Knowledge is knowing that a tomato is a fruit; wisdom is knowing not to put it in a fruit salad.

This post is written in response to Adam Grant’s LinkedIn article, Say Goodbye to MBTI, the Fad That Won’t DieAn interesting title, if it was indeed a fad then I’d agree – let it die – but people do actually get use out of it, so I’m not sure that a fad is the right way to describe the MBTI.

As a Psychologist who has always been critical of the MBTI, allow me to contribute to the discussion.  Your score is an indication of preference, not that you are more one than the other.  You don’t change preference, you only become more aware of what your true preferences are through your increased self-awareness.  The ‘test’ don’t tell you things that you don’t already know about yourself, they just highlight to you what others are likely to see or notice and provide you with guidance on things you might want to consider learning to do, behaviourally.  You can’t change your personality!

The test asks you to indicate your preference and acts as a mirror to how you see yourself.  It’s nothing like a polygraph because it can’t tell if you’re lying; it just mirrors back what you’ve said.  If you expect the MBTI to predict anything then you’ve been misinformed: it’s purpose is to support you in your personal development, to understand yourself and others, little else.

I take your point on the reliability and validity of the MBTI and, as an occupational psychologist, I too approached the tool with scepticism.  However, like all psychometrics, the setting up and administration of the instrument is critical to the effectiveness of the output.  Sadly, the world of online testing and automation has led to sloppy test administration, which is a significant factor in the reliability of a test

You’re not Schizophrenic – you’re just clearer than you used to be
Personality is not like a broken leg.  A preference is not so clear cut as bone fracture: if it was, then the human race would be very predictable, but I’m sure you’ll agree we’re not.  The clearer you are on your preferences, the more likely you are to get the same results when you re-take the test.  That’s it.

If you’re looking in the mirror then you’re looking backwards and not forwards
Preferring the colour green does not predict my performance in a job, in the same way that preferring to explore ideas from an intuitive rather than a sensing perspective will tell you nothing about my ability to work with excel spreadsheets.  Don’t confuse the MBTI with an ability test.  Equally, the four dichotomies of a Type Indicator says nothing about my motivations – so of course it won’t tell you anything about job performance.  If you think it will, then you’ve been misinformed.  Looking for a relationship between type and managerial effectiveness sounds like a good excuse to get funding for something that won’t show you anything.

Knowledge is knowing that a tomato is a fruit but wisdom is knowing not to put it in a fruit salad
The MBTI is only relevant for certain personal or team development activities.  Don’t use while operating heavy machinery, on medication or are feeling grumpy and highly critical.

  • Exhibit A: Scores for the different dichotomies (e.g. thinking and feeling) are in fact based on composite scores for both scales.  You do get a score for both sides and your preference is highlighted by the higher score.  Hence if you score equally on both, you score somewhere in the middle – indicating that you don’t have a preference for one approach over the other.
  • Exhibit B: The feeling type should not be confused with emotional intelligence (tendency to feel negative emotions, and the receptivity toward these emotions) nor traits – a very different theory of personality from ‘Type’.

A check-up versus invasive surgery
The MBTI could never be mistaken for a comprehensive assessment.  To think it is would be folly.

Falling in and out of love
I’m accredited to use many psychometrics, including the MBTI, but I rarely use it, mainly because the work I do doesn’t often warrant me using it.  However, I would use it for the right purposes.  Perhaps others use it because they’re not trained in anything else but, in my experience, businesses are more likely to talk to a consultancy for advice and support in using the right tool at the right time.

Understand what a psychometric is meant to do before you use it and don’t assume that one will work in all situations.  In the same way that you would go to your doctor or chemist to know what medication to take for your ailments, you should see expert advice from practitioners who know the different tools and how they should be used properly.


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