The Big Five's empirical record
The Big Five (Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism) has accumulated one of the largest longitudinal empirical records in personality psychology. **Job performance**: Conscientiousness is the single strongest personality predictor of job performance, with corrected correlations around r = 0.31 across occupations (Barrick, Mount & Judge 2001 meta-analysis covering >115,000 individuals). Emotional Stability (low Neuroticism) adds a smaller but real effect. No other personality dimension predicts work performance as robustly. **Relationship satisfaction**: low Neuroticism and high Agreeableness predict better relationship outcomes. Multiple longitudinal studies show Neuroticism as a substantial risk factor for relationship dissolution (Kelly & Conley 1987; Karney & Bradbury 1995 and subsequent). **Longevity**: Conscientiousness predicts longevity in the original Terman sample followed for 80+ years (Friedman et al. 1993 and subsequent), adjusting for confounders. The "longevity project" remains one of the strongest demonstrations of personality's life-course impact. **Physical health**: Conscientiousness and low Neuroticism predict health outcomes (cardiovascular disease, metabolic syndrome, infection resistance) across dozens of studies. **Academic achievement**: Conscientiousness predicts GPA with effects comparable to cognitive ability in some samples (Poropat 2009 meta-analysis). **Therapy response**: Neuroticism and Openness predict therapy outcomes across modalities; Neuroticism predicts the magnitude of pre-treatment distress and symptom severity; Openness predicts engagement with depth-oriented therapies.
MBTI's predictive record
MBTI has a much thinner predictive record. This is not because MBTI hasn't been studied — it has, extensively — but because the findings are weak relative to Big Five benchmarks. **Job performance**: the 1991 National Research Council report on the MBTI (Druckman & Bjork) found minimal evidence for MBTI's predictive utility in occupational settings. Subsequent studies have not substantially changed this picture. When MBTI dimensions do predict outcomes, the predictive variance typically overlaps with Big Five dimensions (E, N, O, C) that MBTI shares. **Relationship outcomes**: no replicated evidence of specific MBTI type-combinations predicting marital satisfaction. Attachment style predicts relationship outcomes far more reliably. **Academic achievement**: some studies find small effects for specific MBTI dimensions on GPA, typically attributable to the Conscientiousness-related variance in J/P. **Health / longevity**: no substantial findings. **Therapy response**: minimal; practitioners using MBTI clinically rely on its orientation function rather than its predictive validity. The pattern: where MBTI predicts anything, the prediction typically comes from the Big Five variance it happens to capture, not from the type code itself.
Why the Big Five predicts better
Three structural reasons for the gap: **1. Empirical derivation**. The Big Five emerged from lexical analysis — researchers examining personality-descriptive words across languages and extracting the factors that kept reappearing. This is bottom-up. MBTI was top-down — derived from Jung's theoretical framework and operationalized without prior empirical factor analysis. Bottom-up instruments tend to validate better than top-down ones. **2. Continuous scales**. Big Five scores are continuous across each factor. MBTI forces binary categorization at each dimension cutoff, destroying information. When research uses continuous MBTI preference scores rather than type codes, predictive validity improves — but this defeats the point of the type-based framework. **3. Coverage of Neuroticism**. Neuroticism is the single most clinically consequential personality dimension. It predicts mental health outcomes, relationship problems, and therapy response. MBTI has no equivalent. This is a systematic gap in MBTI's coverage of the personality space, and much of Big Five's predictive advantage comes from having Neuroticism in the model at all.
When to use each
**Use Big Five when**: - Making decisions that matter (career fit, high-stakes hiring, treatment planning) - Wanting clinical-level precision - Predicting actual life outcomes - Assessing risk factors for mental or physical health - Conducting research **Use MBTI when**: - Starting conversations about personality differences in low-stakes contexts (teams, relationships) - Entering Jungian cognitive-function theory for self-reflection - Generating rough temperament orientation (NT/NF/SJ/SP level) - Reading evocative type descriptions for pattern recognition - Early-stage meditation method selection **Use neither alone when**: - The stakes are very high (mental-health crisis assessment; major life decisions). Use clinician-administered instruments like the NEO-PI-R, MMPI-2, PAI.
Which to take first if you're starting from scratch
Take the Big Five first. Specifically, take the IPIP-NEO (International Personality Item Pool - NEO) 120-item version, freely available at ipip.ori.org. This gives you facet-level scores on all five factors in about 15 minutes. It's the best single personality instrument a non-clinician has access to for free. Then take the MBTI for temperament orientation. If you want more precision than the standard 4-letter type output, take a cognitive-function assessment (Dario Nardi's Keys 2 Cognition) instead of or alongside the MBTI. Then reconcile. Where the two instruments agree, the signal is robust. Where they disagree, the Big Five is probably closer to the underlying trait structure but the MBTI's cognitive-function language may be useful for how you articulate the pattern. For specific uses like meditation method selection, the MBTI/cognitive-function framework is more directly applicable than Big Five because traditional method-fit recommendations developed within Jungian type theory. Big Five is better for general life prediction; MBTI is better for specific contemplative-practice application.
The overall honest position
Neither MBTI nor Big Five captures personality completely. Both are working models that produce useful approximations at different levels of precision. The Big Five is what to use when it matters. MBTI is what to use when it's useful but the stakes are low. These are not competing but complementary. A sophisticated user takes both, uses Big Five for decisions, and uses MBTI for vocabulary and orientation. The common mistake is using MBTI where Big Five should be used (hiring, significant clinical work, relationship matching). Don't make this mistake. The cost of using the wrong instrument at high-stakes decision points can be very large. The rarer but real mistake is using Big Five where MBTI would actually serve better — specifically in contemplative-practice orientation, where the Jungian cognitive-function framework still provides the most traction. A pure Big Five orientation misses the method-fit dimension that Jungian theory gave us.