Neither Isabel Briggs Myers nor Katherine Briggs had any formal psychological training.

Even renowned psychological theorist Carl Jung, whose writing formed the initial inspiration for the Myers-Briggs test, admitted that terms such as “introvert” and “extrovert” were false dichotomies and entirely too limited to either adequately describe or predict human behavior.

Up to half of the people who take the test a second time end up with a different personality classification, even if they take it within five weeks of the first test.

According Annie Murphy Paul’s The Cult of Personality Testing, “as many as three-quarters of test takers achieve a different personality type when tested again…and the sixteen distinctive types described by the Myers-Briggs have no scientific basis whatsoever.”

Multiple studies have clearly demonstrated that the MBTI is incapable of accurately predicting job performance.

The test is used by most Fortune 500 corporations, but it is not typically used by professional psychologists.

Stanford University psychology professor Carl Thoreson, who is on the board of the company that issues the MBTI, has never mentioned the test in the over 150 academic papers he’s published. “I didn’t use it in any of my research,” Thoreson says, “in part because it would be questioned by my academic colleagues.”

The National Academy of Arts and Sciences conducted a study that concluded that the S-N and T-F scales had little to no validity.

There is absolutely no scientific basis for the test’s terminology, which has been criticized as “vague and general.”

As with all personality tests, it’s easy to fake one’s responses or describe oneself in ways that most others may not perceive you.

There is no way to validate it scientifically.

The Army Research Institute has advised that the MBTI should not be used in career counseling and has warned that “the types may simply be an example of stereotypes.”

According to a study in Review of Educational Research, “A review of the available literature suggests that there is insufficient evidence to support the tenets of and claims about the utility of the test.”