11 April 2024 | Dr Jo Kandola

What is unconscious bias?

Unconscious bias is possibly the most misunderstood of all the biases, but tackling it is key to ensuring better decision-making, more successful hiring and fairer treatment of under-represented groups.

Imagine a river flowing through the countryside. The course of the water is influenced by the things we can see – like the curve of the banks, the reeds growing at the sides or the islands in the middle – but it’s also affected by unseen currents and the contours of the riverbed that lies beneath. This is very much how our minds operate. As well as the things we’re consciously aware of that steer our decisions and behaviour, there are other unseen factors exerting a powerful influence over us that we’re completely unaware of. These ‘below the surface’ things are our unconscious biases.

Bias is essentially how our brains streamline our thinking so that we can make sense of the world around us. It’s impossible for us to process all of the information that we receive, so our brains categorise things into neat packages to help us make sense of things quickly. These categorisations are driven by learning how things are associated with each other in our environment.

For example, through exposure to a cow we would learn to associate certain things with cows, such as milk, grass, or the colours black and white. While these mental shortcuts are helpful in enabling our brains to conserve energy and process things quickly, they also lie at the root of much of our bad decision-making and unfair treatment of other people.

The science of bias

Our brains use two different types of processing: System 1 and System 2 (Kahneman & Frederick 2002; Stanovich 1999).

System 1 thinking occurs almost effortlessly and allows us to quickly assess and react to the world around us. System 1 thinking is associative, meaning that it connects ideas, concepts, and memories instead of trying to interpret every experience from scratch, and it activates categories that simplify and structure the information we receive. This can be an advantage, such as enabling us to spot and react quickly to danger, but it can also lead us to jump to conclusions about people or situations without us being aware of it – and this is the source of our unconscious bias.

System 2 thinking is slower than System 1. It’s conscious and logical and kicks in when we’re doing things such as analysing information, solving problems or making mathematical calculations – but our System 1 thinking can still come into play. When it comes to making decisions under pressure, for example, research (Bodenhausen et al., 1999; Wilson et al., 2000) shows that our ability to engage in System 2 processing is considerably reduced – opening the way for biases to creep in. Even when we think that we are being rational and objective, our System 1 beliefs and biases can still affect many of the decisions we make. Understanding how these two systems work together can lead us to a better understanding of unconscious bias and how to mitigate its impact.

Types of unconscious bias

There are several types of unconscious bias and they can often overlap with each other. Some of the most common are:

Affinity bias, or similar-to-me bias, where we prefer people who are like us in some way or with whom we feel some kind of connection.

Confirmation bias, where we favour information that confirms our existing beliefs or values while ignoring or downplaying information that contradicts them.

The halo effect which occurs when a person’s positive qualities in one area influence our overall perception of them – for example, perceiving someone to be intelligent or kind because they are physically attractive.

The horn effect, when someone’s negative qualities in one area lead to an overall negative perception of that individual.

Bias round age, gender and race where we allow stereotypes and unconscious attitudes to influence our opinions of people based on specific characteristics.

How unconscious bias affects our behaviour and decisions


As soon as we meet someone new, we’re starting to put them into a box. Researchers at Harvard have found that the two things we first notice about a person are their race and their gender. This means that whether we like it or not, from the moment we come across someone new, our brains are already starting to apply what they ‘know’ about men and women, or about groups of people from a particular ethnic background. The subconscious assumptions that we make around things like someone’s gender, race, disability, age, religion, sexuality or social background can severely cloud our judgement and prevent us from seeing that person as a unique individual – with damaging consequences.

The impact of unconscious bias in the workplace

We may be blissfully unaware of our unconscious biases, but their real-world impact can be deeply felt. Unconscious bias can lead to unfair and discriminatory outcomes in many aspects of our lives, including education, healthcare and criminal justice, and its impact in the workplace can be profound.

Unconscious bias can have a profound impact at every stage of the employee lifecycle, from the recruitment process and selection through to promotion and career advancement, training and development and identification of leadership potential, and even who exits an organisation, for example through redundancy. Left unaddressed, it can mean that organisations struggle to attract and retain talent, make bad hiring decisions, get rid of the wrong people, fail to spot risks or take advantage of business opportunities or lack the agility to adapt to a changing world.

Gender bias in the hiring process


Consider a hiring manager who’s interviewing people for a leadership position. In spite of thinking he’s being fair and objective, the hiring manager is being influenced by societal stereotypes and by his idea of what a ‘leader’ looks like, which is typically male. As a result, he may overlook highly capable female candidates in favour of less suitable male candidates.

Gender stereotypes can also play into our unconscious bias and what we think men and women are intrinsically ‘good’ at. By way of example, in spite of face-to-face auditions typically resulting in a higher proportion of men being selected for orchestras – as late as 1970, only 5% of the members of the top 5 US orchestras were women – a study of orchestral auditions showed that if candidates were invisible to the appointment panel and performing behind a screen, and with the panel forced to decide on merit only, women were selected equally.

Age bias in task allocation

Imagine a situation where younger employees are repeatedly assigned to the innovative, high-profile projects while older employees are routinely given mundane and unchallenging tasks.

Without realising it, the leader assigning tasks may be unconsciously making decisions based on stereotypes associated with age, such as that younger employees are more tech-savvy and adaptable and older employees have poor tech skills or are resistant to change. Left unchecked, this would limit opportunities for professional growth and fail to tap into the diverse skills and experience of older staff.

Similar-to-me bias in networking opportunities

Consider an industry where networking is crucial for role progression but where most people in senior roles are white and from a private-school background. People naturally gravitate towards those with similar backgrounds, interests, or demographics, known as similar-to-me bias, and as a result may overlook or exclude those who are different in some way.

This could mean that professionals from a minority ethnic or underprivileged socio-economic background are overlooked for mentorship opportunities or find it hard to access professional networks, resulting in limited opportunities for progression, collaboration, and innovation.

Race bias in interview candidate section

Bias around race can come into play without us ever setting eyes on someone. Recent studies around recruitment have shown that we can make sweeping assumptions about someone based on their name alone, with job applicants with a ‘white’ sounding name like ‘John Smith’ being 50% more likely to make it to the interview stage than applicants with non-white sounding names – even when their resumes are identical in every way.

The upshot of this is that many employers are ruling out excellent candidates without ever giving themselves the chance to prove themselves at interview. This deprives the organisation of the much-needed experience and talent that comes from diverse team members and potentially loses skilled people to their competitors.

The impact of unconscious bias on individuals

One study found that of those who reported experiencing unconscious bias at work:

  • 33% felt alienated from their colleagues
  • 34% actively withheld ideas and solutions
  • 80% would not recommend their employer to others.

Consider the impact of this for a moment. Someone experiencing unfair treatment resulting from unconscious bias is likely to be disengaged and demotivated and feel little inclination to make suggestions, help their colleagues or put in extra effort. They’re more likely to take time off sick or with stress, and they may even decide to leave the organisation altogether and post negatively about it on social media or online job forums.

Multiply this by every employee affected by bias in your organisation, and immediately you’ve got a significant risk of absenteeism, low productivity, high employee turnover and a potential drop in the quality of service for clients and customers, not to mention the risk of significant reputational damage to your organisation.

Unconscious bias, in short, is costing us money.

Tackling unconscious bias

Unconscious bias is deep-seated and can be challenging to address. After all, none of us likes to think we’re biased. If asked, we’d probably rate ourselves as fair and inclusive and say that we don’t see things like race or disability or gender and treat everyone equally – but the simple truth is that we don’t.

To combat unconscious bias we need insight and action. Using tried-and-tested behaviour change methodology, Kandola+ Unconscious Bias training provides learners with data-driven insights into their biases and creates personalised bias-busting action plans that are easy to implement and proven to deliver results. This can help us gain a better awareness of our unconscious biases and start to address them. Contact us to find out how we can help you tackle unconscious bias in your organisation today.