Can you trust the MBTI assessment?
John Hackston, Head of Thought Leadership at The Myers-Briggs Company
The Myers-Briggs instrument is the world’s most popular personality assessment largely because people find it accurate and useful in their lives. By helping people understand their own tendencies and inclinations, it allows individuals and organizations to optimize their talents and abilities. Its value in conflict resolution, leadership development, team building, and numerous other areas has been demonstrated through case studies, and it is used by the majority of the Fortune 100.
To be sure, not everyone likes the MBTI, and in fact, a few critics have essentially created something of a cottage industry around bashing it. These articles and videos follow a similar pattern of rehashing a few criticisms in a circular firing squad type atmosphere of critics citing each other as experts on how bad the MBTI is.
When you peel back the onion, however, you find that these criticisms are at best poorly thought through, and at worst are outright misleading. Let’s look at some of the more common refrains coming from MBTI critics.
It Is Based on Carl Jung’s Ideas
If it seems a little odd that people have a problem with the fact that the MBTI is based on theories of one of the major figures of psychology, you’re probably not alone. In Psychology Today Dr. Aqualas Gordon, a professor of psychology at Central Missouri University, discussed at length the benefit of having the instrument built on a strong theoretical foundation, which is exactly what Jung provides. Interestingly, the Myers-Briggs is fairly unique in this area. Other highly respected models, such as those based on the Big Five model, lack such theoretical underpinnings.
It Shouldn’t be Used to Predict Job Performance
Critics often point out that the MBTI is not designed to predict job performance. Interestingly, both The Myers-Briggs Company and The Myers and Briggs Foundation have long taken the stance that the MBTI assessment suggests predisposition, but not predetermination. Rather than pigeonholing, it empowers individuals to further shape their futures through an understanding of their own preferences and those of the people around them.
This makes the criticism that the MBTI is not predictive quite puzzling. A company that produces a hammer wouldn’t claim that it was intended for tightening screws. Likewise, it would make no sense for a hardware reviewer to claim that the hammer was useless because it didn’t tighten screws.
So why make this criticism? At the root of it is the idea that only instruments that predict certain outcomes, like job performance, have value. However, this view is limited and narrow-minded. The MBTI provides increased understanding and self-awareness that helps individuals to make better choices in how they interact with others, which lays the groundwork for improving their communication, conflict handling, decision making, and other aspects of work and life. And this is largely how the instrument is used among the Fortune 100, as well as top universities and government agencies.
The MBTI does in fact relate to numerous real-world outcomes, and thus has been used in many peer-reviewed studies. It doesn’t predict job performance, because that’s not what it was designed for. But it does what it’s intended to do--if it didn’t, they’d quit using it.
Does Human Personality Fall Along Continua, Or Into Discrete Categories?
A common refrain is that human personality can only be correctly understood if it is measured on a continuum, and that type categories are simply too limiting. While that certainly may ring true, in order to understand why it’s really an irrelevant criticism of the MBTI we have to go back to its theoretical underpinnings.
The Myers-Briggs instrument was constructed to reflect Jung’s theory of psychological types, assessing preferences for the opposite ways of using our minds that he described in his book, Psychological Types (1921). According to type theory, although an individual may engage in behaviors characterized by both poles within a preference pair, it is assumed that he or she naturally prefers one over the other. The Myers-Briggs assessment’s forced choice format is the most appropriate application of this theory, which holds that preferences are not skills or abilities, but rather dispositions to “automatically” respond in certain ways.
The theory states that every individual uses both poles of a dichotomy – for example, both Introversion and Extraversion. However, people are typically more comfortable with one preference and feel more natural and competent using it.
In this way, personality preferences have been compared to preferences for right-handedness or left-handedness. While in reality these probably also exist along a continuum, for practical purposes they are more easily understood as categories. Saying “I have a 60 percent preference for my right hand” might have some clinical application, but it’s not of much practical value in the real world.
The MBTI Has Poor Reliability
This claim is so patently false that it probably ought to call into question the motives of those who continue to peddle the argument. The publisher of the MBTI instrument has taken great lengths to make publicly available all of the data behind the instrument, and anyone can easily download and read it at https://www.themyersbriggs.com/MBTIvalidity. There’s not enough room in a single article to recount all of this, but here are some of the highlights:
- The Myers-Briggs MBTI Global Manual 4th Edition reports test-retest correlations up to 15 weeks for the most recent version of the Myers-Briggs instrument averaging .87 for the four scales, indicating good reliability for each preference over long periods of time. The general standard for a scale on any psychometric assessment is to have a reliability of .70 or above.
- Reliability across five employment statuses – employed full-time, employed part-time, full-time student, retired, and not working for income – range from .86 to .92, indicating that the Myers-Briggs instrument is reliable across a variety of employment situations.
- The reliabilities across ethnicity range from .80 to .92, and are similar across the nine ethnic groups, suggesting that the Myers-Briggs Form M assessment is reliable across a range of ethnic groups.
- The most recent data on the Global MBTI assessment shows an average alpha coefficient (measuring internal consistency reliability) of .89, well within the bounds for a psychometric assessment. Comparatively, the NEO Five-Factor Inventory scores .89 and DiSC scores .79.
The bottom line is that MBTI is backed by pretty impressive science. It has withstood more than fifty years of scientific scrutiny, and a simple search on the Center for Applications of Psychological Type’s MBTI Bibliography Search reveals nearly 11,000 citations of the MBTI assessment. Isabel Briggs Myers worked with Educational Testing Service in Princeton, NJ, a major test publisher, in developing the instrument, and twenty years of research preceded its initial 1962 publication. It conforms to all requirements for educational and psychological tests, and four technical manuals and supplements have been published—1962, 1985, 1998 and 2009, providing a wealth of research-based evidence on its reliability and validity.
The MBTI Doesn’t Measure Neuroticism
Finally, some have asserted that the MBTI instrument lacks value because it doesn’t measure ‘neuroticism’. I’m not sure whether to be amused or disturbed by that particular critique, but here is why I think it doesn’t hold water.
The MBTI’s value-neutral approach to personality type, in which preferences are regarded as neither good nor bad in and of themselves, is undoubtedly one of its aspects that makes it a useful tool for training. The MBTI tool gets people talking to each other about their type, and in doing so lays a foundation for better understanding of how individuals prefer to work and communicate.
Interestingly, a 1989 paper by McCrae and Costa, two leading Big 5 researchers, showed that the four dimensions of the MBTI correlated significantly with four of the Big Five dimensions. In fact, the only dimension that doesn’t correlate is the one that the MBTI doesn’t measure — neuroticism. And there’s a good reason for that. Take a step back and think about what would happen if the MBTI did measure “neuroticism”. It would quickly become a conversation closer. While such a measure may be needed in clinical settings, how many of us would ever discuss our own level of neuroticism with co-workers, or even with a career coach?
In the end, the MBTI is a popular instrument because it does what it was designed to do--provide practical, shareable and actionable insight into how we as individuals tend to think and behave. So why the assault? Perhaps Dr. John Johnson of Pennsylvania State University said it best: “I sometimes wonder if academics are not a little jealous of the commercial success of the MBTI and therefore look for ways to shoot it down.”