Summary
Here are the key takeaways from our study:
Big Five Superiority: The Big Five personality test outperformed the Jungian (an MBTI-inspired framework) and Enneagram test in predicting life outcomes.
Neuroticism's Impact: Removing Neuroticism from the Big Five resulted in a substantial drop in predictive accuracy.
Trait Distribution: Most personality traits approximately formed bell curves, meaning that most people fall near the middle on each trait, suggesting binary categorization (as is typical with MBTI-style tests) might introduce substantial noise.
Continuous vs. Binary: Continuous scores in the Jungian framework predicted outcomes substantially better than binary categories (which is important since MBTI-style tests are usually presented in a categorical form).
Jungian Limitations: The Jungian 4-letter framework showed less predictive accuracy than the Big Five, mostly due to its use of binary types (splitting participants into letters like I vs. E and N vs. S) and its failure to measure Neuroticism. By adapting the Jungian framework to give continuous scores (rather than categories) and excluding Neuroticism from the Big Five, then the predictive gap between the two frameworks narrows. However, even with these adjustments, the Big Five (without Neuroticism) still slightly outperformed the modified Jungian test (with continuous scores, not binary types).
Cross-framework Relations: Almost every Jungian trait correlated with a specific Big Five trait: the Jungian Extraversion/Introversion aligned with Big Five’s Extraversion, Intuition/Sensing with Openness, and Feeling/Thinking with Agreeableness. However, the Judging/Perceiving trait was associated with three of the Big Five traits.
Integration Ineffectiveness: Combining Big Five and Jungian test results didn't improve prediction accuracy over using just the Big Five alone. This suggests that the Jungian test does not add significant predictive value beyond what is already captured by the Big Five.
Enneagram's Surprisingly Good Performance: Despite its simplicity, the Enneagram binary (where we used only the 1-digit Enneagram as variable e.g., Type 9) performed better than the binary Jungian Type at predicting life outcomes. However, the Enneagram still underperformed the Big Five.
Participant Perception: Despite the Jungian test’s lower predictive accuracy, participants felt better after reading their Jungian assessments than their Big Five assessment, likely due to the Jungian test's positive framing — it’s better to be called “Thinking” than “with low Agreeableness”.