mind games
how language-learning apps use our psychology against us, for us
Knowing more than one language is no longer solely the domain of first-generation immigrants and rich socialites. Independent online language-learning is a big industry, and not just for career advancement — in fact, in our increasingly globalized world, it has never been less necessary to know anything except for one of either English, Spanish, or Chinese. The biggest player in the online language-learning market is Duolingo, an app that claims to teach users a new language with bite-sized vocabulary lessons and a comparatively smaller focus on grammar, conjugation, and language rules and norms. The app feels like a game, with rewards for completing levels lessons, incentives to encourage repeat gameplay learning, and the ability to add and compete with friends for XP — wait, no, it really is XP. The developers have been fairly open about their prioritization of user retention over raw language ability, with the founder even admitting that the app did not intend to teach language to a level beyond early intermediate. At the end of the day, however, Duolingo users download the app because they want to learn a language. Does Duolingo live up to expectations?
To start with, Duolingo has been around for less time than competitor apps, but it holds the largest market share: it was founded in 2011, three years after Babbel and twelve years after Rosetta Stone. While comparisons between each app’s user base would be difficult, as Babbel and Rosetta Stone are intentionally less accessible on mobile and have no free-with-ads tier, these differences are precisely why Duolingo dominates. It has grown large enough to teach languages that by all accounts were very difficult to teach on a mass scale, like Latin, Hawai’ian, Yiddish (beta), and Navajo (beta). It also offers conlangs like High Valyrian from Game of Thrones and Klingon (beta) from Star Trek.
It was founded by Carnegie Mellon professor Luis von Ahn, who also developed reCAPTCHA (that one where you translate squiggly numbers into text or choose all the pictures with buses to prove you’re human and inadvertently train algorithms to read old books). He is also reported to have turned down a job offer from Bill Gates himself. In the past Von Ahn has said that the app’s intention was to give users a more productive avenue for the small free moments in their lives, with a goal to bring them to an early intermediate level of proficiency at best. These days, following the app’s initial public offering, he speaks to investors with more of a focus on data-driven features updates and extensive A/B testing, but the underlying message is the same: user retention is the top priority.
Von Ahn’s emphasis on user retention over knowledge retention dovetails nicely with his candor on the app’s purpose. In his mind, people will feel better about spending their time waiting at the doctor’s office, standing in line, or taking a bathroom break on Duolingo rather than an addictive game that involves no learning; our hustle-and-grind culture is no panacea for this mindset. When even strangers can wax poetic about turning all our hobbies into side hustles and spending their lonesome pandemic days learning to teach yoga and fly planes, it’s inevitable that this attitude will seep into our psyches — and along comes Duolingo to assuage our guilt, the antithesis to Candy Crush with the same psychological rewards and less seizure-inducing colors.
“I’m learning Gaelic,” we smugly exclaim to the office breakroom. What are YOU doing on your phone? is the unspoken undertone.
Psychological cues are baked into Duolingo from the first moment you get a practice reminder email. You made Duo sad, the email admonishes, displaying a large image of a green owl with a single tear rolling down its face. The app uses this external trigger to appeal to your internal triggers and convince you to reopen the app (with a button directly in the email) and get back on track after a period of absence. While it’s not good marketing to associate negative emotions with the service you provide, a little user shaming can go a long way. When you open the app, Duolingo shows pop-ups that offer incentive rewards to make you feel good about getting back to learning. Lessons, especially at beginner levels, take the user on the happy path, simplifying the experience in order to boost the user’s confidence — unfortunately, at the expense of learning. If a lesson is not enough to reach the user’s “daily goal,” a progress bar is shown to remind the user to complete the task (invoking the Zeigarnik Effect).
Duolingo also makes use of smartphone push notifications: users are initially prompted to practice daily at the same time that they practiced the previous day (a tactic called appointment mechanics), reminders which eventually end with a self-filtering “these reminders don’t seem to be working, so we’ll stop them for now” if the app is not opened for many days on end. While some may consider this message condescending, it’s actually a smart move from a user retention perspective: allow users who feel bad every day when they swipe away the practice notification to take a break from the guilt, and their negative feelings will slip away without them needing to deactivate notifications altogether. Then, one day when the unsuspecting former user is just going about their day, Duolingo pops up again to encourage them to try again and has a better chance of resurrecting users.
One of the most ubiquitous Duolingo features is daily streaks: for each day you practice, you extend your streak, represented as a blazing fire emoji that celebrates you after you earn your daily XP (experience points). You can buy streak freezes, but they are expensive; and while streaks are a big reason that people are dedicated enough to race to the nightclub bathroom at 11:56PM to speak to their phone in slow, careful Italian, they are also one of the biggest reasons people quit the app. Losing one’s Duolingo streak is about as devastating as losing a Snapchat streak, except with the added bonus of feeling like you have failed yourself and your intellectual growth. This feature is part of the larger focus on competitiveness and gamification that Duolingo emphasizes above other apps (and that experts say is hindering people’s learning).
For example, another post-lesson pop-up is a challenge to bet fifty gems (the in-game currency on mobile, lingots on desktop) that you can maintain your streak for seven days, utilizing the sunk cost effect at a time where users feel the best about their progress. That allows users to compete with themselves to open the app everyday, and makes them feel bad if they lose the bet. Duolingo also has weekly leaderboards named after different gems (with seemingly no correlation between value and status — Obsidian is a higher rank than Pearl). Users often complain that these leaderboards are overtaken by bots, but even in the event of purely human participants, the ability to compete with unknown players may not be the best motivator; while some will thrive on the competition, others will repeat easy lessons many times over just to earn XP (a trap I fell into more than once), and still others will be intimidated by the idea of needing to put in an hour a day just to stay on track with their peers. On the other hand, some praise the concept of using game-like platform currencies and social-media-adjacent micro-communities to drive engagement and decrease the barriers to entry for a wide range of users.
Duolingo’s icon, a green owl named Duo, is often not discussed except in the context of memes; but its evolution from a clunky concoction of geometric shapes to the cute, minimalist character of today is part of the trend toward gamification. The more childlike an app is, the more accessible and addictive. Serious-looking apps don’t get clicks except from the most dedicated and determined users. But if an app does not appear serious, will we ever seriously learn anything?
These psychological tricks demonstrate that Duolingo, like most “gamified” smartphone apps, has invested significant resources into user retention. These efforts seem to be paying off: Duolingo had a market share of 64% in the mobile language space, the only app to crack the 10% mark. This success, however, has been accompanied by criticism and questions regarding the app’s true pedagogical value — is Duolingo actually helping you learn a language, or is it just a way to feel productive while wasting time on your phone?
The evidence seems mixed. Only about a quarter of users even finish the courses they start. Academic evaluations of Duolingo by linguists have criticized its focus on word-for-word translations — often of absurd sentences featuring (to quote a few famous examples) small-handed presidents and selling one’s mother-in-law for a euro — at the expense of explaining practical everyday phrases and elucidating users on underlying grammatical concepts. Some more informal assessments by users seem to agree: journalist David Freeman described feeling speechless when trying to hold a real conversation in Italian after months of religiously consistent Duolingo sessions; another questioned whether the app’s almost exclusive use of positive reinforcement robbed users of the chance to learn from failures. Duolingo’s English testing service, an additional revenue stream presented as an alternative to expensive exams such as the TOEFL to show proficiency for universities and jobs, has also been described as “woefully inadequate,” lacking rigor compared to the traditional tests which it seeks to replace (despite its ability to be taken from home, which has the benefit of increasing accessibility and lowering costs even further). In particular, experts say that conversing with others is a critical part of learning a new language. While the app did introduce Duolingo Events to allow users to meet up with other learners of the same language in nearby major cities, as someone who actually went to one of them back in 2019, most of the attendees were retirees and very little target language speaking actually took place (though I did make a few French friends). Since the pandemic, Events seem to have transitioned from free meetups to paid classes hosted by uncertified users, albeit with low prices. Nonetheless, hundreds of universities including Yale, Columbia, and Duke now accept the Duolingo English Test as proof of proficiency.
Even critics of Duolingo concede that the app has uses, however. Freeman found that after incorporating grammar concepts from other sources, the wide vocabulary he had learned from allowed him to form sentences quickly without stopping to search for words. Duolingo’s use of spaced repetition has also been shown to increase retention compared to rote memorization. And as mentioned before, the app’s use of mobile game techniques to get users hooked (the company’s Vice President of Product previously worked on Farmville, which gives you an idea as to his expertise) has been remarkably effective at keeping learners committed. The true value of Duolingo may be in providing a sense of progress that keeps learners from giving up on a language altogether, even if fluency requires supplementing the app with additional resources.
One of the key factors that distinguishes Duolingo from other language-learning apps is the freemium model — like almost every mobile game, play for free with ads or pay to “unlock” the ad-free version. In this case, the fee is $84/year for a single user of Duolingo Super (formerly Duolingo Plus). This is the same as the fee for Babbel if you pay for a whole year upfront, and twelve dollars less than Rosetta Stone with the same caveats. While this is a huge (yuuuuge!) factor in the brand’s popularity, it also may correlate with the commitment of users. Free users with no monetary investment are less likely to feel motivated to use the app consistently and properly. However, paid subscriptions are still the highest source of revenue for Duolingo, with about five to eight percent of users paying for premium since 2017.
Duolingo’s shifting business model has also drawn attention. The founders originally envisioned funding the app through crowdsourced translation — learners would be able to translate articles and other written works from English to their target language, with aggregated results sold to the companies’ foreign language editions. However, demand for Duolingo translation never expanded beyond two clients (CNN and Buzzfeed), and the app eventually moved to offering paid English tests as another source of revenue. Language courses, many of which were originally created by community volunteers, remained both free and free of advertising throughout these changes; this came to an end in 2017, when ads were inserted at various points (usually at the end of a lesson). This resulted in a significant backlash from community members who felt it was unethical for Duolingo to begin profiting from volunteer work, culminating in the company offering a $4 million “Language Impact Award” to be divided among the former volunteers. Having moved past the debacle, Duolingo launched an IPO in 2021 valued at $140 a share.
With about $183M in total venture capital support, the app is on a slow but seemingly steady trajectory. Not only are the number of paid subscribers increasing, but significant updates are still rolling out and the team is growing. One month ago, the brand was valued at $6.5B. The fact that the founder did not change his tune about the app’s priority to be more marketable in advance of the IPO is noteworthy (though it should be said that this might have been because most users were not going to look at his comments regarding the IPO, and investors would not care if the app was effective for users, only if it was profitable).
User retention techniques, a seamless mobile experience, and a laundry list of language offerings have made Duolingo a fixture of modern life. If presence in memes is any indication of popularity, the app has been able to insert itself into the cultural zeitgeist. With about forty million monthly active users, its success is undeniable. But it would be foolish to expect that thirty four hours on Duolingo teach as much as a semester of a college class, as the app commonly claims on a mid-lesson loading screen. User retention is completely divorced from knowledge retention; the app has yet to offer explicit feedback on incorrect answers and sufficient implicit grammar instruction. For now, it is on the user to turn the motivation to keep playing into the motivation to learn with concerted external effort. Taking notes, reading books, talking to native speakers, and above all being unafraid to mess up are still the best ways to cement a language in your mind. And if you need a break, enjoy some of Duolingo’s famous absurdist comedy in the form of dad jokes, head-scratching translations, and eerily existentialist observations — because if there’s one thing we’ve learned from Duolingo, users always enjoy an end-task reward (punctuation added for dramatic effect):
“What is tea? What is water? Who am I?” (Hindi)
“I don’t love you, I only love mayonnaise.” (German)
“Danger is my bread and death is my butter.” (Italian)
“I fear royal turtles.” (High Valyrian)
“We got divorced because my cat was too cute.” (Japanese)
“The cow does not eat children.” (Esperanto)
“My computer is the cat’s chair.” (Arabic)
“I am not beautiful, but I am smart.” (Klingon)
“Brains … I need brains.” (Korean)
“My tiger is vegetarian.” (Portuguese)
“I thought it was an apple store, but they only sold computers.” (Swedish)
“The pigs declare war on the farmers.” (Vietnamese)
“Is Finland a meme?” (Finnish)
“I think the woman who lived there died … but it’s a free chair!” (Spanish)
“Everybody wants to find a pink island.” (Turkish)
“Without advertising, this website cannot remain free.” (Dutch)
“I visit the graves and sacrifice.” (Latin)
“The dessert, that’s for me; the check, that’s for you.” (French)
“What is the difference between a man with no dreams and a dead corpse?” (Chinese)
“My buttocks are just lovely.” (Scottish Gaelic)
“The duck swims away when you speak Portuguese.” (Danish)
“Why is there a Norwegian architect in my bed?” (Norwegian)
“We will have grown old by the time you learn Greek.” (Greek)
“People all over the world take showers, and only you do not want to.” (Russian)
“Bob Marley.” (Hawai’ian)
For more, check out r/shitduolingosays on Reddit.