But the Myers-Briggs test had an intrinsic thematic quality that the others lacked. Most existing tests concluded that each personality category had a positive and a negative: An extrovert was good, an introvert was bad, for instance. But Myers felt that each personality type had strengths and weaknesses. Rather than build a test that favored one over another, hers was judgment-free. She and her mother described their personality types in terms of strengths and “gifts” and how those could clarify whether a person was the right “fit” for a job, a career or even a social affair. It felt simultaneously analytic and supportive, giving people a language to describe their best selves.
“We sometimes say that Isabel was the first positive psychologist,” Elizabeth Styron, chairwoman of the nonprofit Center for Applications of Psychological Types, an M.B.T.I. research center, said in a phone interview, referring to a branch of psychology that took off in the 1980s. “It’s about what’s right with a person, not what’s wrong with a person.”
The mother-daughter team became a creative sales force as well. Myers tweaked and promoted her product while searching for guinea pigs. Her son’s high school class took the test, as did incoming students to the George Washington University medical school. Soon dozens of medical schools around the country were added to her list. She wrote all the questions (for instance “Do you prefer to a) eat to live, or b) live to eat?”) and scored all the tests by hand.
All the while she pushed back against skepticism and sexism. Critics pointed out that neither Briggs nor Myers had a background or advanced degree in psychology; they were merely amateur “housewives” with an unusual hobby. And, the critics said, their personality indicator had no scientific foundation, no peer-reviewed research to validate it. Some said it was little more effective than reading someone’s horoscope.
Myers kept going nonetheless, and in 1956 she started working with Henry Chauncey, the president of the Educational Testing Service in Princeton, to publish the M.B.T.I. The tool posited that the four dimensions of personality produced a total of 16 possible types, all noted with initials.
The first dimension is whether an individual is an introvert (I) or extrovert (E). The second is how a person perceives the world, either through “sensing” (S) or through “intuition” (N). A third focused on how an individual makes decisions, either in a “thinking” (T) manner or a “feeling” (F) manner. The final dimension is based on how a person deals with the outside world, either “judging” (J) or “perceiving” (P). Judging is a structured, organized approach, while perceiving means someone has an adaptable, flexible, spontaneous relationship with the outside world.
Myers herself was a proud I.N.F.P., which she described as someone with a “great faithfulness to duty and obligations” who did not pass judgment on others. Her mother was an I.N.F.J.