Making Sense of the MBTI–Enneagram Debate (part 1)

Author: Lisi Mallinson

In the world of personality assessment, two names frequently surface: the Myers-Briggs Type Indicator (MBTI) and the Enneagram. While the Enneagram enjoys popularity amongst non-psychological practitioners, and in the ongoing discussion of personality tools such as the MBTI (Neuroscience News, 2025), we’ve noticed some misinformation surrounding these tools. Our goal here is to address these concerns directly to provide clarity for our clients and the broader public.

As a supplier of the MBTI instrument, our core commitment is to support practitioners in meeting the highest standards of professional ethics and legal compliance in South Africa. Our focus is not on comparing products, but on ensuring that, at JVR Psychometrics, every assessment used to measure psychological constructs is supported by the requisite scientific evidence as provided for by section 8 of the Employment Equity Act. We must champion the use of scientifically sound tools to maintain the integrity of our practice and, most importantly, uphold our ethical responsibility to the public.

The non-negotiable requirement for evidence of psychometric properties

For registered psychologists and professionals in South Africa, the choice of assessment is governed by the ethical code of conduct, specifically the HPCSA’s Rules of conduct pertaining specifically to the profession of psychology (Form 223, Annexure 12). This requires all practitioners to be able to review, understand, and explain the psychometric properties – namely, the reliability, validity, and freedom from bias (measurement invariance) – of any instrument they use. These psychometric properties, typically provided in a comprehensive technical manual, are essential for demonstrating the instrument's scientific rigour and ensuring fair, accurate, and ethical application.

Our approach to transparency: The MBTI standard

The MBTI instrument is supported by decades of continuous refinement, global research, and extensive documentation. We make available a wealth of evidence demonstrating:

• Robust reliability: Consistent test-retest results over time.

• Established validity: Clear evidence that the instrument measures the intended psychological construct (psychological type preference).

• Unbiased use: Studies demonstrating its applicability and consistency across diverse cultural and linguistic groups.

We supply this information readily because it is paramount to the ethical use of any psychological tool. Providing practitioners with this verified, statistical evidence allows them to fulfil their professional duty and confidently defend their use of the MBTI in any professional or legal context.

The professional's due diligence

While we respect the popularity of many tools in the marketplace, such as the Enneagram, we urge all practitioners to exercise their professional and ethical obligation: The onus is always on the registered professional to request and review the scientific properties of any assessment they choose.

Any instrument that purports to measure personality, preference, or any other psychological construct must have this documentation available. When an assessment lacks accessible, verifiable evidence of reliability and validity, a professional cannot ethically or legally use it, regardless of its apparent face validity or how it is marketed. Our commitment is to ensure that professionals who choose the MBTI have all the necessary evidence to practice responsibly, effectively, and in full compliance with South African regulations.

The problem with the Enneagram: a lack of scientific accountability

The main argument against using the Enneagram, despite its reported face validity and popularity among non-psychology practitioners, rests on an absence of the verifiable scientific evidence that ought to accompany any measure of a psychological construct (Employment Equity Act, section 8).

• Is the Enneagram measuring a psychological construct? The Enneagram's theoretical basis is the "Enneagram of personality" and its reports market it as a personality and spiritual measure. By definition, this places it squarely within the domain of a psychological assessment. We also refer to the systematic review of the Enneagram by Hook et al. (2020), confirming that the application of the Enneagram is frequently used by clients to understand their personality and interpersonal patterns. Any claims that it is not a psychological tool—and therefore exempt from psychometric scrutiny—are scientifically unsound and should be rejected.

• The technical void: Even after purchasing The Wisdom of the Enneagram (by Riso and Hudson, the original developers of the assessment) and completing the Enneagram certification training, members of JVR Psychometrics could not find conclusive evidence of the assessment’s psychometric properties. The lack of a technical manual makes it extremely difficult to provide a completely objective, informed opinion on the tool, especially when other products that JVR Psychometrics usually advise on have these properties readily available to support our choice to promote and/or discourage assessment use. This makes it impossible for any professional to fulfil the ethical requirement of reviewing the Enneagram’s scientific rigor.

• Independent research raises flags: The systematic review by Hook et al. (2020) confirmed that the Enneagram is a measure of personality, making its use by unregistered individuals inappropriate. The review found mixed evidence of reliability and validity, and factor analytic work typically found fewer than nine factors. No work has used clustering techniques to derive the nine types. This suggests that the actual content of the questionnaire does not match its core theory of nine distinct types, fundamentally raising a question mark over its validity—i.e. what exactly is the Enneagram measuring?

In summary, the Enneagram’s fundamental scientific properties are either absent, contradictory, or unverified, which does not bode well for our legal and ethical duty to use instruments we can defend scientifically.

In part two of this series, we take a closer look at the most common criticisms of the MBTI itself—what’s valid, what’s misunderstood, and what the research actually says. We invite you to continue the conversation with us there.

References

Brown, Anna. (2015). Personality assessment, forced-choice. In J. D. Wright (Ed.), International encyclopedia of social and behavioural sciences (2nd ed.). Elsevier. DOI:10.1016/B978-0-08-097086-8.25084-8

Department of Health. (2006). Rules of conduct pertaining specifically to the profession of psychology (Form 223, Annexure 12 of the Ethical Rules of Conduct for Practitioners Registered under the Health Professions Act, 1974). Government Notice No. R. 717. Government Printers.

Hook, J. N., Hall, T. W., Davis, D. E., Van Tongeren, D. R., & Conner, M. (2020). The Enneagram: A systematic review of the literature and directions for future research. Journal of Clinical Psychology, 77(4), 865–883. https://doi.org/10.1002/jclp.23097

McLean, James & Chissom, Brad. (1986). Multivariate analysis of ipsative data: Problems and solutions. https://www.researchgate.net/publication/234705458_Multivariate_ Analysis_of_Ipsative_Data_Problems_and_Solutions

Neuroscience News. (2025, August 24). Personality tests like Myers-Briggs can mislead more than reveal. Neuroscience News. https://neurosciencenews.com/personality-tests-unreliable-29609/

Riso, D. R., & Hudson, R. (1999). The wisdom of the Enneagram: The complete guide to psychological and spiritual growth for the nine personality types. Bantam Books Inc.

South African Government. (1998). Employment Equity Act, No. 55 of 1998. Government Printers.

Van Eijnatten, F. M., Van Der Ark, L. A., & Holloway, S. S. (2014). Ipsative measurement and the analysis of organizational values: an alternative approach for data analysis. Quality & Quantity, 49(2), 559–579. https://doi.org/10.1007/s11135-014-0009-8