Skip to content

Big Five vs MBTI: why this choice?

FitRadarHR relies exclusively on the Big Five (OCEAN) model, never on the MBTI (Myers-Briggs Type Indicator). This page details why, with the sources backing this decision — it builds on the Big Five model presentation.

FitRadarHR never uses the MBTI

This is a non-negotiable rule of the product, not a preference: no feature relies on a scientifically unvalidated typology.

Two different logics

The MBTI sorts each person into one of 16 closed categories (for example "INTJ" or "ESFP"), based on 4 binary axes (Introverted/Extraverted, Intuitive/Sensing, Thinking/Feeling, Judging/Perceiving).

The Big Five does not sort anyone: it positions each person on 5 continuous scales (Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism). No one "is a type" — everyone sits somewhere on each dimension, and two people who are very close on the scale can end up artificially placed in opposite categories under a binary logic.

This difference in logic isn't just cosmetic: it's what explains most of the reliability problems measured on the MBTI (see below).

What the research says

Test-retest reliability

A reliable measurement instrument should give a stable result if retaken shortly after, absent any real change in the person. On this criterion, studies on the MBTI converge on a structural problem: between 39% and 76% of people change category on at least one axis when retaking the test after just a few weeks. A landmark study (Pittenger, 1993) reports that 50% of participants get a different classification on at least one of the four scales after a 5-week interval — with no real personality change expected over such a short period.

The Big Five, by contrast, is one of the most temporally stable personality models documented in psychometrics, with test-retest correlations generally above 0.80 over several weeks to several months.

Predictive validity

The Big Five is also the model with the most evidence of predictive validity — that is, its ability to predict concrete outcomes, not just describe. The landmark meta-analysis by Barrick & Mount (1991), covering 117 studies and five occupational categories, established that the Conscientiousness dimension consistently predicts job performance, regardless of occupation — a result replicated since by numerous subsequent meta-analyses.

The MBTI, by comparison, shows weak predictive validity for criteria such as job performance (correlations generally around 0.10 to 0.20) and insufficient convergent validity with the cognitive functions it claims to measure — meaning its own theoretical categories don't clearly show up in the data.

What the scientific bodies say

Pittenger's widely cited literature review (1993) concludes that the MBTI "does not conform to many basic standards expected of psychological tests." In the United States, the National Research Council (National Academy of Sciences) reached a similar conclusion regarding its use for employment-related decisions. In surveys of personality psychologists, only a minority (about 40%) consider the MBTI scientifically valid.

By contrast, the Big Five enjoys broad consensus in personality psychology research since the 1980s, with thousands of studies and consistent replication across dozens of countries and languages.

The MBTI still has defenders

Some more recent work (for example a meta-analysis by Capraro & Capraro, 2002) nuances the picture on test-retest reliability and reports more stable results over longer periods. The disagreement exists in the literature — but it concerns the scale of the problem, not its existence, and none of these studies restore the MBTI's predictive validity to the level of the Big Five's.

What this means concretely in FitRadarHR

Because the Big Five describes positions on continuous scales rather than closed categories, a FitRadarHR fit report never states that a person "is" a type incompatible with a position or a team. It shows a measured gap on each dimension, presented as a starting point for a conversation — never as a verdict. This is the same logic that forbids any automated decision score in the product: see the privacy and governance rules.

Sources

  • Pittenger, D. J. (1993). The utility of the Myers-Briggs Type Indicator. Review of Educational Research.
  • Barrick, M. R., & Mount, M. K. (1991). The Big Five personality dimensions and job performance: A meta-analysis. Personnel Psychology, 44(1), 1–26.
  • Capraro, R. M., & Capraro, M. M. (2002). Myers-Briggs Type Indicator score reliability across studies: A meta-analytic reliability generalization study. Educational and Psychological Measurement.
  • International Personality Item Pool (IPIP) — the Big Five questionnaire used by FitRadarHR, public domain.