The Big Five is the gold standard of personality psychology. Decades of cross-cultural research, strong predictive validity for job performance and relationship satisfaction, and a clean five-factor structure that holds up across languages and populations. If you know your OCEAN scores, you know something real about your personality.
HEXACO is what comes after you know the Big Five well enough to see what it's missing.
What the Big Five measures
The Big Five — Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism — emerged from factor analysis of personality-descriptive adjectives. Researchers asked: if you look at all the words people use to describe personality in natural language, what structures emerge? Across many languages, five factors kept appearing.
The model predicts meaningful outcomes:
- Conscientiousness is the strongest personality predictor of job performance across virtually every occupation studied
- Neuroticism predicts depression, anxiety disorders, and relationship dissatisfaction
- Extraversion predicts leadership emergence and social network size
- Agreeableness predicts cooperation and relationship quality
- Openness predicts creative performance and intellectual curiosity
This is well-validated science. But researchers working across more languages noticed a problem.
Why researchers weren't satisfied with five factors
When personality psychologists Kibeom Lee and Michael Ashton extended the lexical analysis to Korean, Hungarian, Filipino, and several other languages, the five-factor structure didn't replicate as cleanly. A sixth factor kept emerging — one that captured something the Big Five didn't cover well.
They called it Honesty-Humility.
Honesty-Humility captures sincerity, fairness, modesty, and the avoidance of greed. People high in Honesty-Humility avoid manipulating others, don't exploit situations for personal gain even when they could get away with it, and don't feel particularly entitled to special treatment. People low in Honesty-Humility are comfortable with deception, feel entitled, and will bend rules when it benefits them.
The resulting model — HEXACO — keeps five factors largely intact and adds Honesty-Humility as the sixth.
The key differences between HEXACO and Big Five
The frameworks aren't just "Big Five plus one." Adding Honesty-Humility required some reorganization of how traits are distributed across the other dimensions.
Agreeableness in HEXACO is narrower than in the Big Five. The Big Five's Agreeableness includes cooperativeness, trust, and warmth — some of which overlaps with honesty and fairness. In HEXACO, the moral fairness content moves to Honesty-Humility, leaving HEXACO Agreeableness to capture patience, forgiveness, and gentleness more specifically.
Emotionality in HEXACO corresponds to Big Five Neuroticism, but with different emphasis. HEXACO Emotionality focuses more on fearfulness, anxiety, and emotional dependence; Big Five Neuroticism captures emotional instability and negative affect more broadly. A person who is temperamentally irritable but not particularly fearful would score high on Big Five Neuroticism but lower on HEXACO Emotionality.
Conscientiousness, Extraversion, and Openness are largely consistent between the two frameworks, with minor facet-level differences.
What Honesty-Humility predicts that the Big Five cannot
This is the most important practical difference between the two models.
The Big Five predicts performance, relationships, and health outcomes well. What it predicts poorly is ethical behavior under competitive pressure — specifically, what someone does when they could exploit a situation, bend a rule, or misrepresent themselves and face no immediate consequence.
Honesty-Humility predicts this category of behavior better than any Big Five dimension. Research shows it correlates with:
- Lower rates of counterproductive workplace behavior — theft of time, rule-bending, misrepresentation — after controlling for conscientiousness
- More equitable behavior in economic games, even in anonymous conditions where cheating carries no consequence
- Reduced Machiavellianism — the strategic exploitation dimension of the Dark Triad
- Lower likelihood of occupational fraud in workplace studies
- Greater fairness in competitive negotiations, even when unfairness would go undetected
The reason is conceptually clear. Conscientious people are organized, reliable, and goal-directed. Agreeable people are cooperative and warm. But neither trait reliably predicts what a person does when their interests conflict with others and enforcement is absent. A conscientious person can be strategically dishonest. An agreeable person can still pursue self-interest in ways they conceal. Honesty-Humility measures the underlying orientation that determines behavior when no one is watching.
When Big Five is sufficient — and when HEXACO matters more
For most everyday personality questions, the Big Five is sufficient:
- Career fit and job performance: Conscientiousness and its facets predict most occupational outcomes
- Relationship quality: Agreeableness and Neuroticism are the primary relationship predictors
- Creative and intellectual work: Openness
- Social and leadership contexts: Extraversion
HEXACO adds meaningful predictive power for:
- Ethics and integrity under pressure: Any context where rule-following is optional
- Business partnerships and negotiations: Whether someone will exploit an advantage
- Leadership in high-trust environments: Whether someone will maintain standards when it costs them
- Long-term relationship trust: Not warmth, but whether the person will be fair when fairness is tested
- Self-awareness about your own ethical defaults: The dimension most people haven't examined
Practically speaking: if you're trying to understand how someone performs, the Big Five is what you need. If you're trying to understand how someone behaves when no one is checking, you need Honesty-Humility.
The measurement problem both models share — and one approach to solving it
Both Big Five and HEXACO face the same fundamental challenge when measured by self-report: you're asking people about themselves, and self-report is shaped by how people want to be seen.
This creates a particular problem for Honesty-Humility. The people with the lowest Honesty-Humility scores are precisely the people most likely to inflate their scores. If you're the type of person who bends rules for personal advantage, you have both the motivation and the skill to answer "I would never exploit someone for personal gain" on a questionnaire.
This is why Memrov measures HEXACO — along with the Big Five and four other frameworks — from behavioral data rather than self-report. Your exported AI conversation history carries Honesty-Humility signals in how you reason through ethical situations, how you describe your own behavior relative to others, how you frame competitive dynamics, and whether you apply consistent standards to yourself and to other people. These patterns emerge across hundreds of conversations and aggregate into a more stable signal than any questionnaire response.
The person who has never thought about HEXACO is still expressing it every time they interact with an AI about a situation involving fairness, competition, or conflicting interests.
Which framework should you know?
The short answer: both.
The Big Five gives you the foundation. It tells you where you sit on the dimensions that predict the most about your professional performance, relationship patterns, and emotional tendencies.
HEXACO adds the dimension the Big Five leaves open. It tells you something about your ethical defaults — the orientation that operates when external enforcement is absent.
Most personality tests give you one or the other. Memrov measures both — along with attachment style, Schwartz values, Dark Triad, and motivation patterns — from a single upload of your AI conversation history. Because understanding personality well requires more than five numbers, and because the most important dimension is often the one people never think to measure.
Get your Big Five and HEXACO profile — scored from your conversation history, free →