If I had a dollar for every client who comes to me for career counseling or life coaching who starts the session by saying “I’m an…(ENFJ; INTP, etc.) I’d be able to take a nice trip to Florida and escape the bitter cold we’re currently experiencing here in DC.

Barry Ritholtz, columnist and wealth management guru, wrote the following critique of the Myers-Briggs test this past July in Bloomberg View:

“An estimated 2 million people take it annually, at the behest of corporate HR departments, colleges, and even government agencies. The company that makes and markets the test makes somewhere around $20 million each year.

The only problem? The test is completely meaningless.

“There’s just no evidence behind it,” says Adam Grant, an organizational psychologist at the University of Pennsylvania who’s written about the shortcomings of the Myers-Briggs previously. “The characteristics measured by the test have almost no predictive power on how happy you’ll be in a situation, how you’ll perform at your job, or how happy you’ll be in your marriage.”

Aside from the fact that Myers-Briggs has little predictive value as to likely success on a particular career path, or in any given relationship, the test can be harmful by focusing the test subject’s attention on a certain set of personality characteristics to the exclusion of others*. Those who ascribe to astrology are victims of a similar phenomenon – just this week I had 2 clients tell me that they are Cancers and hence homebodies, reluctant to open up to others, irritable (crabby), etc. While it may be comforting to be able to boil down the complexity of one’s personality into just a few descriptors, it’s likely to distort one’s view of oneself and thus inaccurately point to certain paths forward and eliminate what might be promising options.

Harvard law professor Cass Sunstein, a prolific author on behavioral economics (the effects of psychological, social, cognitive, and emotional factors on the economic decisions of individuals and institutions) authored an article last month on Linkedin critiquing Myers-Briggs. In part it reads:

“Let’s look at the general disadvantages of using personality assessments to predict behavior. Many people quite confidently rely on impressions of personality to explain the actions of their friends and colleagues. Their confidence is often misplaced.

The problem is that we exaggerate how consistent people are across both situations and time. If someone is lazy around the house, we might conclude that he is also likely to be lazy at work or in the gym. If someone was easily distracted in class, he will also be easily distracted at work. But in many cases, this kind of cross-situational behavioral consistency does not exist. Most of us are a lot less consistent in how we behave in different situations than we think we are. This goes in spades for our beliefs about the consistency of other people. Relying on these mostly false beliefs about behavioral consistency and hence predictability, we are overconfident about how accurately we understand and can predict others.

If even weakly valid traits, like extroversion and conscientiousness, have low predictive value, an unscientific trait categorization like the Myers-Briggs score is going to be totally useless for purposes of prediction. 

Consider, for example, this question from the Myers-Briggs test: “Would you rather work under a boss (a) who is good-natured, but often inconsistent or (b) who is sharp-tongued, but always logical?” Your answer to this question is aimed to assign you to a “feeling” or a “thinking” category. Or consider this question: “Is it true (a) that facts ‘speak for themselves’ or (b) that facts ‘illustrate principles’?” Your answer indicates whether you belong in the “perception” or “judging” category. Or this: “Are you the kind of person (a) who is external and communicative and likes to express yourself or (b) who is internal and reticent and keeps to yourself?” Your answer types you as extroverted or introverted. The sixteen Myers-Briggs types are defined by four dimensions: extroversion-introversion, sensing-intuition, thinking-feeling, and judging-perception.

By some reports, almost 90 percent of the major US companies use the Myers-Briggs test for employee selection, placement, or counseling. But careful studies show that the test does not predict behavior of any kind with much validity. One problem is that the test has what statisticians call low test-retest reliability. If you retake the test after a one-month gap, there’s a 50 percent chance that you will fall into a different personality category from your original category.”

One last, personal observation on Myers-Briggs: I have yet to encounter a client who has told me that their Myers-Briggs test results had great value in helping them determine a career path. That’s why it’s so important to engage with an individually tailored career assessment process (like the one I offer).

* See my previous post on the subject of noticing exceptions to behavior patterns.