Interview bias explained, and how to prevent it

Joe Caccavale






min read


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Interview bias: as humans, we’re subject to unconscious biases - mental shortcuts that lead us to make snap judgments and associations. Whilst we need this quick-fire thinking to get us through the day, it can prevent us from being objective and making accurate judgments. In interviews, candidates are often overlooked or unfairly favoured based on factors that have nothing to do with their actual ability.  

First impressions matter - even though they shouldn’t

As soon as candidates set foot through the door (or pop up on Zoom), your brain starts making associations and misfiring in all sorts of ways.

If you consider the fact that the average CV review takes just 7.4 seconds... 

You can imagine how quickly we make up our minds about a candidate in an interview.

According to one study, roughly 5% of decisions were made within the first minute of the interview, and nearly 30% within five minutes.

Here are some of the interview biases that you can expect to kick in from the jump:

Stereotype Bias

Stereotype bias is when we assume someone has certain traits because they are a member of a certain group. Interviewers might start to build a mental profile of a candidate based solely on their race/gender/class etc.

Affinity Bias

We tend to gravitate towards the familiar. Sociologist Lauren Rivera interviewed bankers, lawyers, and consultants - who reported that they commonly looked for someone like themselves in interviews.

Confirmation Bias

We have a tendency to search for information that confirms our preconceptions. If you have a feeling that a candidate isn’t suitable based on their CV (which you probably shouldn’t be using anyway), you’re going to be looking for anything that confirms this from the word go.  

How to avoid these interview biases

Use ‘Crowd Wisdom’ to negate interview bias. This is the general rule that collective judgment is more accurate than that of an individual.

We’ve found that having three interviewers is the ideal number. They don’t all have to have equal input into the questioning, but should all be scoring candidates question-by-question (without conferring).

Traditional, unstructured interviews are prone to bias

Most interviews (at least in my personal experience) are go-with-the-flow affairs, where the interviewer explores details they think are interesting, with plenty of tangents and general chit-chat.

Whilst hiring managers might believe their trusty recruiter-senses can spot talent from a mile away, this type of interviewing has actually been proven to be one of the worst predictors of actual on-the-job performance.

Another common faux-pas is over-indexing on education and experience.

Probing candidates on the ins and outs of their experience might seem like the most logical line of questioning, but experience (and education) are both fairly weak predictors of real-life skill.

Asking candidates about their background also invites interview bias.

Bonding with a candidate over the university you both went to or the type of work experience you share isn’t objective assessment - it’s being biased.

Cognitive biases that affect interview questioning:

Halo effect

Our judgment on one particular aspect of something can unduly influence how we perceive other aspects. In terms of interview bias - a candidate can give a good (or bad) answer to a question, which then overshadows how we judge everything else they say.


Individuals may suppress their own objections in favour of group harmony. If you have multiple interviewers, collective decisions may not be as unanimous as they seem.

How to avoid these interview biases

Try structured interviews - ask all candidates the same questions in the same order, scoring them on each question individually. 

Instead of experience-based or ‘tell me a time when’ questions, try posing candidates with a task or problem and ask how they’d tackle it hypothetically. The most predictive questions are those which simulate real-life most closely… are there any parts of the job you could get candidates to have a go at?

You’ll also want to make sure you have scoring criteria for each question. The first stem in fairer interviewing is knowing what good actually looks like so that you’ll know when you see it.

Beware of ordering effects

Even if you were to conduct interviews blindfolded, and avoid all background-related questions, there are still ordering effects that prevent objective decision making.

The order in which you interview candidates affects how you perceive their performance.

A few ordering effects to be wary of:

Decision fatigue

Each decision we make fatigues us, leading to harsher, more risk-averse decisions as time goes on. If you’ve got a day of back-to-back interviews, you’ll likely judge candidates more harshly over the course of the day.

Recency Bias 

It’s easier to recall something that happened more recently. Therefore you might have a better recollection of your most recent interview than earlier ones, for better or worse.

Contrast Effect

The contrast between different things/people can make one seem better/ worse than they actually are. If stronger candidate interviews after a weaker candidate, they may appear more qualified than they really are.

How to avoid these interview biases

If you’re interviewing several candidates on the same day, make sure you’re taking regular breaks.

If your interviews are structured, then each question should be scored individually, against the criteria - you want to score candidates according to your own criteria, not against the previous candidate.

You should also be scoring as you go, or immediately following the interview, so that that you’re forced to try and recall what someone said. 

Download our (free) interview playbook

We broke down our structured process in our interview playbook. Remove interview bias and use predictive, job-specific questions to find the best person for the job, regardless of their age, gender, race, or shoe size.