History, Reliability and Validity of the MBTI^® Instrument

The Myers-Briggs Type Indicator^® (MBTI^®) instrument is the best-known and most trusted personality assessment tool available today. As many as 1.5 million assessments are administered annually to individuals, including to employees of most Fortune 500 companies.

The Myers-Briggs^® assessment has its roots in Carl Jung’s theory of psychological type. Katharine Briggs and her daughter, Isabel Briggs Myers, developed Jung’s theory and the first forms of the instrument, sharing a vision “to enable individuals to grow through an understanding and appreciation of individual differences in healthy personality and to enhance harmony and productivity among diverse groups. In developing their instrument, Briggs and Myers sought to sort personality preferences using the three dichotomies explicitly described in Jung’s writing, along with a fourth dichotomy made explicit by Briggs and Myers. These four dichotomies are:

• Extraversion (E) and Introversion (I): differentiating people who direct their energy primarily outward toward other people and events from people who direct their energy primarily inward toward their inner environment, thoughts and experiences
• Sensing (S) and Intuition (N): differentiating people who take in information primarily through the five senses and immediate experience from people who take in information primarily through hunches and impressions and are more interested in future possibilities
• Thinking (T) and Feeling (F): differentiating people who make decisions primarily based on logic and objectivity from people who make decisions primarily based on personal values and the effects their decisions will have on others
• Judging (J) and Perceiving (P): differentiating people who prefer structure, plans, and achieving closure quickly from those who prefer flexibility, spontaneity and keeping their options open

The MBTI^® instrument has been revised several times since it first appeared in 1942. New item formats and scoring methods were developed and tested first by Isabel Myers and later by professional psychometricians, with each revision leading to technical improvements over the previous form. The most recent forms are Form M and Form Q, both of which use item response theory (IRT)-based scoring and item selection.

Form M, first published in 1998, is the standard form for identifying an individual’s four-letter type. Based on results from a broad, nationally representative sample of 3,009 people, each of the four preference scales has internal consistency reliability of .90 or greater.

Form Q, first published in 2001, identifies an individual’s four-letter type and produces a more detailed representation of individual differences within type by reporting 20 facets. Based on results from a nationally representative sample of 1,378 people, median internal consistency of the 20 facets is .77.

Validity of both Forms M and Q has been examined through behavioral observations, exploratory and confirmatory factor analyses, correlations with related measures and even brain scans. For instance:

• Introverts spend significantly more time than Extraverts conducting “heads down” work, while Extraverts spend significantly more time doing work in open areas (Schaubhut, Thompson & O’Hara, 2008)
• INtuitives express significantly greater interest in Artistic occupations than Sensors (O’Hara, Thompson, Donnay, Morris & Schaubhut, 2006)
• Thinkers score significantly higher than Feelers on dominance, while Feelers score significantly higher on nurturance (Quenk, Hammer & Majors, 2001)
• Judgers score significantly higher than Perceivers on order, while Perceivers score significantly higher on change (Quenk, Hammer & Majors, 2001)

In fact, a research database maintained by the Center for Applications of Psychological Type (CAPT) lists more than 10,000 articles, books, and chapters relevant to the study of psychological type. Today, the MBTI assessment is available in 21 languages, with more translations and international research efforts in development. With its long and distinguished history, it continues to be used by people around the world to improve individual and team performance, explore careers, and reduce workplace conflict. Through these and other applications, the MBTI assessment is playing a part in the vision laid out by Briggs and Myers, helping people understand and appreciate themselves and others.

• Schaubhut, N.A., Thompson, R.C. & O’Hara, J.M. (2008). The influence of personality of where people choose to work. Poster presented at the Annual Convention of the American Psychological Association, Boston, MA, August 14-17, 2008.
• O’Hara, J.M., Thompson, R.C., Donnay, D.A.C., Morris, M.L. & Schaubhut, N.A. (August, 2006). Correlating the Newly Revised Strong Interest Inventory^® with the MBTI^®. Poster presented at the American Psychological Association Annual Conference, New Orleans, LA.
• Quenk, N. L., Hammer, A. L. & Majors, M. S. (2001). MBTI^® Step II™ Manual. Mountain View, CA: The Myers-Briggs Company, Inc.