The MBTI Was Not Created by Scientists
The Myers-Briggs Type Indicator is the most widely administered personality test in the world — used by approximately 88% of Fortune 500 companies, 200 universities, and millions of individuals annually. It was not created by professional psychologists. It was created by Katharine Cook Briggs, a homemaker and writer, and her daughter Isabel Briggs Myers, a mystery novelist — working largely from their living rooms, during World War II, without formal academic credentials in psychology. This history matters for understanding both the test's remarkable spread and its scientific controversies.
Katharine Cook Briggs: The Origin (1875–1968)
Katharine Cook Briggs developed her interest in personality typology in 1915, when her daughter Isabel brought home her fiancé, Clarence Myers. Katharine observed that Myers's personality was fundamentally different from anyone in her family — systematic, decisive, and outwardly focused where the Briggs family were reflective and values-driven. She began documenting personality observations across people she knew, constructing her own typology system that she called "The Four Types."
In 1923, Katharine encountered Carl Jung's newly translated Psychological Types and recognized her own framework as an imprecise precursor to Jung's more developed theory. She became a dedicated Jungian, corresponding with Jung and writing extensively about his typology in popular magazines. She saw it not as a professional project but as a personal mission: helping people understand one another to prevent the kind of cultural misunderstanding she believed had led to World War I.
Isabel Briggs Myers: The Instrument (1897–1980)
Isabel inherited her mother's project but transformed it. Where Katharine was philosophical, Isabel was practical and data-driven. During World War II, with millions of women entering the workforce for the first time, Isabel saw a specific problem: organizations had no systematic way to match people to jobs they'd be good at and find meaningful.
Beginning in 1942, she began developing an actual psychometric instrument based on Jung's typology. She had no formal psychology training — her degree from Swarthmore was in political science. She taught herself item-response theory, studied statistical methods, and collaborated with Edward Hay, a Philadelphia personnel manager, to test her instrument against actual job performance data in banking and manufacturing settings.
Her key innovation was the addition of a fourth dichotomy: Judging/Perceiving. Jung's original framework described three dimensions; Myers added a fourth to better predict how people prefer to organize their outer lives. This is explicitly not from Jung — it's her own contribution to the typological model.
The Instrument's Journey to Mass Adoption
Isabel published Form A of the MBTI in 1943. It circulated through word-of-mouth among HR practitioners and academics for decades. In 1975, Consulting Psychologists Press (later CPP, now The Myers-Briggs Company) licensed and began commercially distributing the instrument. Corporate adoption accelerated dramatically through the 1980s and 1990s as team-building workshops became standard practice in large organizations.
By the 1990s, MBTI had become a cultural phenomenon: the shorthand of "I'm an INTJ" entered common speech, and type descriptions circulated widely in books, magazines, and eventually the internet. The instrument was never primarily promoted through academic channels — it grew through HR practitioners, coaches, and organizational consultants who found it useful as a communication and self-reflection tool.
Carl Jung's Actual Influence on MBTI
Jung's 1921 Psychological Types described a framework of psychological functions: Thinking, Feeling, Sensing, and Intuiting — and an attitude dimension of Extraversion/Introversion. Isabel Briggs Myers operationalized these concepts into forced-choice questionnaire items and added the J/P dimension. The connection is real but imprecise:
- Jung never developed a questionnaire — his typology was clinical and observational
- Jung explicitly cautioned against rigid typing: "Every individual is an exception to the rule"
- The MBTI's four-letter type system doesn't directly correspond to Jung's more nuanced cognitive function theory, which involves dominant and auxiliary functions in a specific hierarchy
Critics (including many Jungian analysts) note that MBTI simplifies Jung's framework significantly. Proponents argue this simplification is what makes it practically useful.
The Scientific Controversy
Beginning in the 1980s, academic personality psychologists raised systematic concerns about MBTI's scientific foundations:
- Reliability: Multiple studies found that 50% of test-takers receive a different four-letter type when retested 4–6 weeks later (Pittenger, 1993)
- Bimodality problem: MBTI treats each dimension as categorical (E or I), but factor-analytic data consistently shows normal distributions — most people score near the midpoint, not at the poles
- Predictive validity: Meta-analyses found limited evidence that MBTI types predict job performance or team effectiveness (Furnham, 1996)
These critiques led to the development of the Big Five / OCEAN model as the dominant scientific personality framework. Take the free Big Five test on JobCannon to compare your scores against this research-validated alternative.
What the MBTI Does Well
Despite scientific critiques, MBTI persists for practical reasons:
- The type descriptions are positive and affirming — no "bad" types
- The framework is simple enough to apply in workplace conversations without a psychology degree
- The four-letter codes create shared vocabulary for discussing communication and work style differences
- For self-reflection purposes, the descriptions capture meaningful patterns even if the categories aren't scientifically precise
The MBTI Legacy
Isabel Briggs Myers spent 40+ years developing and refining the instrument before her death in 1980. Merve Emre's 2018 biography The Personality Brokers documents the full history with access to the Myers family archives. Her conclusion: MBTI's success reflects a genuine human need — the desire to understand oneself and others — more than its scientific properties.
Take the free MBTI test on JobCannon to experience the instrument with your own results. Understanding its history helps you use it accurately: as a self-reflection and communication tool, not a definitive scientific measurement of personality.
Conclusion: Remarkable Origins, Remarkable Reach
The MBTI is a 20th-century creation by two women without psychology degrees who believed that understanding personality differences could reduce human conflict. Whether or not you find its scientific foundations convincing, its cultural influence is undeniable — and knowing its actual origins helps you calibrate how to use it well.