In two recent landmark cases, social media companies were found liable for harming children; Meta and Google are appealing and deny that their products are addictive. Still, more than a decade of research has identified key app features designed to hold children’s attention and keep them using apps longer.
Cultural anthropologist Natasha Dow Schüll, who studied video slot machines for 15 years, says these design elements act like “superglue.” They were refined in casinos and later migrated to phones and tablets, appearing across social media, games and streaming platforms. Combined, they can pull users into a dissociative, trancelike “machine zone” or “dark flow,” where people lose track of time and self.
Schüll found four core features responsible for that pull:
1) Solitude
When interaction is just between you and the device, social cues that might prompt stopping disappear. Kids using screens alone—often in bedrooms—are more likely to develop problematic use, continuing despite harms to sleep, school or friendships.
2) Bottomlessness
Apps remove natural stopping points by delivering endless content: videos that autoplay, infinite scrolls, continuous feeds of photos and comments. Without a finish line, there’s no sense of completion.
3) Speed
Faster feedback—quicker scrolling, instant new content—deepens engagement. Schüll’s gambling research showed that faster play extends sessions; the same principle applies to apps. High-speed internet and interface design amplify this, making it easier to merge with the screen and remain in flow.
4) Teasing (almost-getting-what-you-want)
Algorithms are adept at guessing what a user seeks, but they withhold full reward. Instead of delivering exactly what you want, apps present something close enough to keep you searching. That intermittent, escalating promise—“almost” finding the desired content—encourages prolonged use because there’s always the possibility the next item will be the payoff.
These elements work together as a recipe for overuse. Solitude removes social brakes; bottomlessness erodes stopping points; speed accelerates immersion; teasing sustains the chase. While harmful to many adults, the combination is especially risky for children, who are more vulnerable to persuasive design and less able to self-regulate.
Schüll suggests using these features as a rubric: parents can rate apps for solitude, bottomlessness, speed, and teasing to judge potential harm. Beyond individual regulation, Schüll and neuroscientist Jonathan D. Morrow argue that children need both help managing device use and protections from harmful design built into products.
Michaeleen Doucleff, a longtime science journalist with a Ph.D. in chemistry, is the author of Dopamine Kids.