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Conversion Psychology – Theories on user psychology

As we look at different theories of user psychology, hopefully you will begin to see the overlap between them and their overlap with the cognitive biases and impacts on reasoning discussed in previous articles.

Perhaps no one theory is perfect, but when we view them as a collection, they provide us strong guidance about how to increase conversions using psychology.

"Old Brain" / System 1


The idea behind the Old Brain theory (sometimes known as system 1 thinking) is that we have a primitive way of thinking and a more advanced one.

The old brain is given its name as it is believed that these systems are more strongly associated with survival (and therefore developed earlier in human evolution).

The “new brain” (or system 2) was developed later, and is involved in higher reasoning and logic.

We use both systems to make a decision about whether to make a purchase or not, but are more likely to use our “old brain” rather than the new brain when making a decision we can act on right now.

Old brain vs new brain

If the purchase is a considered one we are aiming to make in the future, then the logical, fact-finding system comes into play more. But if the decision is about something we could do right now, then the old brain has much more sway. 

Examples of old brain driven decisions would be buying a bottle of wine on offer near the self-checkout in the supermarket, or buying a birthday present that you left to the last minute with Amazon prime.

Examples of new brain driven decisions could be choosing which new laptop you want (so long as yours is still working), or picking a user research agency to help you understand your customers better.

But even in the seemingly logical decisions, the old brain still plays a vital role.

Take emotion for example, one of the key contributors to decision making allocated to the old brain. When the ability to process emotion is damaged due to brain injury, it has been shown to leave people struggling to make even the most logical of decisions.

Relevance to conversion

The more we can tap into the old brain way of thinking, the more we can encourage decision making and a resulting conversion. People make faster and more decisive decisions when using the old brain than the new.

The new brain is actually ineffective at decision making, despite the fact we often cite logical reasons for our decisions. This is because humans are not rational, we are rationalisers. We make a decision, and then seek to justify that decision, rather than making a decision based on all available evidence.

This makes sense as “all available” evidence is likely to be a huge amount in many cases. We couldn’t possibly make a fully informed decision, and so must rely on our old brain to help us choose.

Even if what you are selling is a considered decision (such as a B2B offering), you will need to tap into some old brain thinking in order to get someone to convert. Otherwise, your potential customer would just spend forever weighing up their options.

Once we have chosen, we are likely to view our choice as the correct one due to choice supportive bias and Cialdini’s commitment/consistency principle (see below). These impacts on decision making suggest we are more likely to be consistent once we commit to something.

We may even discount new information that contradicts our decision as it causes cognitive dissonance. We justify our decision, because being wrong doesn’t feel very good.

This means that if you can get a conversion by triggering the old brain, customers are likely to return.

Wider psychological connections to old brain thought processes


The idea that the old brain prefers the uncomplicated could be extended to the wider user experience.

Usability focuses on making it easier for the user to move seamlessly through the user flow, such as making it as easy as possible for a user to get from an ecommerce homepage to the thank you page after checkout.

Increasing usability links with the ideas of reducing the number of “brain cycles” the user must go through (Fogg behaviour model) or the “friction” they experience (MECLABS Institute conversion formula). As we reduce the amount of effort it takes to complete a task, people are more likely to do it.

Paradox of choice

Previously, we have talked about the paradox of choice, and how presenting users with too many options can result in them not being able to make a decision at all. This can help us understand how over complexity is the enemy of old brain decision making.

We suggested reducing the number of options or directing attention to particular options to reduce the amount of work they need to do whilst making a decision.

Reducing the amount of effort the user must go through to make a decision also reduces the number of “brain cycles” (Fogg behaviour model) or “friction” (MECLABS Institute conversion formula) that causes task abandonment.

When we aim to reduce the paradox of choice, we are aiming to reduce the extent to which the new brain gets involved in decision making. We are encouraging a decision based on old brain factors, such as feeling emotionally reassured by a socially approved choice due to the belonging and conformity principles.

Getting the attention of the old brain

1. Tangibility

Tangibility (or simplicity) is important to the old brain. Easy to understand concepts and words work better than those which make people work to understand them, as the harder your brain has to work, the more it has to engage higher level thought processes (new brain thinking). This is similar to the Fogg behaviour model’s assertion that increasing the number of “brain cycles” reduces ability.

Tangibility is linked to the idea of cognitive fluency, a preference for easily grasped concepts and a bias against things that seem complicated due to an association with risk.

Cognitive fluency is said to be more important when the user is in a negative frame of mind than a positive one. When we are unhappy, we seek out the familiar as it is safe. When we are happy, we are less likely to become anxious when presented with a challenge.  

If something is easy to understand it is likely we have come across it before, and therefore we are familiar with it. We need to pay it less attention, the familiarity bias kicks in, and we feel more positively towards it.


Try the following to trigger the old brain through tangibility.

  1. Simplify copy to make it easier to understand; for example, “lose weight” may work better than “optimise your BMI”.
  2. Use metaphors and similes to explain unfamiliar concepts.
  3. Use an easy-to-read font to make what you are saying appear easier to understand.
  4. Simplify complex processes using visual step-by step instructions. (This also has the benefit of increasing user self-efficacy, or belief that you can achieve something).

2. Visual

Images are processed quicker than sound or text, and they can also be more effective at conveying meaning. As the saying goes, an image is worth a thousand words.


If possible, always use an image to increase understanding, such as screen shots of the process, or images of the product or service in use. Your customers should be able to explain what your website is about seconds after seeing the main image above the fold (where the page cuts off once it has loaded).

Visuals can also be used to convey emotion. You should aim to use visuals to tap into the emotion you want users to be feeling at every stage of the user journey.

3. Contrast

People respond to contrasting images and statements as it helps them make a quick decision. A lack of contrast can lead to confusion, mental effort, boredom, and a more considered, lengthy decision-making process.

However, our brains are designed to detect difference, change of state or novelty, as difference could be a threat. Whilst too little variety can cause a lack of engagement, too much contrast can overwhelm a user with negative emotions, making it important to get the balance just right.

Contrast is strongly linked to cognitive bias of perceptual incongruence, which is where visual data doesn’t match up with what is expected, as this forces the brain to pay more attention to the source of conflict.


Increase contrast on your website:

  • If suitable, use before and after or with and without pictures to convey benefits.
  • Use a contrasting colour to the background for CTA buttons.
  • Use different background colours to denote different sections of copy.
  • Use alternating pictures and text to break up long sections of copy.

4. First and last

According to old brain theory, the brain will pay attention more to the first and last thing it experiences. This means the start and end of videos, copy, and overall customer experience are hugely important and will be what people remember the most.

However, the first and last principle conflicts with the peak-end rule which states that people remember the most emotionally important part of their experience and how their experience ended more strongly than the beginning and end.


One thing both of these theories agree on is that how you end an experience matters. Aim to make the end of your user’s online experience and the end of the customer journey (if this is different) a great one.

Due to short attention spans online, it makes sense to build your “peak” emotional experience early on. For this reason, I suggest placing your primary benefits or reasons to engage first.

5. Emotion

Emotive images or sales copy capture the old brain’s attention far better than a well laid out, logical argument.

Evoking an emotion which matches the emotions felt by the reader can make conversions more likely, but evoking an emotion which does not match the user’s emotion can do the opposite.

Additionally, a bad emotional experience after a conversion can result in lost opportunities for repeat business. According to the peak-end rule and the first and last principle, it is best to end the user journey on a high note.

For example, I personally love that every order I place from Qwertee (a geeky online clothing store) comes with a small pack of sweets. It costs them hardly anything, but I look forward to it and it acts as an added bonus to receiving my order.


Copy aimed at conveying an emotional benefit should make the reader feel better about themselves. If you are evoking a negative emotion (such as anxiety or sadness) to stress a pain point, you need to balance this with a solution which evokes a more positive emotion (such as accomplishment or reassurance).

This is important, because without doing so, the user will feel overwhelmed by their negative emotions. This is unpleasant and results in a lack of self-efficacy and denial (leaving your site to push the negative emotion away).

The images you use, the words you say, the colours, and even the font you use will give off an emotional cue. In order to tap into emotion fully, you need to pick the ones which convey the emotion you want users to be feeling.

You should also think about the whole user journey, and how emotion plays a role in this – especially if you want those repeat sales.

Emotion and the connection to hyperbolic discounting

Hyperbolic discounting is not a cognitive bias that comes up regularly in our work. But it does help us understand the old brain versus new better and the power of emotion to sway our decision making.

Hyperbolic discounting states that when a potential benefit can be gained now (there is a possibility of immediate gratification), we are more likely to choose that option than a delayed gratification (even if the delayed reward is higher).

This explains why people will often choose to pay for a service monthly rather than annually, even if they could afford the annual payment by saving up a little longer before subscribing to whatever it is.

People’s decision making becomes increasingly led by new brain thinking if there is no possibility for immediate gratification. So, if instead of having access to that service now, you could either save up and pay for 6 months of the service, or save and pay for a year of the service (at a discount), you are more likely to wait until you can afford the cost of the service for a year.

There is no benefit to you right now, so you are less emotional and more rational in your decision.

To trigger the old brain and encourage conversions now, it makes sense for subscription companies to offer their service monthly (with immediate access) as well as at a discount for the year. Not presenting an immediate option could result in the user forgetting, or moving on to a competitor.

6. Self-centredness

Being called self-centred is usually an insult. But the reality is that most of us are more self-centred than we are selfless.

This isn’t our fault, it’s nature. Almost every living organism on the planet could be considered self-centred to some extent as even those without a brain strive for their own survival over the survival of others.

Claude C. Hopkins also recognised the importance of speaking to the selfish side of our personalities in his copywriting principles and several cognitive biases are based around our self-centred tendencies.


So, you know your users are self-centred, but why should you care? How does that get you more conversions?

Well, because users are interested in themselves (not your company). They are more likely to respond to copy which stresses the emotional and practical benefit to them. So, instead of saying why your company is different, you should be telling your users how that difference is going to help them.

You should also aim to use any cognitive bias or impacts on decision making that play into the user’s focus on themselves and their decisions. This includes evoking a sense of belonging (their emotional need to belong to a group in order to feel happy), as this is something that is likely to be important to most.

Other cognitive biases related to a user’s self-centredness are:

  • The Forer / Barnum effect.

    The tendency for people to resonate with vague descriptions of their personality and therefore feel as though you are speaking directly to them.

  • Cognitive dissonance.
  • Self-generation effect.

    This describes how people feel more positively towards something they created (provided they believe they were successful), valuing it more than something they didn’t.

    If a person comes up with an idea, works something out, or creates something for themselves (and believes they are successful at this), they feel more positive about it, value it more, and are more likely to remember it.

    To harness the effect, allow users to tailor your product or service. If they put effort into making the product or service right for them, they will be more invested in seeing it through to purchase.
  • Self-generation memory effect.

    Similar to above, people are more likely to remember something if they came up with the idea.

    Using a feedback tool to ask users why they are interested in your service or product encourages them to come up with their own reasons to buy. Not only do you get insight into user motivation, you also help users focus on this and remember what benefits they see in your product or service.
  • Endowment effect.

    The Endowment effect states that people place a higher value on items they own than those they don’t. Some research suggests that owning an item can create a link between the item and a person’s identity, especially if the item was instrumental in helping the individual overcome an unpleasant experience.

    Offering free trials, a free returns policy, and warning people what they will lose out by ending their relationship with your company could help you obtain and retain customers.

It’s also important to recognise that prospective customers may value their current choice highly due to choice supportive bias, cognitive dissonance and loss aversion bias.

Cialdini’s 7 principles of influence

Cialdini’s 7 principles of influence describe the ways people are orientated to act in certain ways.


The idea of the reciprocity principle is that people do not like to feel indebted to others and will feel obliged to help people who have helped them out. So, by giving your users something, they feel obligated to do something for you in return. The eventual goal is that reciprocity will result in conversion.

Examples of practices based on the reciprocity principle are offering some free help and advice in return for sign-ups to a course or program, and producing enjoyable video content in return for Patreon memberships.  

The more personal you can make the act of giving, the more likely it is that the reciprocity principle will kick in. After all, would you feel more indebted to a website providing free CV writing tips, or to a friend who gave you tips relevant to your CV?


If you offer a service, producing content around this service can help you with conversions (yes, I acknowledge the awkwardness of this sentence!)

If you offer software, then free trials can be effective (but this is also due to other factors such as loss aversion).

And for ecommerce? Free gifts can help encourage impulsive (and therefore higher value) sales, especially if they are unexpected. 


People are more likely to be consistent (to continue doing something) once they have made a commitment to start it. This is why asking for non-commitment heavy information on a web-form should be done first.

Once people begin to fill out a form, they are likely to be consistent in completing it. So, asking for someone’s email address should come before asking for their phone number or credit card information.

People are also more likely to be consistent if they have made a public commitment, such as posting about a viewpoint or sharing content from a company on social media.


To use this principle:

  • Get people to commit to undertaking a small task before asking for something big.

    An example of this is allowing users to download something in exchange for an email address. Then sending them marketing about your core offering, which encourages them to use your paid services.
  • Encourage people to like and share social content.

Social proof

People are more likely to follow the crowd than deviate from it because there is less risk involved.

The impact of social proof is amplified if the user identifies as similar to those who have already taken action due to the unity principle (see below), or belonging and conformity principle.


  • Use product badges on ecommerce collection pages which say “Customer Favourite” (or similar).
  • Display the number of customers served (McDonald’s used to do this, and it didn’t work out too badly for them!)
  • Show users how many other people are interested in an offering (think hotel booking websites which tell you how many people have viewed the same hotel in the last hour).
  • Display genuine testimonials which appear trustworthy (include names, titles, and photos if you can), and make sure these address a problem the target audience can relate to.
  • Make product reviews easy to filter so users can find information that is relevant to them quicker. Shopify apps such as allow this kind of functionality.
  • Showcase any awards or praise in publications.


People are more likely to accept and believe a statement if it comes from a place of authority. Although “authority” may conjure images of noted academics, people with any great power over the decisions that a section of the population make could be said to be an authority figure. This is why social influencers are, well, influential.


Who is deemed worth listening to will be different for each target audience. You need to select authority figures to represent your company that your target audience look up to.

The authority principle is linked to the social proof principle above, in that people will place more value on social proof from those they respect. For example, even if a user doesn’t know the person that wrote a testimonial on an agency website, if they have a relevant and impressive job title, the testimonial will be more persuasive.

However, the ultimate goal is for your company to become a face of authority for your target audience. This way your influence is completely under your own control.


The liking principle states that people are more easily persuaded by those they like. This principle comes into effect more when a user is dealing with an actual person, rather than a faceless company.

The degree to which the liking principle comes into play will largely depend on how hands-on employees are. That being said, a person can “like” one company more than another, so there is definitely value in trying to get users on your side.


Depending what industry you are in, you can try some of these strategies to harness the “liking” principle of persuasion:

  • Ensure all initial communications from service-based companies leave a positive impression.
  • Demonstrate great customer service when someone has a question.
  • If something goes wrong, make sure the person who deals with it leaves the customer happy.
  • Add a strong “about us” section which humanises the company and makes employees relatable.


Scarcity is a limited number of the thing that is desired, and urgency is when there is a limited amount of time left until the thing that is desired disappears.

Scarcity and urgency help encourage fast action to avoid losing out. They can therefore be an implementation of the “action” stage of the AIDA copywriting formula.

The need to act fast encourages users to forgo using the new brain and make a decision based on the more impulsive old brain criteria. Scarcity and urgency are also an implementation of loss aversion bias.

Unity (us vs them)

Unity is a more intense sense of connection than just “liking”.

Using this principle means getting customers to strongly identify and define themselves as being within a certain group. This principle plays on human nature’s need to “fit in” and belong (often to the extent of excluding others).

It is a common persuasion principle used in politics to create division and unquestioning partisan loyalty. However, it can also be used to bring people together for more positive purposes.

Unity can increase the likelihood of conversion as unity is associated with “group think” and copycat behaviours (conformity). So, if you can target a united target audience and your company is adopted by that group, it is likely that conversions will climb.

The unity principle relates to the belonging and conformity principle. Many of the ways to implement it are the same. In brief these are:

  • Get your target audience to self-identify through social proof.
  • Use personalisation to reinforce the idea that your company and the people who buy from it are in the same group when you have a varied target audience.
  • Align your values with those of your target audience.
  • Create a community.

Claude C. Hopkins’ original copywriting principles

Although Hopkins’ principles are quite old, and some might say outdated, the advice given is familiar (or at least it will be if you have read our other articles on user psychology). It therefore holds weight in the realms of user psychology.

Be specific

Copy should be specific about the value the company delivers as generalities are unbelievable and untrustworthy. This Hopkin’s principle relates directly onto the specificity and ambiguity aversion principles.

Being specific is important as ambiguity and untrustworthiness can increase risk. Although risk aversion varies person-to-person, it is best not to trigger the anxieties that a lack of specificity creates, as according to the MECLABS Institute conversion formula, anxiety can prevent conversion.

Offer a service

Hopkins believed that people are innately selfish, so you must sell the benefit of what you do for your customers to your prospective customers.

According to Hopkins, some of the best adverts present what appears to be an altruistic service as there is no initial cost associated with it.

The principle of offering a service is closely linked to triggering the old brain through self-centredness, and to the numerous cognitive biases linked to our selfish tendencies.

Tell the full story

Copy should cover everything users need to know, whilst remaining succinct and readable.

Even when engaging our new brain, we are influenced by how difficult it is for us to absorb information. This dislike for long copy relates to lower conversions due to:

An example of a way to cover the main things a user may want to know whilst remaining succinct is using comparison tools.

As some decisions do engage the new brain more, users will want a way to easily compare their options. Whether it is choosing a new washing machine or a used car, tables which allow for easy comparison on a few key pieces of information can increase conversions.

Comparison tools which allow the user to further refine information by what they are really interested in can be particularly helpful. 

Be a salesman (person)

Hopkins believed that copy should be written like a genuine conversation with a single human being.

This makes sense in the wider context of what we know about conversion from Cialdini, as we are going to “like” a company represented by someone who appears genuine and informed much more than a company with no “human” quality.

That's all for now

Whether you scan read, skipped to the important bits, or read it in full, I am grateful for the time you have given to this article. Admittedly it was a long one, but hopefully you found it encouraging and useful.

Do you find user psychology interesting?

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When you work with us, we have regular discussions about how we can improve your website. Psychology is baked into our recommendations, and we are always looking for opportunities to get great clients on board and talk about it more.

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