HEXACO or MBTI – why the difference matters

When you turn a continuous scale into four letters, you lose the size of the differences. That is the most important structural difference between the six-factor model and MBTI. What is at stake becomes clear when you want to revisit your team's results a year later.

Categories lose information

MBTI forms sixteen categories from four preference pairs. The four-letter code is easy to remember and makes a good conversation starter at a team event. The six-factor model gives a 0-100 value on six dimensions and preserves the distances.

McCrae and Costa's 1989 analysis measured the MBTI scales against continuous personality dimensions. They found that the scales behind the preference pairs show meaningful covariation with the continuous traits. The contested point in the research is the categorisation itself. Part of the information is lost in the conversion to letters.

The logic of the two approaches

Two colleagues, two letters, barely different scores

Imagine two of your colleagues standing at almost the same point on the X Extraversion scale. They happen to sit on opposite sides of the category boundary. One gets an „E”, the other an „I”, as if they were opposites.

A third colleague stands thirty points away and still gets the same letter as one of them. The language of categories errs in both directions. It magnifies the small difference. It erases the large one.

Trita gives a label too – but it does not work from it

After all this, the question is fair: we name profiles ourselves. Trita forms a label from the two strongest dimensions. The dominant one gives the base, the second gives the modifier. That is how someone becomes an „Energetic Innovator” or a „Methodical Bridge-Builder”, for instance.

There are six base archetypes, and each can take five possible modifiers. That is thirty two-word labels. Six more cases come on top, where we use only the base, with no modifier. Thirty-six in total.

Those six base cases are the point. If the difference between the second and third strongest dimension is under eleven points, their order sits within measurement error. In that case we cannot say with confidence which one is stronger. The label stays without a modifier.

So the label is shorthand, not the result itself. It traces back to the six scores, it can be unpacked at any time, and it disappears the moment you look at the detail. A four-letter code, by contrast, is the result itself: there is nothing behind it to return to.

Honesty-Humility: what most questionnaires do not measure

H Honesty-Humility is the most distinctive addition of the six-factor model. Neither the classic Big Five nor MBTI has a separate equivalent. It brings together four areas: sincerity, fairness, the avoidance of greed, and modesty. As a leader, this is what lets you talk about fairness, status, and the pursuit of self-interest.

In 2019 Pletzer and colleagues summarised the research on the relationship between personality and counterproductive work behaviour. Honesty-Humility showed the strongest link among the dimensions studied. This is a moderately strong association. In plain terms it means that comparing large groups, groups with higher scores show on average fewer norm violations. It has to be added that many individual cases run counter to that tendency.

The 2019 meta-analysis by Lee, Berry and Gonzalez-Mulé measured the relationship with task performance. There a weak association came out. In practice this means you can barely infer professional performance from a personality score.

What follows in practice is that where internal diversity is large, it is worth talking about fairness and shared rules. The aggregate report gives a picture of the team as a whole. It does not show where anyone stands on the individual dimensions, and that is deliberate. We write about it at greater length in our article on the aggregate team profile.

Which one should you choose?

As a one-off conversation starter, MBTI works well too. If the goal is to build a shared vocabulary for a self-awareness workshop, the language of categories draws people in quickly. Participants generally enjoy it, and that can be worth a lot. Trita's labels can do this too, but MBTI offers a faster and simpler process.

Teamwork and later comparison need graded dimensions. This matters if you want to build on the results later. You might compare them with outside feedback, look at the distribution across a team, or repeat the measurement a year from now. All three need a measurement that preserves the size of the differences.

The publisher of MBTI also reports reliability data. The decisive difference is structural. A graded scale preserves more of the fine detail. And the point often lies exactly there.

Four questions worth asking

If you are choosing a questionnaire for your team, ask the vendor these four questions. The answers tell you more than the marketing material.

„Does the result give a degree or a category?” If a category, ask what happens to people standing near the boundary.

„In which language and on what sample was it validated?” A Hungarian translation of an instrument validated in English is not automatically a validated instrument. Adaptation is separate work.

„What does the reliability data show, and where does it come from?” Ask for a specific figure and a source. „Backed by research” on its own means nothing.

„What can the result not be used for?” A well-prepared vendor answers this quickly and concretely. If they have no answer, that is information in itself.

Sources and limitations

The findings discussed above are group-level meta-analytic averages. They show tendencies and do not predict individual behaviour. A low Honesty-Humility score does not prove unethical conduct, and on its own is not suitable for any HR decision.

In self-report form, both approaches can be distorted by response style and social desirability. Research findings about a model family do not automatically apply to every specific questionnaire. Trita's scale is a display format, and interpreting it also requires knowing the norms and the measurement uncertainty.

If the content of the six dimensions interests you, start with our article on the six-factor model.

• McCrae and Costa (1989): the relationship between MBTI and continuous personality dimensions
• Pletzer et al. (2019): meta-analysis of personality and workplace norm violation
• Lee, Berry and Gonzalez-Mulé (2019): meta-analysis of Honesty-Humility and job performance
• The MBTI publisher's summary on reliability and validity
• Official HEXACO scale descriptions

Trita builds on the six-factor model family and on public IPIP items. Research findings about the model family do not automatically validate our own item selection, Hungarian adaptation, scoring, or use for decision-making.