No, we haven’t been “duped” by the world’s most popular
personality assessment

By: Rich Thompson, PhD, Director of Research, CPP

The Myers-Briggs Type Indicator^® instrument (MBTI^®) remains the world’s most popular personality assessment for a reason – people find its insights useful. This is no accident. As Director of Research for CPP, the publisher of the MBTI assessment, I know firsthand the tremendous effort that goes into ensuring the MBTI’s validity and reliability. Despite the wide body of well-publicized research supporting its efficacy, certain critics continue to take shots at the instrument, which range from the misinformed to the purposely misleading.

The impulse on the part of some to mischaracterize the MBTI assessment was recently exemplified in a contributed article that ran in Fortune.com on May 15 titled “Have we all been duped by the Myers-Briggs test?” by Roman Krznaric. I’d like to take a moment to set the record straight, and respond directly to the criticisms levied by Mr. Krznaric:

“Despite its popularity, the personality test has been subject to sustained criticism by professional psychologists for over three decades.” While he’s certainly correct that the MBTI assessment has critics, it is well established that the Myers-Briggs instrument meets all requirements for psychological tests, and CPP freely publishes information substantiating its validity and reliability at www.psychometrics.com/docs/mbti_formm_supp.pdf. The Center for Applications of Psychological Type also publishes information on the reliability and validity of the Myers-Briggs at www.capt.org/mbti-assessment/reliability-validity.htm.

If it didn’t have a solid research-based foundation, it wouldn’t be used by the world’s top organizations, including IBM and Vancouver Olympic committee, as well as the majority of the Fortune 500. It has withstood more than 50 years of scientific scrutiny, and it has been cited and reviewed thousands of times.

It is true that the Myers-Briggs assessment isn’t popular with clinical psychologists, however, this is primarily due to the fact that it only assesses normal personalities and not pathology – therefore it is of somewhat limited use in clinical settings. It is, however, very popular with workplace and organizational psychologists who use it in more practical areas such as team building and conflict management.

Krznaric’s also claims that “…the MBTI mistakenly assumes that personality falls into mutually exclusive categories. You are either an extrovert or an introvert, but never a mix of the two…” Had the author done even a modest amount of homework, he would have known that this is misrepresentative of both the theory behind the instrument, and the measurement capabilities of the assessment itself.

The Myers-Briggs assessment merely says that we’re pre-disposed to behave in certain ways, not that our behavior is limited to one direction or the other. The theory behind it says that we use both preferences of any dimension, but we’re innately predisposed toward one. It’s just like a right-handed person using their left hand — it might not feel as natural, but they can certainly do it, and can become very good at it with practice. Right-handed people may exhibit varying degrees of skill using their left hand – that doesn’t render their designation as “right-handed” inaccurate or useless. It’s interesting that he falls back on a comparison to height distribution, which is completely inapplicable here, as height is a physical characteristic and not a behavioral preference.

Furthermore, the Myers-Briggs assessment actually does have a means for determining the degree to which a person identifies with a certain preference. It is called the “Preference Clarity Index (PCI),” which measures how clear an individual is about a particular preference — slight, moderate, clear, and very clear.

On a related note, Krznaric also references supposed “…low ‘test-retest reliability…’” In actuality, the test-retest correlations for the most recent version of the Myers-Briggs are in the range of .57 to .81, which is considered quite good for psychometric assessments. It’s worth pointing out that instances where people receive different results typically occur when they have a low PCI along a certain category. For example, if results initially show a slight preference for Extraversion, that individual might at a later time show a very slight preference for Introversion. It is rare for someone with a clear or very clear preference to show conflicting results from a subsequent assessment.

The author goes on to assert that “…there is no evidence to show a positive relation between MBTI type and success within an occupation … nor is there any data to suggest that specific types are more satisfied within specific occupations than are other types…” He then goes on to state: “…I apparently have the wrong personality type to be a writer… MBTI is not a magic pill that offers a secret path to a dream job.”

This is a little tricky because what he is saying is essentially true – the MBTI instrument does not predict performance or satisfaction within an occupation. However, it is misleading because it gives the impression that the assessment is intended to provide this kind of insight – it is emphatically not designed to predict success or satisfaction. To position this as some sort of shortcoming is as intellectually dishonest as saying that a compass is broken because it doesn’t tell you the temperature.

Some confusion stems from the fact that type influences people’s career choice – so certain types are more prevalent in various careers. While it doesn’t predict performance or satisfaction in a career, knowing your own personality type and the personality type most prevalent in the career you’re thinking of entering can be profoundly beneficial. For example, people find such insight valuable when it comes to communicating, presenting themselves, recognizing where they may encounter difficulties, and in general just getting along with the people they work with.

Finally, Krznaric rests his case on a familiar refrain: “…human personality does not neatly fall into 16 or any other definitive number of categories: we are far more complex creatures than psychometric tests can ever reveal.” First, l must point out that the Myers-Briggs assessment isn’t intended to describe every aspect of personality, and it doesn’t claim that individuals of the same type are alike. It’s really a straw man argument – neither the authors nor its publishers ever claimed that it classifies the entirety of human personality.

But let’s dig a little deeper into the assumptions underpinning this argument. According to this logic, human personality is so infinitely complex that any bit of insight into a person’s preferences for thinking, behaving, communicating, working and learning is useless – it offers no indication as to what makes them tick.

He’s free to believe that. However, countless managers, counselors, psychologists and others find that identifying certain common dimensions of personality is tremendously useful in team-building, conflict management, leadership development and numerous other applications.