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What Does Research Say About The Enneagram Personality Typology System (EPS)?

Written by Rev. Andrea “Ani” Vidrine, LCSW

How legitimate is the enneagram personality typology system (EPS)? In 2021, researcher Joshua Hook and his colleagues set out to discover what is known about the EPS in the available scientific literature. According to the comprehensive literature review conducted by Hook et al. (2021), there are only 104 existing empirical studies on the EPS that are written in English. Hook et al. divided their task into five major components: a) examine the methodology of the available research studies, b) investigate how the enneagram types are determined, c) explore the correlation between the EPS and other personality typology systems, d) review the evidence for the concepts of wings and intertype movement, and e) consider the evidence for the EPS’ utility for personal/spiritual growth (concepts grouped together by the authors). The criteria for studies included in the authors’ review were that the research had to be empirical in nature and presented in English. No theoretical papers or case studies were included. The strategies employed for exploration of the literature included searching databases, examining the reference sections of relevant articles, reviewing all applicable articles from The Enneagram Journal, probing previous EPS literature reviews, and contacting primary research authors to inquire about available unpublishes studies. Utilizing these strategies yielded 104 articles that met the criteria (Hook et al., 2021).

According to Hook et al. (2021), approximately half of the relevant studies were published (n=49), the rest being comprised primarily of doctoral dissertations (n=41) and a small number of master’s theses (n=6), presentations (n=6), and unpublished works (2). Forty of the published studies were peer-reviewed, with 11 issued in The Enneagram Journal. The methodology displayed in the studies was quantitative (n=72), qualitative (n=19), and mixed-method (n=13). Hook et al. (2021) found only two studies employed an experimental design, with most of the research being either cross-sectional (n=70), longitudinal (n=26), or quasi-experimental (n=2).

To determine EPS type, Hook et al. (2021) observed that three measurements were utilized in EPS research: a) typing interview, b) self-report of type, or c) self-report measurements. The typing interview has not achieved industry reliability standards (Gamard, 1986) but does display construct validity (Daniels & Price, 2000). Self-reporting of type has been found to have some validity (Thrasher, 1994). The authors noted that self-report measurements, demonstrating mixed reliability and validity, were used in the majority of the studies: the Riso-Hudson Enneagram Type Indicator (RHETI; Riso & Hudson, 1999b); the Wagner Enneagram personality style scales (WEPSS; Wagner, 1999); and the Essential Enneagram test (EET; Daniels & Price, 2000). Of these, the RHETI and the WEPSS were most often employed (Hook et al., 2021).

In exploring the correlation between the EPS and other personality typology systems, Hook et al. (2021) observed that the Big 5 personality traits (n=9) and the Myers-Briggs (n=7) were the typologies most examined. There was a relationship identified between three to six enneagram types and each of the Big 5 traits, yielding what Hook et al. called “tentative support of the theoretical framework of the Enneagram” (p. 11). Of the studies comparing the Myers-Briggs and the EPS, the authors found “general support for the Enneagram framework” (p. 12). In reviewing the evidence for the concepts of wings and intertype movement, Hook et al. (2021) found that none of the relevant studies provided support for these concepts.

In considering the evidence for the EPS’ utility for personal/spiritual growth, while qualitative studies reported various mental, emotional, and spiritual benefits from working with the EPS, Hook et al. (2021) found mixed results in quantitative studies. According to the authors, “Some studies reported positive effects on variables such as self‐consciousness, communication competence, interpersonal relationships (Lee, 2015), anxiety, and self‐esteem (Rasta et al., 2012), but other studies reported no significant effects of Enneagram interventions on variables such as ego development (Daniels et al., 2018), psychological well‐being, and unconditional self‐acceptance (Godin, 2010)” (p. 12). In addition, Hook et al. (2021) noted that there were several studies that explored the efficacy of utilizing the EPS in the workplace, also yielding mixed results.

In discussing the results of their systematic literature review, Hook et al. (2021) highlighted three areas where more research is needed. First, the authors noted the need to have EPS measurements with stable reliability and validity. Second, the authors emphasized that the scant research on the EPS concepts of intertype movement and wings does not support these factors. Third, because the EPS has shown some benefit in personal/spiritual growth, the authors stated, “We believe a fruitful direction for research is to develop the Enneagram as a therapeutic tool” (p. 15). Additionally, the authors underscored one study that found correlations between enneagram types and attachment styles (Arthur, 2008) and suggested that future research in this area may lend credence to the EPS in conjunction with “a robust contemporary theory” (p. 14). Hook et al. (2021) concluded that while clinicians might best exercise prudence in utilizing the EPS because research is in its initial phases, EPS theory has the potential to meaningfully contribute to current psychological models, such as attachment theory.

So, should one trust the EPS in lofty goals like self-transcendence and personal growth? It seems that more research is needed to answer this question definitively. In the meantime, while not everyone finds benefit in working with the system, my personal experience has yielded a major increase in self-awareness and compassion for myself and others. Ultimately, the EPS is one of many available tools in the world’s psycho-spiritual growth tool kit; and not every tool is the right fit for each individual.

About the Author

Rev. Andrea “Ani” Vidrine, LCSW serves as a licensed clinical social worker, spiritual director, enneagram mentor, and interfaith/interspiritual minister. She has provided continuing education for counselors through, the NASW/Louisiana chapter, the Louisiana Association for Spiritual, Ethical, and Religious Values in Counseling, and dietitians through the Council on Renal Nutrition. Ani currently serves on staff at The Shalem Institute for Spiritual Formation in Washington, D.C. in their Spiritual Guidance program. For more information, please visit her website at


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