Changing Behaviour

"Although education can open the door to economic opportunity, it is also among the principal sources of inequality: the privileged can get the best education in the world, while those with fewer resources, especially in developing countries, may not be able to get even basic schooling. That is why we started Duolingo. We believe that everyone, regardless of how wealthy they are, should have access to high quality education. And for the first time in history, the technology necessary to enable this is in the hands of billions of people, in the form of a smartphone." Luis Von Ahn, Duolingo CEO

Duolingo Logo transparent PNG - StickPNG


I originally wanted to write about the Duolingo S-1 in the style of some of my previous investment analyses on Spotify, Square and FIGS.

However, when I reflected on why I wanted to write about Duolingo’s S-1 rather than say Blend or Confluent, I realised I’m not interested in Duolingo from an investment perspective today (I wouldn’t buy at the IPO), instead I’m interested in Duolingo’s position as one of the first mobile-first, product-led behaviour change products in the increasingly expensive and ineffective sectors of the economy: health and education.

While these product principles are well-developed in consumer social and gaming, exploring behaviour change in health and education is so compelling because of the positive impact these products can have in people’s lives. That’s why I write so regularly about applying consumer product principles to health and wellness: from addiction management with Arli to anxiety with Calm.

The Rider & The Elephant

Jonathan Haidt’s metaphor of “the rider and the elephant” describes the continual tug of war between our rational and emotional selves. While the rational rider knows what’s good for us, it’s usually emotional elephant that makes the decisions.

This struggle between our minds and our hearts is at the core of research into human behaviour, from philosophy:

“Reason Is and Ought Only to Be the Slave of the Passions” David Hume, On Reason

to behavioural economics:

“Although System 2 (rational thinking) believes itself to be where the action is, the automatic System 1 (intuitive thinking) is the hero of the book." Daniel Kahneman, Thinking Fast and Slow

Although the rider holds the reins and appears to lead the elephant, the six-ton elephant can, at any time, overpower the rider. The rider, although she may not know this, can’t force the elephant to go anywhere unless she motivates her in some sustainable way.

“In order to change the elephant, we have to appeal to a felt need, sparks come from emotion, not information.” Dan Heath

This is why companies invest in brand marketing. Consumers buy from brands that make them feel a certain way — accepted, virtuous, successful. Their emotions determine their purchasing decisions.

While we all know the negative consequences of product designers using their understanding of human behaviour to develop addictive digital products, Duolingo was one of the first to use these models to swing us towards the better angels of our nature.

Duolingo’s Product Philosophy

Make it Easy

“I’m all for empowerment and education, but the empirical evidence is that it doesn’t work. That’s why I say make it easy.” Richard Thaler

From the S-1:

“Low friction. Beginning the learning journey on Duolingo is easy. Learners select the language they want to learn and are asked to indicate a daily learning goal, which can be as little as five or ten minutes a day. They can then choose to start learning a language from the basics or test their existing proficiency to skip ahead in the course. We ensure that our onboarding journey is as intuitive as possible by continually reviewing the actions of new learners as they navigate our app for the first time. We run hundreds of A/B tests to remove friction and make it easier for learners to subscribe to Duolingo Plus.”

In The Messy Middle, Scott Belsky advocates spending 30% of your energy on the first mile of your product. Users need to know why they’re there, what they can accomplish, and what to do next.

Make it Beautiful

“Good design is actually a lot harder to notice than poor design, in part because good designs fit our needs so well that the design is invisible, serving us without drawing attention to itself. Bad design, on the other hand, screams out its inadequacies, making itself very noticeable.” Donald A. Norman, The Design of Everyday Things

From the S-1:

“Beautiful design and engaging storytelling. We focus obsessively on every detail of design. From the precise shape and color of each button to the mood of the celebratory animations that congratulate learners upon finishing each Lesson, our app is calibrated to maximize learners’ delight. Over the years, our owl mascot, Duo, has become a popular brand icon and a marketing asset for our company. In 2019, we introduced an additional cast of characters to the app, each with their own personality and backstory. Our iconic characters now feature prominently in our Lessons and Stories, cheering learners on as they progress. Already, our characters are regularly the subject of “fan art” created by Duolingo learners and shared on social media. We believe that recognizable characters and character-driven storytelling increase learner engagement and stickiness. As our product offering grows to include additional types of learning, our characters will become a common asset unifying the different learning experiences, such as Duolingo ABC.”

The Duolingo app is friendly and intuitive to use. The character animations brings a sense of lightness and fun to an experience that could be considered homework.

Build in Motivation

"Duolingo’s products are built on the belief that the hardest thing about learning a new language is staying motivated. Our product philosophy is centered around ensuring that learners have fun while also achieving their learning goals. We encourage our learners to return to our products day after day through our gamified experience." Luis Von Ahn

From the S-1:

“Motivating game mechanics. Because we believe that staying motivated is the hardest part of learning something new, we focus relentlessly on keeping learners engaged. Features like Streaks and Leaderboards motivate learners to come back to Duolingo every day, and to spend more time learning each time they do. Over 50% of our daily active users have a Streak longer than seven days. And approximately one million learners have an active Streak longer than 365 days, meaning they have used Duolingo daily for at least one year. Launching Leaderboards, which encourage both social connectivity and competition, increased the overall average time spent learning on Duolingo by almost 20%. Ultimately, the high engagement driven by gamification leads to consistent learning and demonstrable efficacy.”

The low completion rates of MOOCs (many <10%) demonstrate that making high-quality education available online isn’t enough to improve educational outcomes. While the Rider may want to learn a new language, the Elephant wants to watch TV. Helping users stay accountable by motivating their Elephants with consistent nudges that highlight status (leaderboards), sunk costs (streaks), and how bite-sized and achievable the tasks are (five minutes a day) is Duolingo’s greatest achievement.

The Outcome

This intense focus on user experience results in better learning outcomes:


And these will only improve as Duolingo uses data from over 2.3 billion tracking events generated every day to inform the more than 500 A/B tests they run per quarter. Each A/B test informs product optimizations and new features that materially improve engagement and learning outcomes.

Behaviour Change for Better Lives

What Duolingo does for learning languages, Perx does for managing chronic health conditions and Whoop does for helping consumers attain peak fitness. I’d love to hear of your favourite products helping change consumer behaviour in a positive direction.

What I’m Reading & Listening To

George the Poet is back. His work pushes the boundaries of the podcasting medium — combining poetry, music and political activism to reach a broad audience and advocate for his vision for the future of Britain.

This graduation speech from 2017, by Chief Justice John Roberts’ at his son’s ninth-grade graduation, is worth sharing. It is both beautiful and unexpected:

“Now the commencement speakers will typically also wish you good luck and extend good wishes to you. I will not do that, and I’ll tell you why. From time to time in the years to come, I hope you will be treated unfairly, so that you will come to know the value of justice. I hope that you will suffer betrayal because that will teach you the importance of loyalty. Sorry to say, but I hope you will be lonely from time to time so that you don’t take friends for granted. I wish you bad luck, again, from time to time, so that you will be conscious of the role of chance in life and understand that your success is not completely deserved, and that the failure of others is not completely deserved either. And when you lose, as you will from time to time, I hope every now and then, your opponent will gloat over your failure. It is a way for you to understand the importance of sportsmanship. I hope you’ll be ignored so you know the importance of listening to others, and I hope you will have just enough pain to learn compassion. Whether I wish these things or not, they’re going to happen. And whether you benefit from them or not will depend upon your ability to see the message in your misfortunes.”

How America Fractured into Four Parts

George Packer at his best, reminding us what non-fiction writing can be.


COURAGE UNDER FIRE: Testing Epictetus’s Doctrines in a Laboratory of Human Behavior by James Stockdale

Reflections on the impact of Epictetus and Stoicism on his time as a POW in Vietnam.

Conscious Culture

The Bolt Financial company culture playbook is now available for anyone to adopt.

“A Conscious Culture is the foundation for everything from the aspirational: Mission, Vision, and Values, to the practical: Hiring, Goal Setting, and Performance Tracking.”