

She codified her mother’s method of categorizing personalities, copyrighted it (in 1943), and spent the rest of her life trying to find a permanent home for the product. The daughter, Isabel Briggs Myers, was born in 1897. When she died, in 1968, the test she inspired was all but forgotten. The mother, Katharine Cook Briggs, was born in 1875. If they had not, there would be no MBTI today. They devoted their lives to their system, and they kept the faith for a very long time. To call them “mildly eccentric” would be indulging in a gender stereotype, but it seems fair to say that they were a little O.C.D. Briggs and Myers were a mother-and-daughter team. Merve Emre’s “ The Personality Brokers” (Doubleday) is the story of how the MBTI fell to earth. There are more than two thousand personality tests on the market, many of them blatant knockoffs of the MBTI, but Myers-Briggs is No. It is used by Fortune 500 companies and universities, in self-improvement seminars and wellness retreats. It is used in twenty-six countries to assess employees, students, soldiers, and potential marriage partners.

More than two million people take it every year. Katharine Briggs and Isabel Myers were the first kind, and the test they invented based on that belief, the Myers-Briggs Type Indicator, or MBTI, is the most popular personality test in the world. There are two kinds of people in the world: people who think there are two kinds of people in the world and people who don’t.
