katharine Cook Briggs began research into personalities to determine her future son-in-law’s personality. Soon she was joined by Isabel Briggs Myers, who added the different personality types based on the then recent work of Carl Jung. Neither Myers nor Briggs were formally educated in psychology and lacked scientific credentials in the field of psychometric testing. The work attracted the attention of Henry Chauncey, head of the Educational Testing Service. They developed their work to a commercial test in 1975 then sold the test and the manual to Consulting Psychologists Press (CPP). MBTI is based on eight hypothetical assumptions, and to this day, there has been no scientific proof to support the claims of the method. Carl Jung admitted the basis of his research was anecdotal and had not been subjected to any controlled study. So these ideas were largely speculative and not empirically validated and added some stories from his friends. 

Furthermore, MBTI has no lie scale, nor any measures designed to tap into respondents’ inclination to make socially acceptable responses or steer towards a desired outcome. This makes the entire basis of this test very questionable.

2. The MBTI test results are not repeatable and no indicator for success

When you want to be sure test results are accurate, you need to get the same result in a second test. Several studies, however, show that even when the test-retest interval is short (e.g., 5 weeks), as many as 50 percent of the people will be classified into a different type.” This is to say that the test fails to meet standards of ‘test-retest’ reliability.” (“Measuring the MBTI…And Coming Up Short”, Journal of Career Planning and Employment, 1993. 54: p. 48-53.)

You can argue the personality of the test subject is changed during these 5 weeks, however the time between these 2 tests is too short for someone’s personality to change significantly.

This means that a job candidate selected or validated based on their MBTI test results might be wrong 50% of the time, assuming one of the 2 test results is actually accurate.

And when we take a look at the results and the best-fitting jobs for this personality type we see no significant indication that the MBTI personality is a good predictor of someone’s success in a specific role. “..there is no evidence to show a positive relation between MBTI type and success within an occupation.” (Ibid., 1993)

3. The black-and-white MBTI scales force binary behavior

The MBTI doctrine forces a black-and-white choice. As a test taker, you can only place yourself at one end of these scales: E-I (“extravert-intravert”), “N-S” (intuitive-sensing), “T-F” (thinking-feeling), “P-J” (perceiving-judging). The model offers no spectrum on these scales for further situational nuance. The results are very subjective to the test-taker’s mood, situation, priorities and other variables at the moment of the test. Only 30% of the people taking the test fit into one of these extreme categories; the rest is somewhere along the scale. This means the categories are too rigid to describe a nuanced personality and ignore about 70% of the population. 

4. The MBTI test results are a Self-fulfilling prophecy

The results are written down in a series of good qualities and qualities you find difficult to handle. The real magic starts here. Since the positive characteristics are written in such a way that they are pleasant to read, and the negative qualities are written as inferior traits, people tend to look everywhere for confirmation of themselves and their personality types. So the natural reaction to the test results is to emphasize the things that conform with the test-taker’s personality and to downplay the not-so-fitting characteristics. Compare this with a horoscope or a fortune cookie; there is always a bit of truth in them so you get the feeling it is specifically written for you. Take a look at the description below that is from an ISTJ profile:

Serious, quiet, earn success by concentration and thoroughness. Practical, orderly, matter-of-fact, logical, realistic and dependable. See to it that everything is well organized. Take responsibility. Make up their own minds as to what should be accomplished and work toward it steadily, regardless of protests or distractions.

When reading this description a large group of people find it an accurate depiction of themselves. This is called the Forer Effect. 

5. There is a lot of money to be made with MBTI

The test only takes 45 minutes and can be purchased by certified MBTI organizations. Most of the time it is an online test program. The MBTI test is owned by the MBTI Foundation and executed by Consulting Psychologists Press (CPP), a privately owned company with no annual report available online. At the MBTI Foundation, you can certify yourself as an official MBTI testing facilitator (among others). A percentage of the money you pay for your MBTI test goes to CPP. A study by David J. Pittenger shows that two million copies of the MBTI test are being sold annually. This roughly calculates to a market with an annual turnover of about 500 million dollars in testing fees alone. This explains the extensive investment in marketing and research projects to generate pseudo-scientific proof for this method. There is a lot of money to be made from MBTI testing and from the additional training and coaching programs. MBTI is big business.

Conclusion: What can we do with MBTI?

The idea of using MBTI and the 16 categories for career planning is only useful as examples of stereotypes. The use of MBTI for career planning only reduces the attention to personal characteristics, qualities, and potential of each individual. And the results of a test become a self-fulfilling prophecy. If you tell people that they are “innovative thinkers and good problem solvers, and good at understanding and motivating people, but may have trouble following through on details of a project,” they will believe that the statement is an accurate description of themselves and act accordingly. And just like a horoscope or a fortune cookie, the message always has some truth in it, and we humans are always looking for confirmation.

So at best MBTI can be classified as a good list of stereotypes presented to you as a very complicated fortune cookie.

Further Reading:

https://eu.themyersbriggs.com/en/Knowledge-centre/Blog/mbti-facts-and-common-criticisms

https://www.academia.edu/download/37116706/PSYCH_43285.pdf

http://www.celebritytypes.com/blog/2014/02/mbti-for-skeptics/

Note: Myers-Briggs Type Indicator and MBTI are trademarks of the MBTI Trust, Inc.