Friday, December 19, 2014

What Does Your Myers-Briggs Score Say About You?

On today's episode of Let's Ruin Something You Thought Was Fun and Interesting, we examine the Myers-Briggs Type Indicator, or MBTI. Doubtless you've seen these four-letter acronyms flying around, and perhaps you've even taken a version of the test to find out all about yourself. Is it really, useful, though? For anything? Well, yes and no. Mostly no.

The MBTI was developed by a mother-daughter team, Katherine Cook Briggs and Isabel Briggs Myers, over several decades in the early twentieth century. It was originally the brainchild of Katherine Briggs, who was inspired to build on and refine the "psychological types" theory of famous psychologist Carl Jung. The pair's tireless efforts culminated in the introduction of a formal version of the MBTI test in 1962.

The method behind the four-letter type indicators is largely an extension of Jung's theory of introversion vs. extroversion and how that distinction manifests itself in personality preferences. It splits an individual's personality into four dichotomies: Introvert-Extrovert, Sensing-Intuition, Thinking-Feeling, and Judging-Perceiving. The theory supposes that everyone displays a dominant preference in each dichotomy, indicated by one's corresponding four-letter score: ENTJ, ISFP, ESTP, et cetera.

The MBTI has enjoyed uninterrupted success and popularity for decades, mostly because it's a fun test to take, and people love being able to label themselves as something. (Buzzfeed is subsisting almost entirely on this idea.) We humans insist on forcing discontinuity onto our categorically continuous reality, so the idea that every individual can be classified as one of 16 personality types is fantastically appealing. Modern versions of the test even have a heroic-sounding label for each type, like "The Showman" (ESFP) and "The Confidant" (INFJ). (Click here to see which superhero you are!) One wonders how popular the test would be if it labeled people by their stereotypical negative character traits instead, like "The Insufferable Elitist" (INTJ) and "The Oblivious Materialist" (ESTP). Actually, has anybody done that? Let's do that.

Not so excited to add "ENTJ" to your dating profile anymore, are you?

As fun as the MBTI is, there are serious and numerous problems with it. The two women who developed it, for all their enthusiasm and tireless effort, were not psychologists. Neither of them had any formal training in psychology or in any science whatsoever, so the development of the test was patently unscientific. Even though the test has been administered for decades, many psychologists continually question the validity of the MBTI, and for good reasons.

First of all, the test relies on the honest input of the test-taker. Anyone not answering the questions honestly for whatever reason will obtain an "inaccurate" result. Secondly, there's no way to argue with anyone's result, because the test is unfalsifiable. It's impossible to demonstrate that someone isn't an ENFP, for example. Anyone who takes the test is free to agree or disagree with the result, and nobody could possibly argue.

Another reason that experts openly question the validity of the test is its alarmingly high rate of test-retest unreliability. People who take the test and then take it again several weeks later have a significant chance of getting a different score. This is because the test relies heavily on arbitrarily-defined dichotomies, pushing people to one side of the spectrum or another, when most of us are somewhere in the middle. Someone who displays an even mix of introversion and extroversion in different situations is likely to receive different results on retests. For example, two individuals who have nearly identical personalities could receive polar opposite MBTI scores if each one skews just slightly to the ETSJ (totally extroverted) or INFP (totally introverted) side of the line, indicating falsely that these people couldn't be more different.

This is the problem with a test predicated on dichotomies in general: there is no such thing as an introvert or an extrovert. Statistical models of all four indicators consistently demonstrate that the general population fits a bell curve between the two extremes, not a bi-modal (the opposite of a bell curve) distribution. Only a small percentage of people are mainly extroverted or mainly introverted; the majority of people fall in between somewhere, and the MBTI is blind to this reality. Nobody is an INTJ, or an ENFP, or an ISTP. These people do not exist. Every individual is a different mix of EI, SN, TF, JP, and nearly nobody skews heavily to one side of each of those.

There is also no significant data showing that these MBTI scores correlate with vocational performance. The official exam even openly states that the test only measures preferences, not aptitude, so even though one personality type might prefer a certain vocation, there is no guarantee of success or competence in practice. (This is probably why the official test also explicitly states that the MBTI should not be used to screen job applicants.) There is also no significant correlation between MBTI and industry: every vocational field has a more-or-less random sampling of MBTI types. Most actors are not ESTPs, for example, nor are most CEOs ENTJs.
So, what does your MBTI say about you? Well, certainly nothing that you didn't already know about yourself. The test really only needs to be four questions long:
  1. Are you more extroverted or introverted? (I/E)
  2. Do you primarily gather information via your senses or your intuition? (S/N)
  3. Do you make decisions more by thinking or feeling? (T/F)
  4. Which is more important to you, #2 above or #3? (P/J)
If you find some or all of these questions difficult to answer definitively, congratulations! You're a normal person who can't be easily classified by the MBTI. If you have a clear preference in each, then you can easily identify your "type," and most likely so can anybody who's known you for longer than 10 minutes.

The only thing that the Myers-Briggs Type Indicator result shows definitively is... that you've taken the Myers-Briggs Type Indicator test. Any conclusions drawn beyond that should be taken with a football stadium full of salt.

1 comment:

  1. Oy! I totally identify as a Smothering Idealist!

    Myers-Briggs is one of those tests that should be put in the same category as Cosmo's "Are you a good kisser?" type quizzes. As in might be fun to take in a slumber party to giggle about the results that are conveniently written with vagueness a kin of horoscopes and bible.

    Good analysis and much enjoyed your versions of the personality types.