Construction of the MBTI^®

When Isabel Myers and Katharine Briggs decided to construct what became the Myers-Briggs Type Indicator^®, they operated from a number of presuppositions. The first of these was that Jung's typology was actually real, in particular his notion of attitudinal (Extraversion/Introversion) and functional (Thinking/Feeling; Sensing/Intuition) opposites.

Following on from that was the idea that people would be able to report their preferences through using a self report psychological inventory based on Jung's theory, recognising the differences between a theory of personality type and a theory of personality traits. The type/trait difference in looking at personality is significant as can be seen below:

Copyright Peter Geyer 1998. Enlarged and adapted from the work of Paul Kline ((1993) and Naomi Quenk (1993;1998)

Using this theoretical background, the practical requirements of constructing an instrument to reflect the theory led to the following strategies:

• selection of items that enabled people to select between the functional and attitudinal opposites; and
• testing and weighting items psychometrically so that choice of items would more easily reflect individual preferences, in particular precision in the centre of the scale so that persons with indeterminate preferences would be more likely to be classified according to their true preference

One of the consequences of these issues, as well as the need to identify Dominant and auxiliary functions as prescribed by Jung's theory, was the development of a second set of Attitudes (Judging/Perceiving) not found explicitly in Jung's theory, but in Myers and Briggs view implied in his writings on the subject.

Initially, questions that became part of the MBTI^® were constructed on small 3 x 5 cards and then tested by asking anybody that walked in the door of a Myers or Briggs residence. The information from these activities, combined with the large studies engaged in by Isabel Myers (assisted by her father who utilised his connections as Director of the Bureau of National Standards) and the facilities of the Educational Testing Service from 1949, further developed these questions.

One of the interesting sidelights of this research is that Isabel Myers conducted research on these items on males and females separately. A consequence of this was the separate scoring keys for male and female for today's MBTI^® forms.

Work on the construction and development of the MBTI^® is still continuing in order to make it more effective in applying type theory, in particular the development of other forms of the MBTI^®, including translation into other languages.

Photograph courtesy of Jamie Johnston, CAPT Library. PETER GEYER (INTP) is a consultant, researcher and writer in the field of C G Jung's theory of psychological types. He conducts MBTI Accreditation programs and presents internationally on a regular basis. Peter is a life member of AusAPT and a professional affiliate of the Australian Psychological Society.