Why Personality Tests are Useless

Director of the Personality and Self-Knowledge Lab at the University of California, Simine Vazire, told The Atlantic in 2017 that the only thing a personality test can tell you is what you already know. And that’s it folks; no mystery here, that is my thesis.

But let’s unpack this, shall we? Okay, first things first, let’s all agreed that the majority of people LOVE personality tests. According to Dr. Jennifer V. Fayard, the reason why we are so fond of personality tests is because “we want to learn about ourselves, feel that we belong, and understand others.” That seems reasonable.

The Problem:

#1 We’re gullible.

The number one reason to be weary of personality tests is our own susceptibility to the Barnum effect. The Barnum effect, as described by California State University, Fullerton, “refers to the gullibility of people when reading descriptions of themselves” assuming they are different and unique, even if it is a generic description given to many people. This phenomenon is especially true of big name personality tests like the Myers-Briggs Type Indicator and the Enneagram.

Both the Myers-Briggs and the Enneagram are widely recognized psychological tests created by a pair of psychologists and authors, respectively. The tests are promoted by household names like Ford, and are incredibility popular with HR departments. This recognition and prestige give its test takers a high confidence margin when they receive their results, especially if it aligns with the test taker’s own beliefs. What’s more interesting though, are the vast majority of people who accept the results even if they do not agree.

In her piece, Why Do We Like Personality Tests, Even the Bad Ones?, Dr. Fayard explains that one of the reasons why we accept inaccurate results is because we are biased in the way we process information about ourselves. This brings us back to the Barnum Effect, if we can relate to the results in some way, we are much more likely to accept them, even if they don’t exactly fit our perceptions of ourselves.

#2 We don’t know how to use personality tests.

There is an unfortunate disconnect between the intended utility of personality tests and how they are perceived. Dr. Vazire points out that personality tests are in fact meant as a tool for reflection; they do not offer any new insights on who you are, what your values are, how you would handle any given situation, etc, etc. Personality tests can not “see into your soul” they can only summarize your responses and group them together. In fact, Dr. Fayard argues that we are so trusting of our results, that we attach them to our identity and subconsciously fit them into our personality, whether they were truly accurate or not. Because we are so blindly accepting of our personality test results, it becomes hard to discern what came first: our personality traits or the personality test that outlined those traits.

#3 Personality Tests, by design, are BS

This is the killer. Most personality tests, including the Myers-Briggs Type Indicator and the Enneagram, are founded on complete horse manure (to keep it PG13). Let’s take a trip down memory lane, shall we? First, the Myers-Briggs was developed loosely on the work of Carl Jung, who pre-dates the scientific revolution in psychology, and thus did not use the scientific method to test his theories. In other words, Carl Jung based his theories on his own subjective experiences, as did the creators of the Myers-Briggs.

The other problematic aspect of the Myers-Briggs is it’s failed test-retest reliability. In psychology, and all sciences, it is important to get the same results over and over again to prove the reliability of any given instrument, drug, hypothesis, etc. The Myers-Briggs test has been shown to give different results to the same people who’ve taken it more than once, despite no major changes in their personality.

Moving right along, we have the Enneagram. This test was created by a former Jesuit with degrees in English and Philosophy along with his co-author, a scholar in East-Asian studies. It may very well be that these two co-authors are highly versed in the scientific method, and psychological research, but if they are, it is nowhere to be found as far as I can tell.

Regardless of this fact, the Enneagram has many of the same shortcomings as the Myers-Briggs, including the oversimplification of our personalities. Both the Myers-Briggs and the Enneagram use a “this or that” tactic to uncover our personalities, yet as it turns out, humans are more complex than that (who could have guested it?). The reason why these tests are developed in such a way may have something to do with our own desires to make things simple. In the words of Dr. Fayard,

When we interact with a person we know to be a member of a particular category or someone who seems like they belong to a category for which we have a schema, that schema is automatically activated and, like a script, guides our interactions with them. If we are familiar with the personality types in these systems, once a person tells us they are an ISFJ or a 7, we have a built-in template for how to understand them. 

In other words, we are using personality tests as a coping mechanism to help us compartmentalize complex individuals into nicely fitted boxes— and not to mention ourselves as well!

The Bottom Line

It seems that this argument comes up every few months between some of my die-hard personality tester friends and I. I’d like to point out that taking a silly personality test for fun is all good and well, but it becomes problematic when we start to depend on them to understand ourselves. When we accept any given explanation for being the way that we are, that explanation starts to manifest itself. The fact is, we do not do something or act in a certain why because we are “ISFJ,” it’s quite the opposite! There is a reason why personality tests are unpopular amongst most psychologist. The test cannot define your personality, it does not have the answers; you have the answers and you know yourself better than you think.


Your Favorite Personality Test Is Probably Bogus by Jennifer V. Fayard Ph.D

Why Do We Like Personality Tests, Even the Bad Ones? by Jennifer V. Fayard Ph.D

The Dark Side of That Personality Quiz You Just Took by Paul Bisceglio of The Atlantic

The Barnum Demonstration by California State University, Fullerton Dept of Psychology

The Wisdom of the Enneagram, about the author by Penguin Random House

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