Why you want what you can’t have: the psychology behind great apps - Part 1
Insights and examples from leading apps to optimise user interaction, engagement and retention.
I’m the third child in a family of four, and when we were young, my mum always used a simple trick to make us finish our plates: “It’s the last one.” Automatically, we would ALL want it. It could be anything, and it would always work.
Fast forward to 2016, I was a young, inexperienced product manager at Streetbees.
Streetbees is a market research company. We had a mobile app where users answered questions and surveys, and we used machine learning to analyze responses and provide insights for large FMCG companies.
My challenge?
Getting users to stick around and complete more surveys.
As a fresh product manager, I decided to look at what competitors were doing. I noticed that many were adding the number of spots left on the app and, without thinking twice, added it as well. We saw an improvement in our metrics; more users were starting surveys. I didn’t think much of it and moved on.
A few years ago, I had an Aha moment when I read “Nudge.”
The authors worked in the Obama administration to promote policies that help individuals make better choices while respecting their freedom. They made small changes that had a huge impact. I loved it and then read more about behavioural economics and cognitive science.
Suddenly, I realised that many of the changes I had implemented in the apps I worked on relied on cognitive biases and specific design principles. It was an aha moment, and I began writing about these biases and how they are used.
In this two-part series, I’ll break down key cognitive biases and design principles that can transform user experience, with examples from companies like Wise, Revolut, and leading consumer apps.
We’ll explore concepts like progressive disclosure, the labour illusion, the curiosity gap, scarcity and loss aversion to help you ethically attract and retain users more effectively.
The power of cognitive biases and design principles
What are cognitive biases?
Every time users interact with your product, they:
Filter information
Seek meaning
Act within a given time
Store bits of the interaction in their memories
Let’s look at Wise, a company that makes sending money abroad cheaper and easier. When a user lands on Wise, they go through several phases:
Filtering Information: Users are presented with options like sending money, receiving money, or checking exchange rates. Their brain filters what’s most relevant at that moment.
2. Seeking Meaning: If they choose to send money, they need to understand how it works. What’s the exchange rate? How fast will the transfer be?
3. Acting Within a Given Time: Whether they’re in a rush to send money to family abroad or paying for a service, time is essential.
4. Storing Information: Each step leaves a trace, building trust and loyalty, ensuring users come back. Given that users tend to evaluate an experience based on the peaks and the end of the experience, Wise adds an animation when a use completes a transfer that works as a memorable delighter.
Many people have an aversion to administrative activities like banking because they are complex, lack transparency, and mistakes can have significant consequences. Making it easy for people to understand and take action is crucial, and understanding cognitive biases and design principles can help achieve that.
Examples of cognitive biases and design principles
Let’s examine the definitions of various cognitive biases, design principles, and examples of them in successful apps to better understand where they come into play:
Progressive disclosure: An interface is easier to use when complex features are gradually revealed later.
Curiosity gap: Pique users’ interest by providing just enough information to intrigue them, but not enough to satisfy their curiosity immediately.
Scarcity: People place higher value on items or experiences perceived as rare or in limited supply.
Labour illusion: Intentionally make certain processes appear longer or more effort-intensive than they technically need to be to enhance the customer’s perception of their value.
Loss aversion: People prefer to avoid losses more than earning equivalent gains
Progressive disclosure
Definition
Users are less overwhelmed if they’re exposed to complex features later. Therefore, an interface is easier to use when complex features are gradually revealed later.
Example
Most online games use that UI principle to engage new users. Initially, the game starts with simple levels that act as a tutorial, teaching players the basic mechanics with easy-to-complete stages that provide a quick sense of achievement and encourage continued play. As players advance, the game gradually introduces new types of obstacles. This steady increase in complexity keeps the game challenging without being overwhelming, ensuring that players stay engaged as they adapt to each new element and develop new strategies.
Similarly, Revolut, an online banking app, uses the same principle. They understand the user’s intent by asking what they want to use Revolut for during onboarding and then use that information to personalise the experience by showing the most relevant features first before introducing others. When the user lands on the app for the first time, they only see three tabs: Home, Transfer, and Hub.
Additional features such as Invest, Crypto, and Lifestyle are gradually introduced.
By revealing complexity at the right moment, you keep users engaged instead of overwhelming them.
📩 Next week, we’ll continue with more cognitive biases, including labour illusion, the curiosity gap, and scarcity—and how top apps use them to drive engagement.
Misbehaving looks like an interesting book, added to my reading list!
Love this photo of your family!