I am putting up below the opening blast of a history of the MBPT. It makes some useful points. The curious thing about the MBPT is that it has intuitive appeal to a lot of people and many take its categorizations semi-seriously as applicable to themselvres.
That is rather a pity as the test is a psychometric disaster area. It is not internally consistent and often fails to give the same answer twice when it is administered on more than one occasion. It psychometrician's terms it lacks both validity and reliability.
There are now however now a lot of personality tests which do have good scientific credentials -- the "Big Five" etc.
I might declare an interest here. I have been a very active psychometrician. I suspect that I have had published more tests than anyone else. In just one article I published six different measures of six separate concepts -- all reliable and valid. Most of my work, however, was in the field of attitude measurement, not personality measurement. I did however make contributions to the measurement of anxiety, dogmatism and ambition (achievement motivation). See my categorized list of articles here. My measure of achievement motivation has proved particularly popular with other researchers
We tend to think of the Myers-Briggs Type Indicator as a frivolous internet distraction, akin to the hundreds of BuzzFeed quizzes that help us pass the time and think about ourselves in new (if not especially serious) ways. But in the mid-20th century, businesses used it as a powerful tool in hiring and management, changing the trajectories of many workers’ lives. What most of these businesses’ executives didn’t know was just how arbitrary the “science” behind the indicator was.
The Myers-Briggs Type Indicator was the brainchild of a mother and daughter, Katharine Briggs and Isabel Briggs Myers. They had no formal background in psychology or statistics, but they did have a fervent belief that their experiences as mothers and wives had taught them all about the innate, immutable power of personality types. Born in 1875, Katharine Briggs had always been fascinated by the idea of personality. She became a minor celebrity in the 1920s while writing parenting columns about how she educated her daughter, Isabel. When Isabel left for college, Katharine fell into a deep depression. It was then that she discovered the writings of Carl Jung, whom she called her “savior,” her “maker,” the “author of her life.” Over time, Katharine developed a way of categorizing people’s personalities using a variation of Jung’s theory of psychological types: introversion/extraversion, intuition/sensing, feeling/thinking, and to this she added perception/judging.
Her system never really caught on until her daughter, Isabel Briggs Myers, developed it into a 117-question marketable “indicator” — never a “test,” since there were no right or wrong answers, no good or bad types. Myers sold it to Edward N. Hay, a family friend and one of the first personnel consultants in the United States. With the rise of the labor force during and after World War II, newly established consultancies like Hay’s were warming to the idea of using cheap, standardized tests to fit workers to the jobs that were “right for them,” a match made under the watchful eyes of executives eager to keep both profits and morale high.
Personality tests spoke for more than just an individual person or company; they represented an emergent culture of white-collar work.
From the end of World War II to the beginning of the arms race in the early 1950s, news of the Myers-Briggs Type Indicator thundered through Pennsylvania, New York, and Washington, D.C. As men built bomb shelters and children practiced attack drills, Isabel picked up accounts, and these accounts began to double, even triple, in size. She took on large orders from colleges, government bureaus, and pharmaceutical companies; from Swarthmore, her alma mater; from her father’s longtime employer, the National Bureau of Standards; from the First National Bank of Boston, Bell Telephone, and the Roane-Anderson Company — a subcontractor for atomic weapons her father introduced Isabel to through his contacts on the Manhattan Project. She was not shy about asking for help or using her family’s connections.
Never one to miss out on an opportunity for self-promotion, Edward N. Hay wrote to his corporate client list on Isabel’s behalf, taking the credit for the indicator’s success despite his apparent lack of familiarity with its origins or the theory behind it. “The test is based on Jung’s Psychological Type-Mind,” he informed one client. “It was developed by Mrs. Isabel Briggs-Myers out of an experiment she did with me in 1942. I have used it in my consulting work quite a little.”
By the mid-1950s, Isabel’s clients were the largest utilities and insurance companies in the United States. They regularly spent upwards of $50 a year on test booklets and answer sheets. The Home Life Insurance Company of New York purchased it twice—first to determine whether an applicant would make for a successful life insurance salesman, and then to calculate whether a life insurance applicant should pay a larger premium on his insurance. (According to Isabel’s summary of her results, extraverted intuitive types — ENTPs and ENFPs — were more likely to exhibit risk-taking behavior.)