Where these ideas come from

McCrae, R. R., & Costa, P. T. (1989). Reinterpreting the Myers-Briggs Type Indicator from the perspective of the five-factor model of personality. Journal of Personality, 57(1), 17-40. https://doi.org/10.1111/j.1467-6494.1989.tb00759.x

267 men and 201 women, reported as separate columns of Table 3, never pooled: with Extraversion, E/I r = -.74 (men) / -.69 (women); with Openness, S/N .72 / .69; with Agreeableness, T/F .44 / .46; with Conscientiousness, J/P -.49 / -.46 (scales scored toward I, N, F, P).

Furnham, A. (1996). The big five versus the big four: the relationship between the Myers-Briggs Type Indicator (MBTI) and NEO-PI five factor model of personality. Personality and Individual Differences, 21(2), 303-307. https://doi.org/10.1016/0191-8869(96)00033-5

N = 160; same four pairings; the facets named above; Neuroticism matched no MBTI scale.

Furnham, A., Moutafi, J., & Crump, J. (2003). The relationship between the revised NEO-Personality Inventory and the Myers-Briggs Type Indicator. Social Behavior and Personality, 31(6), 577-584. https://doi.org/10.2224/sbp.2003.31.6.577

N = 900; E .71 / I -.72 with Extraversion; N .64 / S -.66 with Openness; F .28 / T -.41 with Agreeableness; J .46 / P -.46 with Conscientiousness.

Furnham, A. (2022). The Big Five facets and the MBTI: the relationship between the 30 NEO-PI(R) facets and the four Myers-Briggs Type Indicator (MBTI) scores. Psychology, 13(10), 1504-1516. https://doi.org/10.4236/psych.2022.1310095

N = 9,487 managers; the same four pairings held but far weaker at domain level (E/I with Extraversion .20; T/F with Agreeableness -.35). Cited as a caution, not used in the map.

Hook, J. N., Hall, T. W., Davis, D. E., Van Tongeren, D. R., & Conner, M. (2021). 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

104 independent samples, mixed evidence of reliability and validity; nine studies related the types to the Big Five and the signatures here are the patterns that held in more than half of them, with counts.

Newgent, R. A., Parr, P. E., Newman, I., & Higgins, K. K. (2004). The Riso-Hudson Enneagram Type Indicator: Estimates of reliability and validity. Measurement and Evaluation in Counseling and Development, 36(4), 226-237. https://doi.org/10.1080/07481756.2004.11909744

N = 287; every RHETI type correlated with at least one NEO-PI-R factor; alphas .56-.82; factor analysis found Big Five-like factors, not nine.

Sutton, A., Allinson, C., & Williams, H. (2013). Personality type and work-related outcomes: An exploratory application of the Enneagram model. European Management Journal, 31(3), 234-249. https://doi.org/10.1016/j.emj.2012.12.001

N = 416, self-typed; each type had a distinct Big Five, values and motives pattern.

Bartram, D., & Brown, A. (2005). Putting the person into personality: SHL short research report 2005. SHL Group.

N = 241, self-typed, Big Five (OPQ32); one of the nine studies in the review.

Noftle, E. E., & Shaver, P. R. (2006). Attachment dimensions and the Big Five personality traits: Associations and comparative ability to predict relationship quality. Journal of Research in Personality, 40(2), 179-208. https://doi.org/10.1016/j.jrp.2005.01.003

Study 1 (BFI, N = 8,318): anxiety with N .42, E -.15, O -.07, A -.19, C -.23; avoidance with N .14, E -.21, O -.09, A -.22, C -.20. Study 2 (NEO-PI-R, N = 285): anxiety with N .52, C -.34; avoidance with E -.26, C -.23, N .17, O -.16. Big Five R-squared for the two dimensions .25 and .12.

Mikulincer, M., & Shaver, P. R. (2016). Attachment in adulthood: Structure, dynamics, and change (2nd ed.). Guilford.

the two-dimension model (anxiety, avoidance).

Fraley, R. C., Waller, N. G., & Brennan, K. A. (2000). An item response theory analysis of self-report measures of adult attachment. Journal of Personality and Social Psychology, 78(2), 350-365.

attachment is dimensional, not categorical.

Chapman, G. (1992). The five love languages: How to express heartfelt commitment to your mate. Northfield.

the five options, and only the five options.

Impett, E. A., Park, H. G., & Muise, A. (2024). Popular psychology through a scientific lens: Evaluating love languages from a relationship science perspective. Current Directions in Psychological Science, 33(2), 87-95. https://doi.org/10.1177/09637214231217663

no support for the matching effect; all five expressions tied to satisfaction; forced-choice measure unstable.

Johnson, J. A. IPIP-NEO data repository: the IPIP-NEO-300 public sample (307,313 screened protocols, answered online). Open Science Framework. https://osf.io/tbmh5/

the calibration sample. Every item in the bank was calibrated on it, so the line down the middle of every chart in a report is this sample's mean and one step on the scale is one of its standard deviations. Self-selected and answered online, most respondents young and English-speaking: a group we compare with, not the population, and no rank in it is reported.

Johnson, J. A. (2014). Measuring thirty facets of the Five Factor Model with a 120-item public domain inventory: Development of the IPIP-NEO-120. Journal of Research in Personality, 51, 78-89.

the facet codes N1-C6 used in this file are the IPIP-NEO facets the bank measures; NEO-PI-R names differ in places (E1 warmth = friendliness, O5 ideas = intellect, C6 deliberation = cautiousness).