A/B testing is a powerful tool that can enhance user experinces. In this piece, we’ll explore how you can take this to new heights by applying our special sauce: human behaviour and psychological principles. 

Understanding A/B Testing

A/B testing, also known as split testing, involves comparing two versions of a webpage, email, or other digital asset to determine which performs better. We typically split their audience into two groups, exposing each to a different variant (A and B). The variant that provides the best results becomes the benchmark for future iterations, helping refine and optimise digital strategies.

While A/B testing traditionally focuses on metrics like click-through rates and conversion rates, integrating a psychological perspective adds depth to the analysis. By considering user behaviour, emotions, and decision-making processes, we can gain valuable insights into the why behind the data.


Understanding User Behaviour

A psychological approach helps decode user behaviour. By examining how users interact with different elements of a webpage, we can identify patterns and preferences. For instance, does a specific colour scheme evoke trust or urgency? Does the placement of a call-to-action influence engagement? These insights guide design choices for a more user-centric experience.

Discover how we apply behavioural science with marketing via our whitepaper.


Psychological Theories

So let’s take a look at what theories we can use to help maximise your A/B testing experiment results:

Colour Psychology: This theory looks at the study of how different colours affect human behaviour. According to a study conducted by Joe Hallock, blue is most commonly associated with trust and security. When asked which colour connotes trust, 34% of those surveyed responded blue. Similarly, 28% of people voted blue when they were asked which colour they associated with security. The study also found that people associate blue with reliability and dependability. 

A way to apply this theory in A/B testing is to test how different colours affect behaviour. For example, you could test a black “add to cart” button vs a red “add to cart” button. Fashion brands such as Zara & Ted Baker opt for a black button as black has connotations of luxury, whereas a red button has connotations of action and speed. Red is also associated with discounts and sales so it is important to ensure that your “add to cart” button has the correct connotations for how you are trying to position yourself in your market. 

Scarcity Effect: The scarcity effect suggests that people assign more value to opportunities when they perceive them as scarce or limited.

To see if this theory exists with your customers you can experiment with variations that highlight limited-time offers, low-stock warnings, or exclusive deals to trigger the scarcity effect and observe the impact on user engagement and conversions. ASOS do this really well with their ASOS premier discounts, including the message “hurry tho, this deal ends soon!” encourages their customers to act now so that they don’t miss out on the deal.

Oglivy used the scarcity effect to increase sales of KFC french fries by 56% just by simply nudging customers to buy by changing the messaging to “$1.00 french fries won’t be around forever.” Given the uncertain offer duration, people rushed to grab KFC's $1 fries, recognising the undeniable value. The limited availability made the fries even more tempting, creating a sense of urgency.

Social Proof: suggests that people tend to follow the actions of others in an attempt to reflect correct behaviour. Social proof elements for a company would be reviews, testimonials, user ratings, awards etc. 

To test this theory you could try adjusting where your reviews sit on your site, if they are right at the bottom of the site vs if they are front and centre for a customer to see. 46% of consumers feel that online business reviews are as trustworthy as a personal recommendation from a friend or family. This highlights the importance of having your reviews available for customers to read and check before they purchase. You could also test what format the reviews are in e.g. written reviews and star ratings. Also, it shows how many people are viewing a product, how many people have it in their basket, how many people have purchased in the last 24 hours etc. There are so many different ways that you can use social proofing to help encourage conversion. 

Anchoring: Anchoring is a cognitive bias where individuals rely heavily on the first piece of information encountered, the "anchor", when making decisions. A way that Anchoring is used effectively is during sale periods, for example, Black Friday.  As soon as you have a “was” price you have anchored the customer that they are getting a cheaper price than what it normally costs. Boots do this successfully when they offer discounts. They show the “was” price, and how much the customer is saving. This helps the customer understand the deal they are getting. 

Framing Effect: The framing effect demonstrates how the way information is presented (framed) can significantly influence decision-making. A way to test the framing effect is to experiment with variations of how the information is framed such as emphasising benefits vs risks or gains vs losses. This will help you to understand how framing impacts user perceptions and choices. 

The above example, when you compare the two options, 20% fat sounds like an unhealthy option so you would choose the 80% lean option. When in reality, there is actually no difference between the two products but one sounds more appealing than the other due to the framing effect. 


Maximising Results

While A/B testing alone is a great way to see what resonates with users - applying a psychological approach and taking a continuous improvement mindset will allow you to take your marketing campaigns to new heights; reaching new audiences and increasing conversions. 
Plus, by applying behavioural science to your testing approach you’ll learn more about your audience's behaviours, emotions, drivers and how these affect the decision-making process for your services/products. 

If you’re thinking about how you can apply psychological principles and A/B testing to your next campaign, please get in touch - our team would love to hear from you!





Sophie aims to bring value to every client she works with. To help develop marketing strategies that amplify the client's brand. To build relationships with the clients so that they feel that they can trust the agency to deliver excellent work so that they can succeed in their industry.

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