The Myers–Briggs Type Indicator (MBTI) is an introspective self-report questionnaire with the purpose of indicating differing psychological preferences in how people perceive the world around them and make decisions. Though the test superficially resembles some psychological theories it is commonly classified as pseudoscience, especially as it pertains to its supposed predictive abilities.
The MBTI was constructed by Katharine Cook Briggs and her daughter Isabel Briggs Myers. It is based on the conceptual theory proposed by Swiss psychiatrist Carl Jung, who had speculated that humans experience the world using four principal psychological functions – sensation, intuition, feeling, and thinking – and that one of these four functions is dominant for a person most of the time. The test has consistent problems with repeatability, in addition to problems of whether or not it has exhaustive and mutually exclusive classifications. The four categories are Introversion/Extraversion, Sensing/Intuition, Thinking/Feeling, Judging/Perception. Each person is said to have one quality from each category, producing 16 unique types. The Center for Applications of Psychological Type claims that the MBTI is scientifically supported, but most of the research on it is done through its own journal, Journal of Psychological Type, raising questions of bias. As with the suggestion of ‘which chakra or zodiac sign is dominant’, the tests use of binary questioning and the similar popularity of the MBPT, specifically relies on the exploitation of the Barnum effect, a mix of flattery, followed by confirmation bias, to retroactively ‘fit the prediction’.
The MBTI was constructed for normal populations and emphasizes the value of naturally occurring differences. “The underlying assumption of the MBTI is that we all have specific preferences in the way we construe our experiences, and these preferences underlie our interests, needs, values, and motivation.”
Although popular in the business sector, the MBTI exhibits significant scientific (psychometric) deficiencies, notably including poor validity (i.e. not measuring what it purports to measure, not having predictive power or not having items that can be generalized), poor reliability (giving different results for the same person on different occasions), measuring categories that are not independent (some dichotomous traits have been noted to correlate with each other), and not being comprehensive (due to missing neuroticism). The four scales used in the MBTI have some correlation with four of the Big Five personality traits, which are a more commonly accepted framework.
The MBTI Manual states that the indicator “is designed to implement a theory; therefore, the theory must be understood to understand the MBTI”. Fundamental to the MBTI is the theory of psychological type as originally developed by Carl Jung.: Jung proposed the existence of two dichotomous pairs of cognitive functions:
- The “rational” (judging) functions: thinking and feeling
- The “irrational” (perceiving) functions: sensation and intuition
Jung believed that for every person, each of the functions is expressed primarily in either an introverted or extraverted form. Based on Jung’s original concepts, Briggs and Myers developed their own theory of psychological type, described below, on which the MBTI is based. However, although psychologist Hans Eysenck called the MBTI a moderately successful quantification of Jung’s original principles as outlined in Psychological Types, he also said, “[The MBTI] creates 16 personality types which are said to be similar to Jung’s theoretical concepts. I have always found difficulties with this identification, which omits one half of Jung’s theory (he had 32 types, by asserting that for every conscious combination of traits there was an opposite unconscious one). Obviously, the latter half of his theory does not admit of questionnaire measurement, but to leave it out and pretend that the scales measure Jungian concepts is hardly fair to Jung.” In any event, both models remain hypothetical, with no controlled scientific studies supporting either Jung’s original concept of type or the Myers–Briggs variation.