#MyersBriggs#PersonalityTests is popular and that is about the only thing it has going for it. In reality it is no better than rolling die and assigning people a personality profile based on the die roll.
Carl Jung's ideas are at the base of the test. Unfortunately Jung's work has never been empirically tested. Hint when your base level construct is unsound you might have a train wreck on your hands.
Not Stable/Repeatable - with a reliable test I should be able to give the test once and a few weeks later give you the same test and get the same result. Myers Briggs not so much.
Predictive Value - a useful test should predict outcomes in the real world. MBTI has no predictive value.
Forced Questions - the test asks questions that force you have a binary answer, yet human personality is better measured on a continuum.
Poorly selected boundaries - 16 Personality types doesn't come close to covering all of humanity, so these 16 are arbitrarily selected buckets.
Median split to select the boundaries. People close the median might further away from the people they're classified with than the people just the other side of the median.
…
…Example I might score 55% Thinker and someone else 40%. I will be bucketed as Thinking and the other person as a Feeling. Yet we're closer together, than we're to the extremes of our buckets.
MBTI ignores Neuroticism - a trait that is an important predictor of career, health and romantic outcomes.
Why do people think the results of the MBTI tells themselves something meaningful about themselves or their team?
The descriptions are generally vague and all of them are flattering. This called the Barnum or Forer effect. A fortune teller, Astrologer etc makes a vague statement that could apply to many/most people. The listener is pleasantly surprised to hear things that apply to them. Result they start to see themselves reflected in the test.
Finally when these tests are used inside organizations to hire etc, they can weed out neurodivergent people.