HEXACO: the sixth personality factor the Big Five leaves out

The Big Five is the best-known model of personality: openness, conscientiousness, extraversion, agreeableness and neuroticism. It grew out of studies of the words people use to describe each other, mostly in English. When the psychologists Michael Ashton and Kibeom Lee repeated that kind of study in several other languages, including Dutch, French, German, Hungarian, Italian, Korean and Polish, they kept finding a sixth factor. They called the resulting model HEXACO, after the first letters of its six factors.

The six factors

• H, Honesty-Humility: sincerity, fairness, avoiding greed, modesty. A high scorer does not manipulate people for gain and does not feel entitled to special treatment.
• E, Emotionality: fearfulness, anxiety, needing support from others, and sentimentality.
• X, Extraversion: social confidence, enjoying company, liveliness.
• A, Agreeableness: forgiveness, gentleness, flexibility, patience.
• C, Conscientiousness: organisation, diligence, perfectionism, carefulness.
• O, Openness to Experience: curiosity, creativity, an interest in art and ideas, an appetite for the unusual.

What changes compared with the Big Five

Three factors (extraversion, conscientiousness, openness) are close to their Big Five versions. Three things change.

Honesty-Humility is new. In the Big Five, sincerity and modesty sit loosely inside agreeableness. HEXACO gives them their own factor, and it predicts things the other five struggle with. Low Honesty-Humility is strongly linked with the "dark triad" traits of Machiavellianism, narcissism and psychopathy (Lee & Ashton, 2005).

Emotionality differs from neuroticism. Both include anxiety and worry. HEXACO Emotionality also includes sentimentality and the need for emotional support, and it leaves out anger.

Anger moves to Agreeableness. In HEXACO, someone low on agreeableness is quick to anger and slow to forgive. In the Big Five, quick temper counts towards neuroticism.

So the same person can get noticeably different results. A gentle person who worries a lot looks fairly similar in both models. A warm, sociable person who bends the rules for personal gain can score high on Big Five agreeableness and still score low on Honesty-Humility.

About our test

The HEXACO Personality Test uses 60 public-domain items from the IPIP-HEXACO scales (Ashton, Lee & Goldberg, 2007), ten per factor. Half of each factor's items are reverse-worded, so agreeing with everything does not inflate your scores. It takes about twelve minutes, and you get a score on each of the six factors.

These IPIP versions are free alternatives to the official HEXACO-PI-R questionnaire, which is a separate instrument. If you only want the sixth factor, the shorter Honesty-Humility test measures it on its own.

Which model should you use?

They answer slightly different questions. The Big Five has more research behind it and is the common language in psychology. HEXACO is worth taking when you are interested in fairness, trust and cooperation, at work or in close relationships. If you have already taken the Big Five test, HEXACO shows you how your result looks when honesty gets a factor of its own. If the dark side interests you, the Dark Triad test measures it directly. For more on the five-factor model, read the Big Five: what does it really say about you?.