The Myers-Briggs Type Indicator (MBTI) is the most popular diagnostic self-test offered to identify personality type. The test is being used for selecting, replacing staff and validating candidates for promotions. Many careers have been made (or halted ) by the MBTI test, which is exclusively distributed by California-based CPP Inc.
During my university education, I learned about MBTI and fantasized about being able to accurately determine a personality within 45 minutes of testing 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 a required entrance level for a management training. 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 focusing on a certain type upfront. The testing method is not scientifically proven and is very commercially driven.
You should never participate in an MBTI test, unless you have determined the exact outcome you want to achieve.
What is the allure of MBTI?
MBTI is popular because it is simple to explain, easy to execute and takes limited time. MBTI offers 45 minutes to “accurately” determine someone’s personality. The test-taker is categorized in 1 of the 16 different personality types; easy to understand and easy explain.
The test results are delivered in an elaborate document containing a very recognizable description of your personality type. So most people are very pleased with the results. Over the past 2 decades, MBTI has become increasingly popular due to aggressive marketing by the MBTI-trust and their trainers.
Remember: MBTI is a type indicator. It is not a definitive verdict on someone’s personality. The test is too limited to give an idea about your overall personality (this usually takes months of testing). Unfortunately, the test is often used as a final and unchangeable description of someone’s personality.
What are the Arguments against MBTI?
1. The scientific grounds for the MBTI test are missing
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 until 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 has not been subjected to any control study. So he just made these things up by himself 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 whole basis for 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 to accomplish a significant different personality.
This means that a job candidate selected or validated based on his MBTI test results might be wrong in 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 subject you can only place yourself at the end of these spectrums; 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-takers mood, situation, priorities and other variables at the moment of the test. Only 30% of the people taking the test fit in 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 trades, people tend to look everywhere for confirmation of themselves and their personality types. So the natural reaction on the test results is to emphasize the things that conform with the test-taker’s personality and to dim down 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 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 (amongst others). A percentage of the money you pay for your MBTI test goes to CPP. A study by David J. Pittenger shows 2 million copies of the MBTI test are being sold annually. This roughly calculates to a market with an annual turnover of about 500 million dollar 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 usage 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 of a fortune cookie, the message has always 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.
