The Failure Of DISC, MBTI, And Other Personality Tests

Why personality tests are no reliable tools for hiring, firing, and setting up teams.

Patrick Heller
5 min readDec 2, 2021

In many organizations, personality tests considering 16 or more traits, or 16 or more personality profiles, prevail. There is an entire personality assessment industry worth billions of dollars and no doubt you’ve come across at least some of them. But have you ever wondered whether they’re truly valid and reliable?

Two of the most famous tests are the Myers-Briggs Type Indicator, or MBTI, based on the personality types as proposed by Swiss psychiatrist Carl Jung (1875–1961), and the DISC assessment, based on the work of American psychologist William Moulton Marston (1893–1947), who also invented — with his wife Elizabeth — the polygraph, and who gave us the comic book character Wonder Woman. The latter test is most famous for the colors that are used to indicate a certain personality type. These colors have even become part of the lingo in many organizations. Who hasn’t heard colleagues utter words along the lines of, “Peter is really blue and just can’t get along with John, because he’s really green.” And therein lies one of the many dangers of these tests. People are stigmatized because of what comes out of such a test, taken at a particular time under particular circumstances.

Moreover, the science behind tests like these is feeble, to say the least. The theories of Freud and his pupil Jung have all but been debunked in later decades already. So, guess what you get with a test based on personality types, based on debunked theories? Pseudoscience is what you get, especially when it concerns its supposed predictive abilities. Myer-Briggs exhibits significant scientific psychometric deficiencies, including poor validity, poor reliability, measuring categories that are not independent, and not comprehensive. In other words, the test doesn’t measure what it purports to measure, it doesn’t have predictive power, it gives different results for the same person on different occasions, and it’s missing key elements, like measuring neuroticism.


If you look into the DISC assessment, things get even hairier. Psychologist Marston propounded his DISC Theory in his book “Emotions of Normal People”, in 1928. He described four quadrants along two axes, with activity versus passivity on the vertical axis, and a favorable versus an antagonistic environment on the horizontal axis. According to Marston, you then get the following options:

· Dominance produces activity in an antagonistic environment

· Inducement produces activity in a favorable environment

· Submission produces passivity in a favorable environment

· Compliance produces passivity in an antagonistic environment

Marston associated colors with the four terms. He linked the color blue to Dominance, red to Inducement, yellow to Submission, and green to Compliance.

In 1956, industrial psychologist Walter Clarke (1905–1978) constructed an assessment based on Marston’s DISC Theory. He created a checklist of adjectives on which he asked people to indicate descriptions that were accurate about themselves. In 1965, Clarke and others changed the test, so that instead of using a checklist, the test forced respondents to choose between two or more terms.

Meanwhile, Clarke also changed some more. He changed the I in DISC from Inducement to Influence, the S from Submission to Steadiness, and the C from Compliance to Conscientiousness. He also changed the colors. Dominance became red and Conscientiousness became blue, while Influence became yellow and Steadiness green.

In subsequent decades, several different companies have adopted the model and have adjusted it to suit their own interests — mostly financial — even though all of them still love to namedrop psychologist Marston as the source of their test. Some have adjusted the C to mean Compliant, and have kept it blue, while again others have switched things around completely, with a green D for Dominant, a red I for Inspiring, a blue S for Supportive, a yellow C for Cautious, a horizontal axis going from left to right from task to people, and a vertical axis going from bottom to top from reserved to outgoing.

Needless to say, the described chaos of meanings of letters, terms, and colors, combined with the poor validity, the poor viability, interdependence, and lack of comprehension also force the DISC assessments into the realm of pseudoscience.

Yet, personality tests like Myer-Briggs, DISC, PAPI, and others, are still very much in use in organizations today. HR departments depend on tests like these to hire new personnel. The question is, why would a twenty-first-century organization be spending their scarce time and money, even basing the hiring of new employees, in other words, basing their future, on pseudoscientific claptrap? The bittersweet and short of it is ignorance. Most HR departments don’t have well-trained, critical psychologists in their ranks who oppose this nonsense. As a consequence, people who see other organizations use these tests, tend to submit to the idea that if a multitude of organizations worldwide uses them, well, then they must be okay (the psychological phenomenon called conformity is strong). On top of that, if they read that it’s all based on the work of a well-known psychologist, then the authority bias kicks in, and there we go!

Moreover, some qualified psychologists do not oppose these sorts of tests and use them as a starting point for further conversation. Of course, something like the DISC assessment is so easy to apply and so easy to use in daily parlance that it’s hard to weed out. You can do an online DISC assessment in minutes and receive your true color description immediately. How rich is it to know your color and politically make use of that whenever it suits you? Why would you relinquish control if you’re as red as a Ferrari? It’s in your personality!

I once heard a comedian say it best when he said the world is full of dumb people, together with a small number of people who are just smart enough to make good use of that.

Yet another brain myth busted!

If you are interested in stories like these and more, you can buy Essential Psychology for Modern Organizations from Amazon and other bookstores: