Is the MBTI Test Scientific?

The MBTI’s Psychometric and Philosophical Milieu

Recently, we discussed how the Myers-Briggs Type Indicator® (MBTI®) differs from models of personality like the Big Five. Among the most profound differences is predictivity, which helps make the Big Five more applicable to academic research and selection. The Myers-Briggs Type Indicator, which is not a predictive instrument, provides a different kind of information focused on an individual’s preferences rather than their ability.

Beyond predictivity and practical usefulness in their respective spheres, how do the underlying theories behind these two models differ? What are their respective relationships with the history and current state of science?

3 Reasons why you should take the actual MBTI assessment

What is a science?

The famous philosopher of science Karl Popper gave us what is now a fairly standard test of whether something is scientific or not: falsifiability. The context for Popper’s insight was his contact with Sigmund Freud, who seemed to always be able to find evidence for his theories retrospectively, and Albert Einstein, who made predictions that could be disproved if they didn’t pan out. In Popper’s mind, what Einstein was doing was science and what Freud was doing was not.

While Popper’s insight has been highly influential, a strict application of it confines the concept of science largely to the hard sciences — physics, chemistry, biology, and so on. The concept of falsifiability has less relevance in the social sciences, particularly their highly valuable qualitative (rather than quantitative) branches.

In practice then, deciding what is and what isn’t science is complex and is itself a cultural, linguistic and philosophical question. It’s a question complicated further by the popular concept that to be scientific is by definition to be true (and vice versa).

How is Myers-Briggs Personality Type Useful in Everyday Life

Type theories vs. trait theories

Without a doubt, the type theory at the center of the Myers-Briggs framework is within the realm of the social sciences and not the hard sciences. As well, the concept of personality type more generally appeals to the qualitative end of the soft science spectrum. In other words, it’s something that is more readily observed and described with language than measured and calculated with data and formulas.

In contrast to the more comprehensive and qualitative idea of types, traits are a way of quantifying facets of personality. This is why instruments like those based on the Big Five model can return a numerical value for each of the traits it measures.

Psychometrics vs. theories

While type theories are conceptually qualitative and trait theories are conceptually quantitative, the instruments that measure them always use quantitative methods (psychometrics) that can be critically examined through a quantitative lens.

While type theory itself comes from the qualitative work of Carl Jung’s analytic psychology, the Myers-Briggs Type Indicator is the quantitative psychometric instrument that, indeed, indicates an individual’s type.

The most important statistical criteria for judging a psychometric instrument are validity (does it measure what it’s supposed to measure?) and reliability (does it measure that thing accurately?). The Myers-Briggs Type Indicator has consistently been shown to quantitatively identify underlying qualitative types validly and reliably, and these measurements have been explored extensively in thousands of peer-reviewed articles as well as the instrument’s technical manual.

Can your Myers-Briggs (MBTI) type change?

Philosophy, psychometrics, science, or what?

Whether Carl Jung’s original ideas about psychological type are scientific or not is certainly up for debate. There’s no doubt that they stray into the realm of philosophy, including traditional and quite ancient ideas about personality. Whether they are of value or not in the context of the Myers-Briggs is a separate question.

It’s clear that the Myers-Briggs Type Indicator can reliably and validly indicate a person’s type preferences. It’s a quantitative tool that accurately measures a set of qualitative concepts rooted in early psychology and philosophy.

“Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve.”

— Karl Popper

Heeding Karl Popper’s warning above, the Myers-Briggs framework doesn’t claim to have a monopoly on nor tell the whole story of personality. Instead, it provides a language and theoretical framework that helps individuals better understand themselves, others, and how they prefer to work and interact.

As with actual languages, it doesn’t make much sense to assess its inherent truth or falsehood (is French or Japanese “true”?), but rather observe that it achieves its goal of helping people to understand and communicate.