84 cognitive biases that will help you design better-converting products

84 cognitive biases that will help you design better-converting products - the mobile spoon

Please note that this guide now has a second part:
84 cognitive biases to help you design better products - part II

- - -

This one is probably my longest post in my 15 years of blogging, and the result of occasional writing I've been doing in the past few months.

Cognitive biases are systematic errors in our thinking process that affect our decisions making.

As humans, we don’t always see things as they really are, or remember things as they really were. As a result, we create our own subjective social reality that affects our judgment.

As product people, we can take advantage of these cognitive biases to better convey our message and create better converting products, without being evil.

Not in a bad way of course, but in a way that will allow us to get a fair chance to prove that our products are worthy. Products can exploit common cognitive biases to establish trust with the users, improve conversion rates, increase their users’ engagement level, and as a result, improve retention rates.

Because at the end of the day, it’s all in the packaging, and being 100% accurate and concise is simply not enough to persuade the users to give the product a chance or to try out its’ new features.

Users need more than that, and that’s exactly where cognitive biases can (and should) be used.

Now, I have to warn you: this list is freaking long; it includes over 80 different biases - from biases we need to avoid, to biases we can leverage to improve our product's onboarding process, increase conversion rates, improve retention and generate more revenue.

Luckily for you, I created over 40 visual UI/UX examples that will make it easier for you to skim through the list. Oh no, don't thank me! I'm just doing my job...

Who should read this list? 

I believe product managers, marketing managers, and entrepreneurs will find this list extremely useful and relevant, but in fact, anyone who deals with software development might find something to relate to in this list. It helps everyone involved understand the psychology behind users behavior and how to use it to build better products.

Oh, and just to be clear, I did not invent these biases, I just collected them whenever I needed them in my work, and if you happen to disagree with some of them or think they don’t work, that’s probably because you are unique (or you may suffer from the Dunning-Kruger Effect as described below 😉).

OK, that turned out to be a pretty long opening. Let's begin:

Superficial, are we?

The way the information is presented has a big impact on the way we think and make decisions.
Sure, we say we are not superficial, but when it comes to products, the packaging plays a significant role.

1. Streetlight Effect

We tend to search for things where it's easiest to look.
As the joke says: A policeman sees a drunk man searching for his wallet under a streetlight and asks: "is this where you lost it?", and the drunk replies, "no, I lost it in the park, but this is where the light is".
Product tip: Whatever answers you are looking for: product, marketing, user satisfaction, or anything else - dig deeper. Many answers are not where "the light" is, and analyzing data is often much harder than just collecting it.

2. Perceived Value Bias

We perceive the value of a product or service based on how it looks or how it’s served.
As they say: it’s all in the packaging!

Product tip: Design is more important for the success of your product than you probably think.
That extra space, wrong border color, and misaligned text - they all impact your conversion rates.
Make your UI design a priority.

Perceived Value Bias - we perceive the value of a product or service based on how they look
Small UI corrections can make a big impact

Related: my 7 rules for designing a real mobile experience

3. Picture Superiority Effect

Pictures and images are more likely to be remembered than (a thousand) words.
UI tip: Always include images in your content. If you sell products or services - great visuals will improve your conversion rates.

4. Von Restorff Effect (Isolation Effect)

When multiple homogeneous objects are presented together, the object that differs from the rest is more likely to be remembered.

Design tip: Make sure the CTA button stands out using a different style, size, color, and position.

Make sure the CTA button stands out using a different style, size, color, and position.
Make sure your CTA buttons stand out

More conservative than we think

We say we are innovative, we like to try new technologies, but when it comes to core instincts and quick decision making - we aim to minimize risks and stick with the things we're already familiar with.

5. Status Quo Bias

We tend to prefer a status quo over a change.
The current baseline is taken as a reference point, and any change from that baseline is perceived as a loss.

6. Endowment Effect

Once we own something, we value it higher than we did before we owned it.
As a result, we are more likely to retain an object we own than to acquire that same object if we don’t own it.
Product tip: Free trials are the most common use of the endowment effect.
Once users commit to a certain product and invest time in it (i.e. build their profile etc.) it’s harder for them to let go and not upgrade their plan when the trial ends.
Onboarding tip: Find ways for people to play with your product before signing up.
Retention tip: When a customer leaves you, provide examples of all the good things they’ll lose.

7. IKEA Effect

We place a disproportionately high value on products we created (or worked hard for).
Product tip: let your users do something as part of the onboarding process (not too hard, but rewarding) so they can connect with your product.

8. Mere-Exposure Effect (Familiarity Principle)

We tend to develop a preference for things we are familiar with.

UI tip: Stick with familiar UI concepts, behavior, terms, signs, and icons.
Be consistent across your marketing materials, website, and product to optimize the funnel.

UX Writing tip: Align with the industry jargon. Make sure your users feel comfortable.

Stick with familiar UI concepts, behavior, terms, signs and icons.
Stick with the standards 

9. Functional Fixedness

We tend to use objects in the traditional way they were used.
Usability tip: When your product challenges an existing usage tradition - it may cause some usability challenges. Keep them in mind and try to solve them in advance.

10. Law of Instrument (Maslow's Hammer)

We tend to over-rely on tools we are familiar with, even in the presence of much better options.
As they say: “To a man with a hammer, everything looks like a nail”.


Don’t call me a loser

We hate losing more than we like winning. The right message (at the right timing) might turn on this aversion and push us to make a biased decision.

11. Loss Aversion

We prefer not to lose $100 than to win $100 because the value of losing something is higher than the value of getting it (which is pretty consistent with the Endowment effect described above).

UX Writing tip: Use negative terms to express the potential loss: “stop wasting money”.
Product tip: Limit your special deals (inside and outside your product) to create a sense of urgency: “this exclusive deal ends in x hours”.

Help your users avoid losses

12. Zero-Risk Bias:

We love certainty even if it's counterproductive.
Product tip: offer money-back guarantee and risk-free trials to reduce the level of risks and make your customers feel secure.

Make sure all possible concerns are addressed

Related: 10 lessons we learned (the hard way) when we asked our customers to pay...

13. Neglect of Probability

When we are under pressure, we fail to think of the probability of risks to happen.
As a result, minor risks might get overrated or neglected.
Product rule: during a conversion funnel - the smallest uncertainties might cause the user to mistrust your product and stop. Make sure all details are clear and presented upfront.
Especially the ones that involve money such as the total cost, discounts (if exists), additional costs.

Neglect of Probability - Make sure to remove uncertainties in your product
Clear uncertainties proactively

Check out the YOUR most popular posts in here: 
The best of the Mobile Spoon 

14. Scarcity Effect

We place a higher value on an object that is scarce and a lower value on an object that is highly available.
The fear of missing out (FOMO) makes us more vulnerable to temptation and impulse and pushes us to make rash decisions.

Product tip: decorate your products and services with “limited time offers”, “limited quantity”, etc
Create the impression that many others are watching this item “right now!” and about to grab the last remaining items any minute.

Creating scarcity effect in UI - the mobile spoon
Scarcity effect in action

Or, as Booking.com would probably do it:

Scarcity Effect - the drastic approach (as can be seen in well-known hotel booking apps - the mobile spoon
Scarcity effect - decepti.com style :)

15. The Simulation Heuristic

We determine the likelihood of an event to happen based on how easy it is to picture the event mentally. As a result, "near misses" are more disappointing than other failures.
Product tip: Send a “You’re almost there!” email to users that almost completed an important action in your product, but eventually didn’t. Let them know they are very close, and that the opportunity is still waiting for them.

[Read: Is 'the fold' still a thing in today’s scrolling and skimming culture?]

Disproportionately emotional

We try to make rational decisions, but sometimes our emotions are just stronger than we think.

16. Negativity Bias

We give more weight to bad experiences than we do to good ones.

1 Negative Emotion = 3 x Positive Emotion

Negativity Bias: 1 negative emotion equals 3 positive ones - the mobile spoon

Product/marketing tip: Illustrate your product value by the negative experience it resolves.
If you hope your story to make an impact or even go viral - try emotionally negative content.

Negativity Bias - Illustrate your product value by the negative experience it resolves - the mobile spoon
Illustrate the value of your product by emphasizing the negative experience it resolves 

17. Base Rate Fallacy (Base Rate Neglect)

We tend to ignore general information and focus on specific cases.
How to use: don’t just share cold information about your product. Instead, show testimonials, use cases, from people or companies others can relate with.

Work-related tip: If you want to be more convincing - blend your quantified data with some individual stories. Use quantified data to support your opinion rationally. The specific examples will convey your message emotionally.
If you want to be more convincing - blend your quantified data with some individual stories. Use quantified data to support your opinion rationally. The specific examples will convey your message emotionally.


18. Identifiable Victim Effect

We tend to empathize more with a specific individual than with a largely anonymous group.

How to use it: When you are telling the story of your product, use personal stories of individuals instead of generic statements.

Identifiable Victim Effect - Use personal stories of individuals instead of generic statements.
Use personal stories instead of generic statements

19. Likability Effect

We like people who like the same things we do.
As an example, if you were to tell me you’re a Transformers fan - I would immediately count you as a friend.

Marketing tip: Show the strengths of your product by using testimonials of customers who faced similar issues as other potential customers.
Make sure to use the authentic language customers are using - say it in their own words.

20. The Focusing Effect

We attribute too much weight to events of the past and translate them into future expectations.

21. Impact Bias

We tend to overestimate the length or the intensity of future emotional states.
It’s the “I’ll never get over her!” bias.
Possible usage: Paint a picture of the users without your product or service, and later, introduce your product with how it will solve those pains.

[Read: 40 rules for designing and writing text in mobile apps]

Easily convinced

The art of persuasion! Here are some (cheap?) tricks to help you better convey your message.

22. Anchoring Effect:

We tend to rely too heavily on the first piece of information presented to us (the “anchor”) to make subsequent decisions.

How to use it: The oldest trick in the book: you add a high price as the anchor and then cross it out and set a much lower price next to it.
Looking at how Steve Jobs used it with the iPad launch I must ask: did it really work?

Anchoring Effect - Performed by Apple's Steve Jobs during the iPad launch
Steve Jobs demonstrating the Anchoring Effect

Beautiful stuff... and here’s my take on the Anchoring Effect:

Anchoring Effect Example - The Mobile Spoon
Anchoring Effect in product pricing

23. Hyperbolic Discounting

We prefer an immediate payoff (even if it’s small) rather than a larger-later reward.

Tip: Offer a small discount (or free shipment) for immediate purchase, rather than a larger discount for future purchases.

Hyperbolic Discounting - Offer small discounts for an immediate purchase - the mobile spoon
Offer small discounts for an immediate purchase 

24. Social Proof

If people like us are using it - it must be good!
How to use it: Social proof is a great way to build trust. Here are a few examples that can be used in your website, App Store product page:
  1. Well known customer logos
  2. Well known partner logos
  3. Testimonials and authentic recommendations by customers (from the target audience)
  4. Counters (number of customers, deals, sessions - whatever works)
  5. Media mentions and quotes (“as seen on…”)
  6. Awards by well-known organizations (i.e. hottest startup by WIRED)
  7. Certifications
  8. Links to case studies with actual numbers

Social Proof - Build trust using counters and customer logos - www.mobilespoon.net
Social Proof - Build trust using counters and customer logos

Don’t say: “we are awesome because… “, and instead, let others testify:

Social Proof - Don’t say “We are awesome because…” and instead, let others testify. www.mobilespoon.net

25. Authority Bias 

We attribute greater accuracy to the opinion of an authority figure and be more influenced by that opinion (even if the subject is unrelated to the person’s authority).
How to use: Build your authority by promoting your famous references:
  1. Contact influencers and give them free access to your product or service
  2. Highlight famous customers or brands
  3. Testimonials by famous people and celebrities
  4. Use authority figures in your visuals and statements (i.e. doctors, professors, etc.)

Authority Bias - Promote your strongest references

26. Bandwagon Effect (Herd Behavior)

We often do things only because “everyone is doing it!” (Ketogenic diet anyone?).
We change our opinions, according to the number of people thinking the same way.

Marketing tip: convince that everyone is using your product and more people will indeed use it.
Bandwagon Effect - Convince that others are using it
Bandwagon Effect

And here’s another example for the using the Bandwagon Effect in your product:

Bandwagon Effect - The “Most Popular” Example (the mobile spoon)
The “Most Popular” example 

27. Belonging Bias

We are all social creatures and in order to feel part of a group we often act like other members in that group. If all the software developers are using Slack - you probably should too, right?

Copy tip: Use counters such as the number of customers, sessions, services provided, to convince the audience that your product is a standard.

28. In-group Bias

Once we are part of a group, we almost “automatically” favor members in our group over members in other groups.

In-group favoritism also means we help members of our group more often than those in other groups.

In-group Bias - the mobile spoon

29. Not-Invented-Here Syndrome

We avoid using (or buying) already existing products, because of their external origins, and prefer to invent similar products internally.
Example: When your engineering team prefers to develop something from scratch instead of using an existing product.

Management tip: Tackle this phenomenon by complimenting your team. Their expertise is needed to develop the core of the product and their precious time cannot be “wasted” on side modules, or services that are already invented by others.

[Read: 11 lessons learned while trying to become a data-driven company]

30. Belief Bias

We are more likely to accept an argument that supports a conclusion that aligns with our prior knowledge while rejecting counter-arguments to the conclusion.
Writing tip: When talking about the benefits of your product - don’t exaggerate.
If it’s too good to be true - people will not believe it.

31. Foot-in-the-door Technique

A small agreement creates a bond between us and the requester and potentially makes it easier for us to agree on bigger agreements.

Subscription tip: Give your users a free trial to hook them up with something small.

Onboarding UX tip: Don’t overwhelm the user with over-complicated onboarding tasks.
Break it into small/easy chunks to achieve small wins and keep the user happy and engaged.

Foot-in-the-door Technique - Make onboarding easy by creating “small wins"
Achieve small wins during the onboarding process 

32. Variable Reward

Our joy from getting rewards increases when the rewards are unexpected.

Product tip: Hook your users with daily offers, free bonuses, reputation points, prizes and more. 
The more “action” you create on a daily basis - the more your users will feel connected and hooked to the product.

Variable Reward - Hook your users with daily offers, free bonuses, reputation points, prizes and more.
Hook your users with daily offers, free bonuses, reputation points, prizes and more 

Check out the YOUR most popular posts in here: 
The best of the Mobile Spoon 

Not as rational as we think

Make rational decisions is not as easy as it seems.

33. The Gambler's Fallacy

We mistakenly believe that if something happens more frequently than normal during a given period, it will happen less frequently in the future.
Work-related tip: Stick with facts. Less intuition, more numbers.

34. Confirmation Bias:

We seek and favorite information that confirms our initial belief and preconception.
Question: Did you ever manipulated your KPI reports, again and again, switching from weeks to months, from months to quarters, until finding the conclusion you were looking for?

35. Disconfirmation Bias

We tend to dismiss evidence that refutes our beliefs.
Question: Did you ever like a candidate (during a job interview) so much that you ignored some warning signs?

[Read: 5 product management lessons I've learned when moving from B2B to B2C]

36. Framing Effect

Our decision-making processes are not always as rational as we think and we are influenced by the way the information is presented (positive vs negative frames).
Product tip: In most cases, positive frames (i.e. glass is half full) convert better.

Framing Effect - Try to present the full half of the cup for better conversion
A positive frame in action 

37. Context Effect

Our perception of things is influenced by the context in which they are presented or happening.
In visual design, a color or a size of an object can be perceived differently depending on where and how they are presented.

Context Effect in UI design

38. Selective Perception

Our perception of things is highly influenced by our expectations.
Product & marketing tip: Your product’s conversion funnel doesn’t begin when the user boards, it begins when the user sees your ad for the first time.
Misalignment between the marketing message and what the product delivers will disappoint your users and result in poor conversion rates.
Aligning the messages across all media (and stages of the funnel) will bring users with the right expectations and as a result - improve conversion rates.

39. Hot-hand Fallacy

A fallacious belief that a person who has experienced success has a greater chance of further success in additional attempts.
How to use: Emphasize a list of successful stories to build your strong brand.

Hot Hand Fallacy - If Ashton Kutcher invested in this startup it must be good, right?
If Ashton Kutcher invested in this startup it must be good, right? 

40. Anticipation:

Our brain is wired to anticipate positive experiences. Anticipation contributes to our happiness.
Examples: Waiting a few months for a big vacation contributes to the overall experience. Buying early tickets to Avengers: Endgame makes us all excited and happy.
Product tip: Create anticipation for your new product (or release) by announcing it ahead of time. Create a positive buzz, something to look forward to, ensuring your audience will remain excited.

41. Information Bias

We seek information even when it cannot affect our actions.
Product tip: When presenting products or services (on your website or within your product itself) - make sure to include photos of a detailed description. The more information you can pile on to product description, the greater the assurance your users will get.

Part II

That's it for this part of the cognitive biases collection.
Make sure to visit the second part of this incredible guide for plenty of more design snippets and practical examples.

84 cognitive biases you should use to design better-converting products - part 2

Follow me on twitter @gilbouhnickor subscribe to my newsletter to get some occasional posts directly to your inbox.


Gil Bouhnick The Mobile Spoon
Anonymous said…
Good post. I absolutely appreciate this site.

Keep writing!
Gil Bouhnick The Mobile Spoon
Brad said…
This is a must, for every marketer out there.
Gil Bouhnick The Mobile Spoon
Unknown said…
This comment has been removed by a blog administrator.
Gil Bouhnick The Mobile Spoon
Unknown said…
Long read, but it was so worth it. Thanks for all this nice info!
Gil Bouhnick The Mobile Spoon
Anonymous said…
I could not refrain from commenting. Perfectly written!
Gil Bouhnick The Mobile Spoon
Alon said…
This is really a great read!
Gil Bouhnick The Mobile Spoon
Mark said…
This list is incredible!
Please turn it into UX Cards.
Gil Bouhnick The Mobile Spoon
Anonymous said…
Therefore, it doesn't matter whether you're advertising your product or service or not, what matters presently will be the
amount of cash you happen to be spending on this occasion and so on the quantity and
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is often a special kind of position, which includes become professional anyway nowadays.
Gil Bouhnick The Mobile Spoon
This is gold, thanks a tone for writing this 👍
Gil Bouhnick The Mobile Spoon
Anonymous said…
I take an issue with some of the microcopy (such as on the loss aversion point) which is borderline unethical and emotionally manipulative in its entirety. For better conversion rates a better approach would be to highlight value rather than make the user feel bad/anxious/stressed.
Gil Bouhnick The Mobile Spoon
Really thankful for your work! Well done! I took note of all of it - one by one.
Gil Bouhnick The Mobile Spoon
Anonymous said…
Some good advice here, but quite a few of these are dark patterns and borderline unethical practices that designers should refrain from using.
Gil Bouhnick The Mobile Spoon
Anonymous said…
Point 84 can't be true: it doesn't rhyme.
Gil Bouhnick The Mobile Spoon
Nelson Bibby said…
Really good reading. Thank you.
Gil Bouhnick The Mobile Spoon
Alisha said…
This is so great!
Gil Bouhnick The Mobile Spoon
Anonymous said…
Insane post! Love it!!!!! 💚
Gil Bouhnick The Mobile Spoon
Liad said…
Soooooo long but I didn't want it to end!
Gil Bouhnick The Mobile Spoon
Anonymous said…
This is, hands down, the best guide on this topic. 👌🏿
Gil Bouhnick The Mobile Spoon
Anonymous said…
I every time spent my half an hour to read this blog's articles every day along with a mug of coffee.
Gil Bouhnick The Mobile Spoon
Unknown said…
This is good article. The longer the better it is awesome
Gil Bouhnick The Mobile Spoon
Maggie said…
This is by far the most amazing guide on this topic.
Gil Bouhnick The Mobile Spoon
Pierre said…
Waw, great peace of content ! I printed it to read and re-read as much as possible. Very nice job !
Gil Bouhnick The Mobile Spoon
Travel Desire said…
amazing content! I read it again and again and will come again. It shows the effort you put in this article.
Gil Bouhnick The Mobile Spoon
Mirza said…
Amazing work!
Can i use it to redesign and post on my linkedin! make it easier to understand.
I will give credit to you.
Gil Bouhnick The Mobile Spoon
logo designing said…
Thanks a lot for sharing us about this update. Hope you will not get tired on making posts as informative as this.
Gil Bouhnick The Mobile Spoon
Anonymous said…
for users, some "tricks" are annoying or even disgusting.👎
Gil Bouhnick The Mobile Spoon
Thank for very nice this sharing.