Not only do lawyers score very differently from the rest of the population on the Myers-Briggs Type Indicator (MBTI) (see Muir’s article "The Unique Psychological World of Lawyers"), but it appears that a lawyer was responsible for the development of the assessment in the first place. 

According to the Center for Applications of Psychological Types, Inc.  (CAPT),  the organization Isabel Briggs Myers established to research and maintain the assessment, the MBTI was developed by Katharine Cook Briggs and her daughter Isabel in the middle of the 20th century because of questions they had about Isabel’s husband, who was a lawyer.

Katharine’s father (Isabel’s grandfather) was on the faculty of Michigan Agricultural College (now Michigan State University) and her husband (Isabel’s father) was a research physicist who became Director of the Bureau of Standards in Washington. Isabel had a bachelor’s degree in political science from Swarthmore College, where she met and later married Clarence Myers, who became a lawyer.

Katharine first became interested in types because her son-in-law Clarence was so different from the rest of the family, CAPT reports. To try to help them both better understand Clarence, Katharine introduced Isabel to Jung’s book, Psychological Types, which was published in1921.

As they worked on the indicator during World War II, Myers’ and Briggs’ goal became “to show how our differences… can be valuable rather than divisive, and can be used constructively . . . to promote personal development . . . manage conflict and . . . increase human understanding worldwide,” and specifically to help women who were entering the industrial workforce for the first time identify the sort of war-time jobs where they would be "most comfortable and effective."

The Myers’ marriage was by all reports happy and long-lived, so Isabel’s inquiry into types may have proved productive not only for the greater world–where over 50 million MBTI assessments have been given, making it the oldest and most widely used personal style instrument.