How Accurate Is the Myers-Briggs Personality Test?

There are two types of people in the world: those who believe in the Myers-Briggs personality test and those who don't.

Except that's not true. Grouping people into two, three or 16 categories, which is the aim of a lot of personality tests, has never quite worked. And even in the case of the Myers-Briggs Type Indicator (MBTI), which is simultaneously the most popular personality test in the world and the most frequently debunked, non-experts and psychologists alike take varying positions about the value of the tool.

About 1.5 million people take the test online each year, and more than 88% of Fortune 500 companies, as well as hundreds of universities, use it in hiring and training, according to The Myers Briggs Company, a California-based firm that administers the MBTI. Even fictional characters, from Disney princesses, to Harry Potter and Darth Vader have been assigned an MBTI type. [Which Personality Types Are Most Likely to Be Happy?]

Despite the popularity of the test, many psychologists criticize it — hardly a few months go by without a harsh take-down of the MBTI in the media, where a psychologist will say that the Myers-Brigg is unscientific, meaningless or bogus. But there are others who take a milder view of the test. "Many personality psychologists consider the MBTI to be a somewhat valid measure of some important personality characteristics but one that has some important limitations," said Michael Ashton, professor of psychology at Brock University in Ontario.

What is the MBTI?

The MBTI was invented in 1942 by Katharine Cook Briggs and her daughter, Isabel Briggs Myers. Cook, always a keen observer of people and their differences, was inspired by the work of psychologist Carl Jung and his theories; for example, the concepts of introversion and extroversion. The mother and daughter devoted their lives to developing the type indicator, hoping to help people understand their tendencies and choose appropriate jobs. The test uses 93 questions to assess the following traits:

• Introvert (I) versus Extrovert (E)
• Intuitive (N) versus Sensory (S)
• Thinking (T) versus Feeling (F)
• Judging (J) versus Perceiving (P)

Based on the combination of traits people fall into, the test ultimately assigns them one of the 16 labels, such as INTJ, ENFP, and so on.

Why do psychologists doubt it?

Psychologists' main problem with the MBTI is the science behind it, or lack thereof. In 1991, a National Academy of Sciences committee reviewed data from MBTI research and noted "the troublesome discrepancy between research results (a lack of proven worth) and popularity."

The MBTI was born of ideas proposed before psychology was an empirical science; those ideas were not tested before the tool became a commercial product. But modern psychologists demand that a personality test pass certain criteria to be trusted. "In social science, we use four standards: Are the categories reliable, valid, independent and comprehensive?" Adam Grant, University of Pennsylvania professor of psychology, wrote on LinkedIn. "For the MBTI, the evidence says not very, no, no, and not really."

Some research suggests the MBTI is unreliable because the same person can get different results when retaking the test. Other studies have questioned the validity of the MBTI, which is the ability of the test to accurately link the "types" to outcomes in the real world — for example, how well people classified as a certain type will perform in a given job. [Why Do People Ghost?]

The Myers-Briggs Company says the studies discrediting the MBTI are old, but their results are still being perpetuated in the media. Since those early criticisms, the company says it has done its own research to refine the test and assess its validity. "When you look at validity of the instrument [the MTBI], it is just as valid as any other personality assessment," Suresh Balasubramanian, the company's general manager, told USA Today.

Some of the test's limitations, however, are inherent in its conceptual design. One limitation is the MBTI's black-and-white categories: You are either an extrovert or introvert, a judger or a feeler. "This is a shortcoming, because people don't fall neatly into two categories on any personality dimension; instead, people have many different degrees of the dimension," Ashton told Live Science. And, in fact, most people are close to the average, and relatively few people are at either extreme. By placing people into tidy boxes, we are separating people who are in reality more similar to each other than they are different.

The MBTI may be missing even more nuances by assessing only four aspects of personality differences. "Several decades ago, personality researchers had determined that there were at least five major personality dimensions, and more recent evidence has shown that there are six," Ashton said. "One of those dimensions involves how honest and humble versus deceitful and conceited someone is, and the other dimension involves how patient and agreeable versus quick-tempered and argumentative someone is."

Not entirely useless

Some of the shortcomings of the MBTI stem from the complex, messy nature of human personality. Neat categories of MBTI make personality look clearer and more stable than it really is, according to David Pincus, a professor of psychology at Chapman University in California. Psychologists prefer other tools, namely the Big Five, which assesses personality based on where an individual lies on the spectrums of five traits: agreeableness; conscientiousness; extraversion; openness to experience; and neuroticism. The Big Five model has a better record of scientific validation than the MBTI, experts say.

Still, the MBTI is not entirely useless.

People are drawn to tests like MBTI out of a desire to understand themselves and others. "The four dimensions from which the MBTI types are derived are all useful ones for describing people's personalities," Ashton said. [Can You Learn Anything While You Sleep?]

And even when the MBTI's results don't quite match your intuition about yourself or are just wrong, they can still provide insight. Many people who've taken the MBTI have noticed this effect. As a former employee at Bridgewater Associates (a hedge fund almost as famous for having employees take personality tests as it is for its $120 billion in assets) wrote in Quartz, the MBTI labels never seemed to fully describe a person. Instead, the real value of the test seemed to be in the push "to reconcile the gaps between what the test results tell us, and what we know to be true about ourselves."

In this sense, the MBTI can serve as a starting point for self-exploration by giving people a tool and a language to reflect on themselves and others. The test is "a portal to an elaborate practice of talking and thinking about who you are," Merve Emre, an associate professor of English at Oxford University in the United Kingdom, wrote in "The Personality Brokers," a review of the MBTI's history.

Ultimately, it's not the MBTI label, but the power of introspection that drives the insights and sometimes fuels the motivation to take steps to change one's condition.

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Originally published on Live Science.