Cognitive biases in hiring: what an objective test corrects (and what it does not)

Every recruiter believes they evaluate candidates objectively. That is precisely the problem: cognitive biases operate below the threshold of awareness, and the confidence we place in our judgement is not an indicator of its reliability. Which biases are most active in a hiring decision, and what can a standardised assessment protocol actually correct?

The illusion of validity: the founding bias

The psychologist Daniel Kahneman, Nobel laureate in economics, documented what he calls the illusion of validity: our confidence in our predictions about other people far exceeds their actual reliability. A smooth interview, good rapport, a feeling of "fit" produce a strong conviction, even though these signals poorly predict future behaviour on the job.

The illusion of validity is the founding bias of recruitment because it legitimises all the others: as long as the recruiter is convinced their intuition is reliable, they have no reason to support their decision with tools.

The four biases most active in a hiring decision

The halo effect

One salient characteristic (a prestigious degree, a well-known company on the CV, verbal fluency) colours the evaluation of everything else. The candidate who shines verbally is assumed to be rigorous, organised and collaborative, even though verbal fluency predicts none of those three competencies. The halo effect explains why two recruiters can defend opposite evaluations of the same candidate: each generalised from a different signal.

Confirmation bias

An impression forms in the first minutes of the interview, and the following questions then seek, often involuntarily, to confirm it. A positive prior leads to easy questions; a negative prior, to trick questions. The interview no longer measures the candidate: it documents the recruiter's first impression.

Similarity bias

We judge more favourably people who resemble us: same background, same codes, same references. This bias is the most costly at the scale of an organisation, because it produces homogeneous teams that reason the same way. It often disguises itself as "culture fit", which makes it socially acceptable and therefore harder to fight.

The contrast effect

An average candidate looks excellent after two disappointing interviews, and weak after a brilliant one. The order of interviews changes the evaluation, even though it says nothing about the person's competence. It is a structural bias of processes that rely on successive interviews without a common grid.

What a standardised protocol actually corrects

Research is clear on this point: you cannot debias a brain through goodwill alone. Awareness helps to spot risky situations, but the most effective lever is structural. It consists in changing the protocol, not the recruiter.

A standardised assessment protocol acts on three mechanisms:

• The same situations for everyone. When every candidate faces the same professional scenarios, the contrast effect and part of the halo effect lose their grip: you compare comparable responses, not successive impressions.
• Criteria defined before, not after. A competency grid defined upstream prevents rebuilding, after the fact, the criteria that justify the initial impression. It is the main antidote to confirmation bias.
• A measure independent of self-presentation. The Soft Skills Scan never asks about the competency itself: it places the person in concrete professional situations and analyses their responses, combining several assessment formats. Verbal fluency and likeability weigh less, the response in situation weighs more.

This movement joins a deeper shift in practices: according to APEC, 41% of companies recruiting executives now formally assess soft skills, up 9 points in one year. Structured assessment is no longer an avant-garde practice, it is becoming the standard.

What no test will correct for you

Scientific honesty requires saying what a protocol does not do.

The test does not decide. A score informs a decision, it does not make it. If the recruiter discards the result whenever it contradicts their intuition, confirmation bias has simply moved up one floor. The value of a protocol depends on the discipline with which it is used: the Soft Skills Scan is designed as a decision aid for the manager, never as an automatic verdict.

The test does not cover the whole process. Writing the job ad, screening CVs, the final negotiation remain moments where biases operate. An assessment protocol limits biases where it applies; it does not sterilise the entire journey.

The framework must be verifiable. An opaque tool displaces the problem instead of solving it: you replace the recruiter's bias with the vendor's black box. This is why Rising Up's framework of 18 behavioural competencies is published and available, while the assessment mechanics remain proprietary. What is measured can be audited.

From diagnosis to practice

Behavioural skills predict professional success, contribute to it causally, and can be developed (research by James Heckman, Nobel laureate in economics). It is precisely because the stakes are real that the quality of measurement matters: a biased signal on a decisive factor costs more than no signal at all.

Recognised as Deeptech by the European Innovation Council (EIC) in 2023, Rising Up built its assessment on contextualised professional scenarios and a public scientific framework, with one objective: giving recruiters an objective behavioural signal exactly where intuition alone is weakest.

To measure what this changes concretely in a hiring process, the Rising Up recruitment pilot lets you test the protocol on a real campaign, with your roles and your candidates. And to understand how objective assessment fits into a complete process, explore our approach to the recruitment test grounded in cognitive science.