How MBTI Evolved From 1925–1990
The Hidden History of a Global Typology
How MBTI Evolved From 1925–1990: The Hidden History of a Global Typology
The Myers–Briggs Type Indicator feels timeless today—an ever-present organizational tool that promises clarity about who we are and how we think. But the MBTI we know now didn’t appear fully formed. It was stitched together over the course of sixty-five years, from living-room observations in the 1920s to a globally recognized psychological instrument by 1990.
This article unpacks the real developmental arc: where the theory started, how it was reshaped, and why it looks the way it does today.
From Living-Room Notebooks to a Typology Framework (1920s)
Before MBTI existed, Katharine Cook Briggs began obsessively studying Carl Jung’s Psychological Types shortly after its 1921 publication. She typed her family and friends, kept notebooks, and developed working definitions of Jung’s ideas that were far more practical—especially the difference between Sensing and Intuition.
Crucially, at this stage there was no test, no data, and no formal theory beyond Jung. Briggs simply observed what she called “gifted” and “emergent” personalities and tried to distill their patterns. This was the seed from which MBTI would eventually grow.
Isabel Briggs Myers Takes Over and Adds a Fourth Dichotomy (1930s)
By the mid-1930s, Isabel Briggs Myers joined her mother’s work and expanded it. In the process of cataloging personality differences for practical purposes, she identified a distinction Jung never articulated: Judging vs. Perceiving.
This discovery is arguably the most important conceptual leap in MBTI history. It defined behavioral orientation—structure vs. flexibility—and allowed the eventual creation of the 16-type grid. Even though the instrument didn’t yet exist, the skeleton of modern MBTI was forming.
World War II: MBTI Is Born as a Practical Tool (1940s)
During WWII, Myers transformed decades of observations into an actual questionnaire designed to place women in industrial jobs. Suddenly, “type” was not hypothetical—it had to be measured.
The 1940s brought:
- The first real multiple-choice items
- The standard four-letter type codes
