Cognitive Biases in Web Design

This article is going to explore several cognitive biases in depth and how they are relevant within web design. Cognitive biases impact the way users interact with websites and ultimately how they make critical decisions, such as making a purchasing decision on your website.

Understanding some of the most important principles and applying them within your web design is an important part of conversion rate optimisation.

What is a cognitive bias?

Cognitive bias is the deviation away from rational thinking and rational decision making that ultimately impacts the way individuals do things such as buy, sell, interact with friends, think and feel. Individuals create their own 'subjective social reality' from their perception of the input. It is frequently studied in psychology and behavioural economics.

Why is it important for you as a website owner?

It is very important in web design for several reasons. If you can really understand the brain of your end users, you can ensure you are not presenting information on your website that is sub-optimal and working against your main goals. For example a cognitive bias may lead all users to feel your products are too expensive or that your brand is not trustworthy.

It is important we understand cognitive biases for our own good too, as one of the most common is 'blind-spot bias', where we do not recognise our own biases. Individuals have a tendency to believe they are less biased than the average person.

Cognitive Bias #1: ''Blind-Spot Bias''

Blind-Spot Bias'The Blind-spot Bias is the cognitive bias of only recognising the impact of biases on the actions of others, whilst failing to see the impact on one's own judgement and decision making.

This bias is named after the visual blind spot, the area in an individual's visual field that has a lack of light detecting cells. Studies show that a vast majority of people suffer from blind-spot bias. In fact in a study of 600 residents in the United States in 2015, 85% of people thought they were less biased than the average US resident. The rest of the respondents felt they had an average level of bias and just one thought they were more biased than the average American.

There are number of potential causes of blind-spot bias. In general people like to view themselves in a positive light and biases are often viewed in a negative manner. People also like to feel they are very aware of what is going on around them and the decisions they make. Often this is just simply not true.

Cognitive Bias #2: ''Anchoring''

Screen Shot 2016-03-15 at 21.57.51'This cognitive bias is the tendency to rely too heavily, or 'anchor', on one trait or piece of information when making decisions (usually the first piece of information that we acquire on that subject).'

Many users browse ecommerce websites, or websites selling a service with only a rough idea, or perhaps even no idea at all of what price to expect. Studies show that in such situations, the first price a user sees is paramount to their subsequent price decision and hence acts as an anchor for future prices. For example say a user is browsing a website selling a fairly unique service and the first price they saw was $500, that would act as their anchor when judging how good value other prices are. The 'bias' occurs as users fail to adequately adjust for subsequent information.

Other examples of 'Anchoring' are when visitors to your website have a negative impression of your brand based on word of mouth and reputation. This acts as their 'anchor' and they would be less likely to buy from you.

To make sure anchoring is working for you, as opposed to against you, make sure your anchors are set high. It uses the power of suggestion and gives your on-site customers a frame of reference. The screenshot below shows how prices can be laid out to harness the power of anchoring:

Price Anchoring

Most users will see the $99 price first, which then makes the subsequent prices as you scan right feel much cheaper. Compare this to the reverse order and subsequent prices will feel more expensive.

Cognitive Bias #3: ''Curse of knowledge''

Information Bias

'When relatively well-informed individuals 'fail' or 'fail to be able to' think about problems from the perspective of less-informed individuals, causing comprehension and usability issues'

This bias is really talking about avoiding marketing to yourself and to instead put yourself in the shoes of the less informed. It can become increasingly difficult for experts in a field to explain things in layman's terms. This bias is applicable to many areas in life, but incredibly relevant within web design.

Owners of a website can become so familiar with their own website that they cannot view it in the same way a new visitor would. They are far more likely to use technical jargon and phrases that less informed users simply will not be able to relate to. This really highlights the benefits of web testing to your website, with a fresh pair of professional eyes giving new insight.

Besides rigorously testing your website, other strategies to address this bias include using more 'conversational' web copy, telling stories (studies show our brains remember narratives very easily) and using a diverse range of media (our brains process images sixty thousand times quicker than the equivalent copy).


This article has introduced the concept of cognitive biases and how they can impact the way individuals do things such as buy, sell, interact with friends, think and feel. I have discussed in depth three important cognitive biases and how they can impact you as a website owner.

I will be releasing 'Part 2' of this blog in the next two weeks. Please subscribe to my newsletter if you wish to be notified of this and further future blog posts.


By Samuel Nickson of