Early in our ministry we were critical of personality testing and particularly alarmed at its use in Christian circles. At that time the personality testing movement was just a trickle in the church. Over the years this trickle has turned into a flood. To name a few areas, these tests are now used in Christian schools, Bible colleges, seminaries, and churches for selecting pastors and evaluating church staff compatibility.

In the PsychNotes of our January-February newsletter, we quoted from a description of a book by award-winning author Annie Paul, which is devoted to the subject of personality tests. The title of her book is The Cult of Personality: How Personality Tests Are Leading Us to Miseducate Our Children, Mismanage Our Companies, and Misunderstand Ourselves. The jacket cover of Annie Paul’s book summarizes well what she reveals in her book.

And she exposes the flawed theories and faulty methods that render their results unreliable and invalid. Personality tests, she contends, produce descriptions of people that are nothing like human beings as they actually are: complicated, contradictory, changeable across time and place.1

We have covered some of the same ground in our books and articles. If we were writing a book titled The Cult of Personality, our subtitle would be How Personality Tests Are Leading Christians to Miseducate their Children, Mismanage Christian Organizations, and Misunderstand Themselves.

In spite of our warnings and those of others, Christians have rushed pell-mell into personality testing. We agree with the statement on Annie Paul’s book cover that personality testing is a cult “that celebrates the superficial over the substantive, the static over the dynamic, the standard and average over the distinctive and unique.” As we have suggested, the Apostle Paul was no doubt a substantive, dynamic, distinctive, and unique individual who, by the worldly and fleshly standards of the personality-testing cult, would have been rejected for missionary service.2

Just as the church emulates the world in using and promoting psychological counseling theories and therapies, it emulates the world in the area of personality testing. Especially popular among Christians are spiritual gift inventories and tests. These are often used by church leaders who are trying to inspire Christians to serve and by those Christians who desire to serve the Lord. These various spiritual gifts tests (combinations of interest and personality inventories) purport to reveal a Christian’s particular spiritual gifts. We have already written critically about spiritual gifts inventories and the biblical and scientific reasons for not using them.3 Here we wish to examine the use of other types of personality tests.

There are probably thousands of personality tests available. According to its publisher, the Myers-Briggs Type Indicator (MBTI) is “the world’s most popular personality assessment.” It has been translated into numerous languages and there are chapters of the Association for Psychological Types all over the world. We know from surveys we have conducted that the MBTI is one of the most popular personality tests used in the church. The MBTI, or variations of it, is used by Bible colleges, seminaries, denominations, churches, and mission agencies, as well as by other Christian organizations and individual Christians.

Annie Paul says in her Introduction:

Perhaps no other personality test has achieved the cult status of the Myers-Briggs Type Indicator, an instrument created in the 1940s by a Pennsylvania housewife. Fiercely proud of the test she called “my baby,” Isabel Myers believed that it could bring about world peace—or at least make everyone a little nicer. The Myers-Briggs, which assigns each test taker a personality type represented by four letters, is now given to 2.5 million people each year, and is used by 89 of the companies in the Fortune 100. Employed by businesses to “identify strengths” and “facilitate teamwork,” the Myers-Briggs has also been embraced by a multitude of individuals who experience a revelation (what devotees call the “aha reaction”) upon learning about psychological type. Their enthusiasm persists despite research showing that as many as three-quarters of test takers achieve a different personality type when tested again, and that the sixteen distinctive types described by the Myers-Briggs have no scientific basis whatsoever.4

In addition to Isabel Myers, who developed the test, the Myers-Briggs Type Indicator is named after her mother, Katherine Briggs. The original idea of the types was a brainchild of the occult psychiatrist Carl Gustav Jung. Katherine Briggs read Jung’s Psychological Types and introduced her daughter Isabel to Jung’s typology.

After discussing Jung’s involvement in magic, alchemy, spirit guides, and other forms of occultism in our book Four Temperaments, Astrology & Personality Testing, we concluded the following:

At minimum, Jung’s theory, upon which the MBTI is based, is merely vain philosophies of men against which we are warned in Scripture. At worst, it originated from Satan through a spirit guide. We would think that no Christian would want Jung’s psychological theory or any test that derives from it.5

Nevertheless, numerous Christians and Christian organizations are using the MBTI. Thus we will now look at the scientific reasons for rejecting the MBTI.

The MBTI provides the following four bipolar scales:





These four scales yield 16 possible types.

The National Research Council has evaluated the MBTI. The Council members are drawn from the councils of the National Academy of Sciences, National Academy of Engineering, and Institute of Medicine. In appraising the MBTI, the National Research Council says:

It is probably fair to say that the MBTI is the most popular “self-insight, insight into others” instrument in use today. Unfortunately, however, the popularity of the instrument is not coincident with supportive research results.6

In other words, research results do not support the popularity! The Council also criticizes the marketing of the MBTI:

From the perspective of the instrument’s developers, the profits from an audience eager for self-improvement encourages them to market the instrument aggressively; aggressive marketing—complete with type coffee mugs, t-shirts, pins, license plates—has apparently increased the number of consumers worldwide.7

The Council report covers two of the most important areas in which to evaluate the MBTI or any other personality test. The two areas are “Reliability” and “Validity.”


One text describes reliability as follows: “Reliability refers to the consistency of scores obtained by the same persons when reexamined with the same test on different occasions.” 8

The council reports on a variety of studies that found that between 24 and 61 percent of MBTI test takers “showed stability of type.” In other words, they received the same MBTI type when reexamined at intervals ranging from five weeks to six years. However, that means that 39 to 76 percent were assigned a different type. The stability of type median was 40 percent, leaving 60 percent instability of type at the median. As a result, the Council report states: “Changes in type designations of these magnitudes suggest caution in classifying people in these ways and then making decisions that would influence their careers or personal lives.” 9


The validity of a test indicates its integrity, whether it actually measures what it is supposed to measure and how well it does so. One author of The Myth of Measurability says, “Validity is the soul of a test.” He also says, “It is here that most discussions of testing run aground and most informed proponents of tests fall silent.” 10

After discussing many studies on the validity of the MBTI, the Council report states:

The evidence summarized in this section raises questions about the validity of the MBTI. However, many users of the instrument have claimed that its value lies not in its diagnostic accuracy, which is problematic, but in its probative guidance. Respondents often emphasize the increased sensitivity gained from the discussions generated by MBTI feedback. It would seem that such gains could contribute to enhanced performance. Unfortunately, neither the gains in sensitivity nor the impact of those gains on performance have been documented by research. Nor has the instrument been validated in a long-term study of successful and unsuccessful careers. Lacking such evidence, it is a curiosity why the instrument is used so widely, particularly in large organizations.11

Others have expressed concern about the difficulty of establishing validity for tests that are based on theoretical constructs. Drs. L. J. Cronbach and P. E. Meehl say:

Unless substantially the same nomological net is accepted by the several users of the construct public validation is impossible. A consumer of the test who rejects the author’s theory cannot accept the author’s validations.12

In applying this idea to the MBTI, Dr. Jerry Wiggins says:

The validity of the MBTI can be evaluated independently of the total corpus of Jung’s writings but it cannot be fairly appraised outside the more delimited context of Jung’s theory of psychological types. As with any construct-oriented test, both the validity of the test and the validity of the theory are at issue.13

Please note that the validity of the test and the validity of the theory are inextricably bound.

Prior to their overall “Conclusions” section, the Council says that “the popularity of this instrument in the absence of proven scientific worth is troublesome.” In their “Conclusions” section, the Council says very clearly: “At this time, there is not sufficient, well-designed research to justify the use of the MBTI in career counseling programs.”14

In her Epilogue, Annie Paul says:

“An X-ray of personality.” Since the early days of personality tests, this has been the testers’ favorite metaphor, and no wonder: it calls to mind a precise and powerful instrument, capable of penetrating mere surfaces to produce an image of what’s within. And yet this metaphor has never been more than an alluring fantasy, or perhaps a willful delusion. The reality is that personality tests cannot begin to capture the complex human beings we are. They cannot specify how we will act in particular roles or situations. They cannot predict how we will change over time…. Personality tests do their dirty work, asking intrusive questions and assigning limiting labels….

But perhaps the most insidious effect of personality testing is its influence on the way we understand others—children, coworkers, fellow citizens—-and even ourselves.15

The “Barnum Effect,” Etc.

Why are people running after personality tests and inventories? And, why do Christians swallow the invalid and unreliable spiritual gifts tests? Research reveals that individuals are very prone to accept the most general character descriptions as being specifically applicable to themselves. The term given to this phenomenon is the Barnum Effect, named after P. T. Barnum, who believed that a good circus had “a little something for everybody.” Even though the descriptions or descriptive terms in the inventories, typologies, and tests apply equally well to other people, individuals are gullible enough to believe they are unique to themselves. Of course, this is exactly what happens with the horoscope, palm reading, and crystal ball gazing. This is known in research literature as the illusion of uniqueness and occurs at least for positive traits.

Besides the Barnum Effect there are other reasons why people believe in personality tests and types. When influential Christians and institutions promote these tests and when enthusiasm has been engendered, people tend to trust them. There is also a tendency to support a system in which one has invested time and money, even if the money is only the cost of a book. Unfortunately, the test user who becomes committed is the main source of others being enticed. The enthusiastic user becomes the enthusiastic promoter, often merely parroting the enthusiasm of the original promoter. It may be that the real Barnum Effect is Barnum’s comment, “There’s a sucker born every minute.”

Other reasons why people believe in personality tests and types include the “illusion of efficacy,” “illusory correlation, “self-deception,” “self-fulfilling prophecy,” “illusory thinking,” “numerolotry,” and “gnosis.” The appeal of gnosticism is in itself deceptive, because the heart is deceitful and desperately wicked (Jeremiah 17:9). As people look into themselves and as they use psychological devices for self understanding, they will consider themselves wise but they become fools as they fall for the deception.

The Bible has the truth about mankind. Personality tests, at their best, are a combination of information and misinformation, truth and fiction, cobbled together. We have recommended for years that Christians refrain from using personality tests and, if possible, refuse to take them. Understanding the self comes from the Bible, not from the imaginative and even educated guesses of humans, who are by nature self-deceived.

Christians should not administer or take the MBTI or its variations. For both biblical and scientific reasons, the MBTI and its variations should not be used to evaluate individuals for Christian service or for personal understanding. Contrary to the Bible, contrary to its apparent occult roots, and contrary to the scientific research, Christians and Christian organizations continue to use the MBTI and its variations. This cannot be pleasing to God!

PAL V13N2 (Mar-Apr 2005)

1 Annie Murphy Paul. The Cult of Personality. New York: Free Press, 2004.

2 Bobgan, Dear Friends Letter, January 2005.

3 Bobgan, “Spiritual Gifts Inventories,” PsychoHeresy Awareness Letter, Vol. 8, No. 4, <www.psychoheresy-aware.org>; and

Bobgan, Four Temperaments, Astrology & Personality Testing. Santa Barbara: EastGate Publishers, 1992, pp. 168-171.

4 Paul, op. cit., p. xiii.

5 Bobgan, Four Temperaments, Astrology & Personality Testing, op. cit., p. 154.

6 The National Research Council. In the Mind’s Eye. Daniel Druckman and Robert A. Bjork, eds. Washington: National Academy Press, 1991, p. 96.

Ibid., p. 101.

8 Anne Anastasi. Psychological Testing, 6th Ed. New York: Macmillan Publishing Company, 1988, p. 109

In the Mind’s Eye, op. cit., p. 97.

10 Paul L. Houts, ed. The Myth of Measurability. New York: Hart Publishing Company, Inc., 1978, p. 190.

11 In the Mind’s Eye, op. cit., p. 99.

12 L. J. Cronbach and P. E. Meehl quoted by Jerry S. Wiggins, “Review of the Myers-Briggs Type Indicator.” Tenth Mental Measurements Yearbook. Jane Close Conoley and Jack J. Dramer, eds. Lincoln: University of Nebraska Press, 1989, pp. 537-538.

13 Jerry S. Wiggins, “Review of the Myers-Briggs Type Indicator,” op. cit., p. 538.

14 In the Mind’s Eye, op. cit., p. 101.

15 Paul, op. cit., p. 221.