The Myers-Briggs personality test classifies you as Introvert or Extrovert, Thinker or Feeler, and so on. It gives you a  four-letter type like “INTJ”. The catch is, Myers-Briggs is  kind-of bad.  If you’ve ever felt that Myers-Briggs seemed promising, but failed to deliver long-term benefits, here’s why.

Reason 1: Labeling ourselves is harmful

Myers-Briggs gives you a label.  That can limit our view of what we're capable of. If you are given a Myers-Briggs label which implies a weaker ability to interact with others, is that a permanent and accurate prediction of what you'll be able to do? No, certainly not! All the sources I quote on my site leave no doubt that the ability to deal effectively with others is a learned skill.  My own experience demonstrates the same.  I’ve started from zero and learned how to interact successfully with workmates.

(For more on the compelling argument against labelling yourself, read about the benefits of a Growth Mindset.)

I’m sure some fans of Myers-Briggs would point out that you’re not supposed to see your Myers-Briggs type as permanent. They can change over time. (In fact, as we’ll see below, they change rather too often.)  The problem is, most people who take the test see the result as permanent even if advised otherwise.  As soon as people start saying “I am an INTJ”, they are assuming their current strenghs and weaknesses will be permanent.  Science says otherwise:

Humans are open systems…

People retain the capacity to change at all ages.

(From the academic paper “Personality Change in Adulthood“, by Roberts and Mroczek)

Yes, we do have preferences. And different people do enjoy different levels of interaction and solitude. We should respect those preferences in ourselves and others, but we shouldn't mistake preferences for ability. You can develop skills far outside your Myers-Briggs "box". You don't have to do so, but the opportunity is there if you want to experiment with it.

Reason 2: Labeling others is harmful too

We’re taught as children that we shouldn’t stereotype other people.  Then we put on a suit, go to work, and some Myers-Briggs consultant tells us to start stereotyping again!  “Your colleague over there, she’s an ESTJ.  That guy, he’s an INFP.”

There are many reasons why we’re taught  to not stereotype.  One is that humans are prone to the “Fundamental Attribution Error”. That’s when we attribute our own behaviour to the unique circumstances of the moment at hand, but we attribute the behaviour of others to their traits or characteristics.  We might say, “I’m grumpy today because my kids are sick and I was awake half the night; but Bob’s grumpy because he’s a mean bastard.”  Surely we owe others the same decency we offer to ourselves, which is to recognise the existence of a real and complex human, operating in a real and complex world.  There’s a reason why its called the Fundamental Attribution Error.

Giving your colleagues Myers-Briggs labels encourages you to see their behaviour as stemming from their “fixed” traits, rather than from their circumstances of the moment.  Myers-Briggs is just the Fundamental Attribution Error dressed up in a fake moustache and glasses.

Reason 3: It’s not actionable

Say you know your own Myers-Briggs type, and that of your colleagues. What are you supposed to do about it?  How is that information supposed to help you deal with them more effectively?

Are you supposed to carry around in your head the whole matrix of 16 Myers-Briggs types, and for each one the knowledge of how you, given your type, should interact with it?  Even if you could do that successfully, wouldn’t your colleagues feel you were trying to manipulate them by tailoring your message to what they want to hear?

Wouldn’t it be much easier to learn one set of communication techniques which apply to all persons, of all personality “types”?  These universal techniques are the ones I advocate on my blog.  They are techniques which you use “in the moment”, responding to what this person is saying and doing, at this moment in time.  In doing so you respect the uniqueness of the other person and the uniqueness of their current circumstances.  Your communication works better, and besides, its easier than trying to carry around a mental matrix of 16 different ways to interact with 16 different “types”!

It’s worth noting that, of all the well-researched modern books I’ve read on dialogue skills, I don’t recall a single one ever saying anything about personality types.  They teach useful skills instead.

Reason 4: It distracts attention from the good stuff

There is so much good material on learnable practical skills.  It’s a crying shame that so much training on workplace interaction begins and ends with personality testing.

I saw first-hand evidence of this when I first started asking friends and colleagues about “people skills for geeks”.  Virtually everyone replied by telling me about a personality test they had been given, as if that was the first and last word on the matter.  I don’t recall any one of these people, most of whom had attended “professionally”-delivered courses, ever mentioning a single one of the learnable skills which I’ve since discovered from other sources.  It is those skills which will be the focus of this website in coming months, but for now, please allow me to put the boot into Myers-Briggs with one last vigorous kick….

Reason 5: It’s scientifically incorrect!

From a scientific point of view, Myers-Briggs just doesn’t add up.  To give just four examples:

• There is a scientifically-validated theory of personality, called the “Big 5“. It outlines 5 dimensions of personality that can be scientifically determined to exist. The catch is, only one of those dimensions (Introvert-Extrovert) exists in Myers-Briggs.  The other 3-dimensions of Myers-Briggs are basically mythical.  At best they are  conflations of the “real” Big 5 dimensions; and at worst they are just made up.
• Your type, as assessed by the Myers-Briggs test, can change significantly over short periods of time (e.g. 6 months).  If the results are that variable what, if anything, is it actually measuring?  And what value does the measurement have, if it can change so quickly?
• It promotes false dichotomies.  Myers-Briggs says you are either an Introvert or an Extrovert.  The facts, as measured by actual science, show this aspect of personality is more like a bell-curve with most people somewhere in the middle.  “Ambivert” is the correct term.
• Myers-Briggs would suggest that you are either good with ideas and data or good with people.  Science says those skills actually go hand-in hand.  The same part of the brain is used for planning (understanding work) and empathy (understanding people).  How many people, myself included, have mistakenly assumed these skills are mutually exclusive?

Professor Adam Grant wrote an excellent article about these, and other, problems with Myers-Briggs.  I heartily recommend it.    I also found a  portion of The Wisdom Paradox, by Elkhonon Goldberg, excellent on the point that the same part of the brain handles planning and empathy, and therefore those skills are correlated rather than mutually exclusive.

Conclusion

We have to stop putting ourselves in little 4-letter boxes.  It’s time to get on with learning skills instead of accepting restrictive — and scientifically bogus — labels.

I stand by the content of this post, and I would argue that science stands with me 😉   But I do apologise for any offence my wording may have caused.  If you happen to be someone who offers Myers-Briggs assessments, please allow me to respectfully make two comments.

• Firstly, if you’re in the business of helping people work together, it would be great if personality testing  made up only a minor part of your professional practice.  Something like 5% for example.  Why? Because there is just so much other good stuff to teach!  Your students will get more value from skills than labels.
• Secondly, perhaps personality testing is OK for the purpose of teaching students the lesson that, “Everyone, including you, has their own perferences and viewpoints”. But instead of Myers-Briggs, why not use a modern test with proven scientific validity?

Finally, if you happen to be a manager who purchases MBTI assessments for your staff… please stop.

[Updated 2019 to cover respecting preferences in ourseleves and others, without seeing perferences as limits.]