Personality Questionnaires

Personality instruments produce a profile that looks like insight. Their relationship with job performance is much weaker than their prominence suggests.

Once the criteria described in “Personality Questionnaires” are fixed, the practical challenge is running them consistently across assessors. A coordinator can use task time tracking to plan review time, compare the effort spent at each stage and spot avoidable delays, without confusing administrative efficiency with the quality of the evidence collected from candidates.

For an independent benchmark, compare the process with CIPD selection methods guidance; the useful test is whether the local method remains job-related, proportionate and explainable.

What the evidence supports

Conscientiousness relates to performance across many roles, consistently though not strongly.

Other traits relate to specific role types rather than generally.

And the effects are small enough that using a profile to choose between candidates is not defensible on prediction grounds.

The distinction that matters most

Instruments built on the five-factor model have research behind them.

Type-based instruments that sort people into categories do not, however widely used. They have poor test-retest reliability — people get different types on different occasions — and no demonstrated relationship with performance.

Using a type indicator for selection is not supportable, and several of their publishers say so explicitly in their own materials.

Faking

Candidates can and do answer as they think they should.

Instruments include detection scales with limited success.

Which means a selection context — where the incentive to present well is maximal — is the worst setting for these instruments, and better ones exist for the same decision.

What they can honestly contribute

A structured basis for interview questions. A profile suggesting somebody prefers autonomy gives you something specific to explore, which is a legitimate use.

Development conversations with people already hired, where the incentive to fake is absent and the purpose is self-understanding.

Team composition discussions, held lightly.

None of those is selection.

Using one anyway

Sometimes a decision has already been made above you.

Then: use it as input to an interview rather than as a score, do not set cut-offs, do not rank candidates on it, and make sure the final decision rests on the work sample and the structured interview.

And check adverse impact, because some instruments show score differences by group.

The candidate experience

Long questionnaires irritate people, particularly early in a process before any human contact.

A forty-minute instrument at the application stage loses candidates who had other options.

If you use one, put it later and explain why it is being used, which reduces both the dropout and the suspicion.

Accessibility and language

These instruments depend heavily on nuanced language and are usually validated in one language.

A candidate operating in a second language is answering a different instrument from the one that was validated.

Which is an argument against using them where your candidate pool is linguistically diverse.

What to check

Is your instrument five-factor based, or a type indicator?

Is it used as input to a conversation, or as a score?

Have you checked score differences by group?

And could you defend its use to a rejected candidate who asked why?

The point

Five-factor instruments have research behind them; type indicators do not.

A selection context is the worst setting for either, because the incentive to answer well is maximal.

Underlying all of this

Almost everything in this collection reduces to one discipline: write down what the job requires, assess that thing directly, record the evidence, and look at your own outcomes afterwards. None of it requires buying anything, and organisations that do those four things consistently outperform ones running longer processes built from instruments chosen before the requirements were known.