# In defense of Myers-Briggs

Jun 2020   (Updated Mar 2021)

The Myers-Briggs Personality Indicator (MBTI) gets a lot of scorn:

## In defense of the MBTI

YOU DON’T HAVE TO BINARIZE THE AXES

90% of the complaints about MBTI come down to: you can’t split people into two groups along these axes! Yeah, OK, then how about we don’t do that?

Of course someone can be borderline. Most people are borderline along at least one axis. Early versions of the MBTI actually gave an “x” for someone near the middle. Let’s bring this back! In fact, let’s go further.

Behold: Dynomight™ MBTI notation:

• Strong preference: Capital letter
• Weak preference: Lower-case letter
• Borderline: x

For example: eNxJ is:

• weakly extroverted (e)
• strongly intuitive (N)
• borderline thinking / feeling (x)
• strongly judging (J)

This gives five bins for each axis. You can still sort of say it out loud by making the strong preferences louder. This gives 5⁴=625 possible results. Of course, there aren’t 625 discrete types of people either. Our goal isn’t to split people into groups, it’s to give a convenient summary of how they answered a bunch of questions.

To underline this point, I even created a Myers-Briggs quiz you can take in 2 minutes that gives results in this form.

To claim it’s never useful to discretize denies human nature. You might as well claim we shouldn’t say “hot” or “cold” but must always give a number of degrees.

IF YOU DON’T LIKE BINARIZATION THEN DON’T

If you’d like a test that gives the scores as continuous attributes, may I recommend… any test? For example, here’s the results of me randomly clicking answers on two popular websites:

Not convinced? You can even check the “official” results that gullible people pay money for. They look like this:

THE MBTI MIGHT AS WELL BE CALLED THE “BIG FOUR”

And what happens if you don’t discretize the axes? If you take continuous measurements (like every Myers-Briggs test ever gives you) they correlate strongly with four of the five big five measurements.

The rows show the four MBTI axes, while the columns show the Big Five axes. This shows that:

• The MBTI E-I axis is strongly correlated with the Big Five extraversion axis. (duh)
• The MBTI S-N axis is strongly correlated with the Big Five openness axis.
• The MBTI T-F axis is moderately correlated with the Big Five agreeableness axis and weakly correlated with the conscientiousness axis.
• The MBTI J-P axis is moderately correlated with the conscientiousness axis and weakly correlated with the openness axis.

To interpret these numbers, note that 74/69 is what you get when the axis is exactly the same thing with exactly the same name. These correlations are strong.

But don’t blame all the journalists for not knowing about this. After all this groundbreaking research is hot off the presses having only been published in 1989. Other research supports the same basic conclusion.

What does this mean? If you believe the MBTI is meaningless, fine. But you must also therefore believe the Big Five is meaningless!

THE MBTI’S REPEATABILITY IS FINE

If someone is near the middle, a small change can land them on the other side. This is why 35-50% of people fall into a different one of the 16 buckets when they re-test. The most common score for all axes is near the middle. There are 4 different axes. If some small measurement noise puts you over the middle on any axis, then you fall into a different bucket.

Since we aren’t binarizing the axes, this is not something to worry about. Instead, we should just ask: How repeatable are the continuous measurements? For reference, here’s Cronbach’s alpha for the Big Five, measured for an Arabic version. Higher numbers indicate better repeatability.

Trait Men Women
Neuroticism .83 .74
Extroversion .82 .83
Openness .79 .85
Agreeableness .82 .81
Conscientiousness .90 .92

And here’s the results for Myers Briggs:

Trait Men Women
EI .82 .83
SN .83 .85
TF .82 .80
JP .87 .86

YOU CAN ADD AN AXIS IF YOU WANT

The Big Five measures neuroticism, while the MBTI does not. This is, no doubt, a very important trait. Some MBTI variants add extra axes. For example, one can introduce an axis that measures turbulence vs. assertiveness. This is a measure of neuroticism in all but name.

## Why go with the MBTI?

Everything above just says the MBTI isn’t much worse than the Big Five. So why not just use the Big Five? Well, you just try it.

THE MBTI IS COMFORTABLE TO TALK ABOUT

Say you’re on a first date. You discuss your favorite Italian films, the pets you had growing up. Then, you ask How agreeable are you? How does that go?

If that seems cherry-picked, let’s go through all the attributes:

• How extroverted are you? This is fine.
• How neurotic are you? Uncomfortable.
• How agreeable are you? Uncomfortable.
• How conscientious are you? Somewhat uncomfortable.
• How open are you to experience? This seems fine, but isn’t.

Only one of the five is OK. And — as you surely noticed— that same attribute exists in the MBTI.

Can I tell you a secret? The MBTI’s names for the S-N axes are sensing and intuition. These don’t make any sense. The Big Five openness to experience is much more descriptive. And yet, I claim, the MBTI names are often better because they are meaningless. Everyone claims to be open! But since no one has any idea what “sensing” is, they’ll happily admit to it. Deliberate or accidental, this subterfuge is extremely useful.

For similar reasons, the MBTI’s omission of neuroticism is sometimes good. The alternative to four axes is often zero, not five.

The advantage of the the MBTI is precisely that it makes everyone feel like a beautiful snowflake. The axes are chosen and named ingeniously so as to make them easy to reveal.

THE MBTI IS POSSIBLE TO TALK ABOUT

Binarization is the key criticism of the MBTI. Still, we must confront the fact that binarization is a huge driver of the MBTI’s success. How do we reconcile this?

Say you’re a weirdo who is happy to tell your date your Big Five. How do you actually say it out loud? In fact, I am such a weirdo, and I end up saying something like “My neuroticism is low, my conscientiousness is high, my extroversion is moderate, and… ummm, what are the other axes?”

A big part of what makes the MBTI easier to talk about is that it has names for both ends of the axes. With the MBTI, you have the option of a coarse summary by saying something like “ESFP”. It’s at least possible! Of course, more precise measurements are better, but having options is a positive thing.

I think that we could also sort of make this work with my suggested notation by modulating the sound of your voice. (If you get eNxJ, you say “I’m an e en ex jay”).

## Summary

You don’t have to discretize the MBTI axes. The MBTI measures similar stuff as the Big Five with similar repeatability, but it is more appealing and dramatically easier to talk about. Don’t feel guilty about using it.

In theory the Big Five could adopt the advantages of the MBTI by doing two thing. (Not that I’m advising this!) First, create names for the axes that sound more neutral, so that people are happy to discuss them. Second, create different names for different ends of the axes, so that an easy optional discretization is possible. But honestly, why bother? If you did that, you’d have basically invented the MBTI.