Personality tests for hiring designers

The desirable answer is always obvious

Nobody applying for a collaborative role selects “I prefer to work alone and rarely seek feedback”. Self-report instruments assume good-faith introspection, and a hiring process is the one situation where that assumption is least safe.

What you end up measuring is the candidate's model of what you want. That's a skill too, just not the one on the job description.

Selection and development are different uses

Used after hiring, to help a team understand how its members prefer to work, the better instruments are useful and largely harmless. The failure is using them as a gate.

As a gate they carry legal exposure that varies by jurisdiction but is never zero, particularly where a trait correlates with a protected characteristic or the instrument has never been validated for the role in question.

What senior candidates read into it

Experienced designers recognise a personality questionnaire in a hiring flow immediately, and a meaningful proportion of them withdraw. Abstract principle has little to do with it. The questionnaire signals that the company can't assess the work and is looking for a proxy.

That signal is often correct, so take it seriously.

Measure the behaviour instead

Everything a personality test is trying to get at can be observed directly, if you put the person in the situation and ask for the artefact.

Instead of asking how someone handles disagreement, put a stakeholder in front of them who has decided the answer and won't move, and ask them to write the reply. Instead of asking whether they take feedback well, criticise their proposal halfway through the exercise and see what they do with it.

You end up with words you can read and judge, rather than a trait score you have to take on faith.

The five interpersonal signals worth capturing

Each of these can be observed inside a work task, and each produces an artefact you can read.

• Explaining a decision to someone outside the discipline, without jargon.
• Handling disagreement with a senior stakeholder who won't move.
• Taking hard criticism mid-task: do they revise, defend, or collapse?
• Working with an engineer who says the approach isn't possible.
• Self-awareness: naming the weakest part of their own proposal.

What the research says, in both directions

People selling something else tend to overstate the case against personality testing in hiring, so here's the fair version.

Personality measures do predict job performance: modestly, consistently, and better than an unstructured interview. Conscientiousness in particular shows a small positive relationship with performance across most job families, and it has held up across decades of study. Anyone telling you these instruments measure nothing is wrong.

Validity holds up; application is where it breaks. A small average effect across thousands of people is a solid finding and an almost useless basis for deciding between two particular candidates, because the variation between individuals swamps it.

A signal that shows up in a population is different from a signal you can act on in a room.

And most hiring processes don't use the instruments the research validated. A four-letter type indicator isn't a Big Five inventory, doesn't have its psychometric properties, and was never designed for selection. Its own publisher says so.

The specific failure mode in design hiring

Design teams reach for personality testing at a predictable moment: when the shortlist is technically strong and someone asks “but will they fit here?”. That's a fair question, and this is the wrong instrument for it.

By fit, the team usually means one of three things: will they cope with our level of ambiguity, will they push back or go silent, will they survive the review culture. All three are situational. They depend on the environment as much as the person, and the same designer can be excellent in one and miserable in the next.

A trait score can't answer a situational question. It gives the discomfort a number instead, and a number is very hard to argue with.

That's how a team ends up rejecting a strong candidate for being “too low on agreeableness” when what happened was that one interviewer found them abrupt.

If you're going to use one anyway, five rules

Sometimes the decision isn't yours, or the instrument is already in the process. These rules keep it from doing damage.

• Never use it to screen out. Use it after the decision to hire, to inform how you manage and onboard the person. That's the use these instruments were built for and where they hold up.
• Never let it break a tie. If two candidates are close on the things that matter, a trait difference is noise, and using it to decide feels rigorous while being arbitrary.
• Decide what the profile means before you see anyone, and write it down. Otherwise the profile gets interpreted to support the preference that already exists.
• Use an instrument with published psychometric properties, and read them. If the vendor can't tell you the reliability coefficients or what it was validated against, it's a personality quiz with a sales team.
• Tell the candidate what it's for and what you'll do with the result. If that sentence is uncomfortable to write, the discomfort is telling you something about the use.

What to measure instead, and how

Everything a team wants from a personality test is available from behaviour, and behaviour is both more predictive and easier to defend.

Ambiguity tolerance: give them a brief with a hole in it. Do they ask, assume and flag the assumption, or build something and hope? All three happen, they look visibly different, and no self-report question distinguishes them.

Conflict behaviour: ask about a decision they lost. Skip the general question about handling conflict, which everyone answers identically and well. Ask about one occasion, what they did afterwards, and whether the work continued. The general question measures composure in interviews; the concrete one tells you what happened.

Feedback response: give real critique on something they presented, in the interview, and watch. It's uncomfortable, and it's the most informative thirty seconds in most design hiring processes, because it's the one moment the candidate can't have rehearsed.

Frequently asked

Is MBTI acceptable for hiring?

No serious practitioner recommends MBTI for selection. Its test-retest reliability is poor enough that a meaningful share of people get a different type weeks apart, and it was never designed as a selection instrument.

What about cognitive ability tests?

That's a different question with a different evidence base: general cognitive ability is among the better-supported predictors in the research. These tests come with their own fairness considerations, but they don't belong in the same category as self-report personality inventories.

Are personality tests legal to use in hiring?

In most jurisdictions yes, with conditions that vary and that tighten considerably where a result could be read as health-related information. In the EU, automated decisions that significantly affect someone carry obligations of their own, including the right to human review. This isn't legal advice. If a personality result contributes to rejections, that's a decision you need to be able to explain and defend, and many teams using these tools have never checked whether they can.

What about culture-fit assessments? Are those different?

Usually it's the same instrument with a friendlier label. What matters is what happens to the result: if a low score removes someone from the process, it's a selection instrument whatever it's called, and it carries every problem described above.

Do situational judgment tests have the same problem?

They have a different one. An SJT measures a decision in a described situation rather than a trait, so it's tied to the job rather than to the person. The desirable answer can still be guessable if the options aren't built carefully. So a well-built one offers no obviously correct option: every choice has to be something a reasonable professional might do, or you're measuring who guessed what you wanted.