Myers-Briggs Usage in Workplace Unsound, Scientist Says

"Although the MBTI is an extremely popular measure of personality, I believe that the available data warrant extreme caution in its application as a counseling tool, especially as consultants use it in various business settings," David Pittenger has written of the Myers-Briggs Type Indicator test. Pittenger is a psychology professor at the University of Tennessee at Chattanooga. He was responding to a pro-MBTI article in the same journal, Consulting Psychology Journal, written by Mary H. McCaulley. She was a former co-worker of the MBTI's co-creator, Isabel Briggs Myers, and leads an MBTI center.

McCaulley wrote a description of how the MBTI was created; the theories of psychology pioneer Carl Jung upon which the test is based; and its model of personality. "The gist of the theory is that much apparently random… human behavior is actually quite orderly and consistent, being due to certain basic differences in the way people prefer to use perception and judgment," McCaulley wrote. She says the MBTI tries to determine how a person prefers to become aware "of things, or people or occurrences or ideas," and come to "conclusions about what has been perceived." This results in classification of people according to four types. She goes on to point out that people who become top managers tend to be very different types from people who become counselors, and offers suggestions to help counselors who want to become business consultants on how to bridge the gap. She warns against some "misuses of type" including stereotyping and the use of results in hiring decisions. But, McCaulley concludes, "Counselors who wish to expand their counseling skills into consulting will find the MBTI a valuable tool to help the organizations and the people within them gain greater respect for their differences, work together more productively, and develop as individuals."

Pittenger responds, "I suggest that many of the uses of the MBTI, as endorsed by McCaulley (2000), lack empirical support, and that consulting psychologists should consider these facts before using the instrument." His first criticism is a point acknowledged by McCaulley, that MBTI suggests people can be grouped by clusters of personality traits in ways that makes them similar as a group and different from other groups. But this requires us to fall into "either/or" categories. More scientific personality tests, in contrast, view personality traits as a continuous range. In other words, you may be an introvert, or you may be an extrovert, or you may be somewhere in the middle. The MBTI agreed with this initially, according to Pittenger: "In an earlier version of the MBTI, individuals who scored at the center of one of the scales received an x rather than a letter code… The developers of the MBTI subsequently abandoned that practice and replaced it with a tie-breaking procedure to avoid assigning intermediate scores." In other words, the test forces you into a category even if you don't really fit one. Pittenger notes that McCaulley's data about what types tend to get into certain jobs does not tell you the degree to which those people differ, because it does not use continuous scales.

For mathematical reasons Pittenger details, this practice of the MBTI "may imply… significant personality differences where none exists" and means you cannot predict someone's behavior based on the test as well as you otherwise could. Another research team found it removes about 30% of the information the test could provide about someone. He quotes another researcher as saying, "'it would probably be better not to make these interpretations, or at least not rely on them heavily, with respect to important decisions about individuals.'"

Pittenger reports on several studies showing the results of the tests vary over short periods when retaken by the same people. One of the MBTI manuals reports a 35% change in type over 4 weeks, and another study reported 50% over 5 weeks. Also, at least nine studies have found the scales don't really produce the type groupings MBTI supporters claim, Pittenger says. That is, when you group the results based on math alone, the groups don't clearly match the groups the MBTI claims. Other sources, including an MBTI manual, show the test scales are linked (correlated). But they should not be related to each other if they measure separate parts of personality.

Other personality tests do not show the problems the MBTI does, Pittenger says. In particular, one called the Big Five is drawn mostly from the results of many studies over decades, whereas the MBTI is based primarily on Jung's theories developed decades ago and tries to fit test results to those. Pittenger adds, though, that no published study shows any other personality test is better "for predicting job performance or other work-related behavior." As long ago as 1996, Pittenger says, a review of studies on the MBTI in work situations showed that efforts to show simple links "'between type preferences and managerial effectiveness have been disappointing.'" Personality appears to only account for about 20% of the difference between people in work performance, he reports.

Pittenger warns that acting upon what you know about someone's type ignores how situations can change someone's thoughts and behaviors. Studies show that personality is only one factor in someone's decision style at a given moment. He writes from personal experience, "a wholesale application of the MBTI in an academic setting… resulted in the dissemination of dubious advice to students regarding their selection of courses and majors."

In contrast to McCaulley's 12 sources cited, almost all MBTI materials like manuals, Pittenger cites more than 50 sources, most from peer-reviewed journals.

Sources:

• McCaulley, M. (00), "Myers-Briggs Type Indicator: A bridge between counseling and consulting," Consulting Psychology Journal 52(2):117.
• Pittenger, D. (05), "Cautionary comments regarding the Myers-Briggs Type Indicator," Consulting Psychology Journal 57(3):210.