Why the Myers-Briggs test is totally meaningless

The Myers-Briggs Type Indicator is probably the most widely used personality test in the world.

About 2 million people take it annually, at the behest of corporate HR departments, colleges, and even government agencies. The company that produces and markets the test makes around $20 million off it 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."

Analysis shows the test is totally ineffective at predicting people's success at various jobs

The test claims that based on 93 questions, it can group all the people of the world into 16 different discrete "types" — and in doing so, serve as "a powerful framework for building better relationships, driving positive change, harnessing innovation, and achieving excellence." Most of the faithful think of it primarily as a tool for telling you your proper career choice.

But the test was developed in the 1940s based on the totally untested theories of Carl Jung and is now thoroughly disregarded by the psychology community. Even Jung warned that his personality "types" were just rough tendencies he'd observed, rather than strict classifications. Several analyses have shown the test is totally ineffective at predicting people's success in various jobs, and that about half of the people who take it twice get different results each time.

Yet you've probably heard people telling you that they're an ENFJ (extroverted intuitive feeling judging), an INTP (introverted intuitive thinking perceiving), or another one of the 16 types drawn from Jung's work, and you may have even been given this test in a professional setting. Here's an explanation of why these labels are so meaningless — and why no organization in the 21st century should rely on the test for anything.

The Myers-Briggs rests on wholly unproven theories

Carl Jung in 1960. (Douglas Glass/Paul Popper/Popperfoto/Getty Images)

In 1921, Jung published the book Psychological Types. In it, he put forth a few different interesting, unsupported theories on how the human brain operates.

Among other things, he explained that humans roughly fall into two main types: perceivers and judgers. The former group could be further split into people who prefer sensing and others who prefer intuiting, while the latter could be split into thinkers and feelers, for a total of four types of people. All four types, additionally, could be divided based on attitudes into introverts and extroverts. These categories, though, were approximate: "Every individual is an exception to the rule," Jung wrote.

Even these rough categories, though, didn't come out of controlled experiments or data. "This was before psychology was an empirical science," says Grant, the Penn psychologist. "Jung literally made these up based on his own experiences." But Jung's influence on the early field was enormous, and this idea of "types" in particular caught on.

None of this came out of controlled experiments or data — it was all theoretical

Jung's principles were later adapted into a test by Katherine Briggs and her daughter Isabel Briggs Myers, a pair of Americans who had no formal training in psychology. To learn the techniques of test-making and statistical analysis, Briggs worked with Edward Hay, an HR manager for a Philadelphia bank.

They began testing their "Type Indicator" in 1942. It copied Jung's types but slightly altered the terminology, and modified it so that people were assigned one possibility or the other in all four categories, based on their answers to a series of two-choice questions.

Raise two (the number of possibilities in each category) to the fourth power (the number of categories) and you get 16: the different types of people there apparently are in the world. Myers and Briggs gave titles to each of these types, like the Executive, the Caregiver, the Scientist, and the Idealist.

The test has grown enormously in popularity over the years — especially since it was taken over by the company CPP in 1975 — but has changed little. It still assigns you a four-letter type to represent which result you got in each of the four categories:

The Myers-Briggs uses false, limited binaries

With most traits, humans fall on different points along a spectrum. If you ask people whether they prefer to think or feel, or whether they prefer to judge or perceive, the majority will tell you a little of both. Jung himself admitted as much, noting that the binaries were useful ways of thinking about people, but writing that "there is no such thing as a pure extravert or a pure introvert. Such a man would be in the lunatic asylum."

But the test is built entirely around the basis that people are all one or the other. It arrives at the conclusion by giving people questions such as "You tend to sympathize with other people" and offering them only two blunt answers: "yes" or "no."

"There is no such thing as a pure extravert or introvert," Jung wrote

It'd be one thing if there were good empirical reasons for these strange binary choices that don't seem to describe the reality we know. But they come from the disregarded theories of an early-20th-century thinker who believed in things like ESP and the collective unconscious.

Actual data tells psychologists that these traits do not have a bimodal distribution. Tracking a group of people's interactions with others, for instance, shows that as Jung noted, there aren't really pure extroverts and introverts, but mostly people who fall somewhere in between.

All four of the categories in the Myers-Briggs suffer from these kinds of problems, and psychologists say they aren't an effective way of distinguishing between different personality types. "Contemporary social scientists are rarely studying things like whether you make decisions based on feelings or rational calculus — because all of us use both of these," Grant says. "These categories all create dichotomies, but the characteristics on either end are either independent from each other, or sometimes even go hand in hand." Even data from the Myers-Briggs test itself shows that most people are somewhere in the middle for any one category, and just end up being pigeonholed into one or the other.

This is why some psychologists have shifted from talking about personality traits to personality states — and why it's extremely hard to find a real psychologist anywhere who uses the Myers-Briggs with patients.

There's also another related problem with these limited choices: look at the chart above, and you'll notice that words like "selfish," "lazy," or "mean" don't appear anywhere. No matter what type you're assigned, you get a flattering description of yourself as a "thinker," "performer," or "nurturer."

This isn't a test designed to accurately categorize people, but rather a test designed to make them feel happy after taking it. This is one of the reasons it's persisted for so many years in the corporate world after being disregarded by psychologists.

The Myers-Briggs provides inconsistent, inaccurate results

(Frederick Florin/AFP/Getty Images)

Theoretically, people might still get value out of the Myers-Briggs if it accurately indicated which end of a spectrum they were closest to for any given category.

But the problem with that idea is the fact that the test is notoriously inconsistent. Research has found that as many as 50 percent of people arrive at a different result the second time they take a test, even if it's just five weeks later.

As many as 50 percent of people arrive at a different result the second time they take the test

That's because the traits it aims to measure aren't the ones that are consistently different among people. Most of us vary in these traits over time — depending on our mood when we take the test, for instance, we may or may not think that we sympathize with people. But the test simply tells us whether we're "thinking" or "feeling" based on how we answered a handful of binary questions, with no room in between.

Another indicator that the Myers-Briggs is inaccurate is that several different analyses have shown it's not particularly effective at predicting people's success at different jobs.

If the test gives people such inaccurate results, why do so many still put stock in it? One reason is that the flattering, vague descriptions for many of the types have huge amounts of overlap — so many people could fit into several of them.

This is called the Forer effect, and is a technique long used by purveyors of astrology, fortune telling, and other sorts of pseudoscience to persuade people they have accurate information about them.

The Myers-Briggs is largely disregarded by psychologists

All this is why psychologists — the people who focus on understanding and analyzing human behavior — almost completely disregard the Myers-Briggs in contemporary research.

Search for any prominent psychology journal for analysis of personality tests, and you'll find mentions of several different systems that have been developed in the decades since the test was introduced, but not the Myers-Briggs itself. Apart from a few analyses finding it to be flawed, virtually no major psychology journals have published research on the test — almost all of it comes in dubious outlets like The Journal of Psychological Type, which were specifically created for this type of research.

Virtually no major psychology journals have published research on the test

CPP, the company that publishes the test, has three leading psychologists on their board, but none of them have used it whatsoever in their research. "It would be questioned by my academic colleagues," Carl Thoresen, a Stanford psychologist and CPP board member, admitted to the Washington Post in 2012.

Apart from the introversion/extroversion aspect of the Myers-Briggs, the newer, empirically driven tests focus on entirely different categories. The five-factor model measures people's openness, conscientiousness, extroversion, agreeableness, and neuroticism — factors that do differ widely among people, according to actual data collected. And there's some evidence that this scheme may have some predictive power in determining people's ability to be successful at various jobs and in other situations.

One thing it doesn't have: the marketing machine that surrounds the Myers-Briggs.

So what is the Myers-Briggs useful for?

The Myers-Briggs is useful for one thing: entertainment. There's absolutely nothing wrong with taking the test as a fun, interesting activity, like a BuzzFeed quiz.

But there is something wrong with CPP peddling the test as "reliable and valid, backed by ongoing global research and development investment." The company makes an estimated $20 million annually, with the Myers-Briggs as its flagship product. Among other things, it charges between $15 and $40 to each person who wants to take the test, and $1,700 to each person who wants to become a certified test administrator.

About 200 federal agencies reportedly waste money on this test

Why would someone pay this much to administer a flawed test? Because once you have that title, you can sell your services as a career coach to both people looking for work and the thousands of major companies — such as McKinsey & Co., General Motors, and a reported 89 of the Fortune 100 — that use the test to separate employees and potential hires into "types" and assign them appropriate training programs and responsibilities. Once certified, test administrators become cheerleaders of the Myers-Briggs, ensuring that use of the outdated instrument is continued.

If private companies want to throw their money away on the Myers-Briggs, that's their prerogative. But about 200 federal agencies reportedly waste money on the test too, including the State Department and the CIA. The military in particular relies heavily on the Myers-Briggs, and the EPA has given it to about a quarter of its 17,000 employees.

It's 2015. Thousands of professional psychologists have evaluated the century-old Myers-Briggs, found it to be inaccurate and arbitrary, and devised better systems for evaluating personality. Let's stop using this outdated test — which has about as much scientific validity as your astrological sign — and move on to something else.

Correction: This piece previously stated that the military uses the Myers-Briggs for promotions in particular, rather than using it as a general tool.