The folk psychology is settled: short-form video is rotting our brains. The evidence is not. Hana Kiros, an assistant editor at The Atlantic, argues that the distance between the two — between what nearly everyone suspects about TikTok and what anyone has actually measured — is the real story, and that the gap does tangible work: it shields the platforms and leaves governments legislating blind.
She begins with the worry itself, from people with some standing to have it. Andrew Garfield, promoting a film in which a London couple move their tech-dependent kids to a barn without electricity, described himself to Variety as addicted to an Instagram feed of “weird ceramics” and Japanese craftspeople: “I’ve given all of those hours to nothing. It’s genuinely enraging because we don’t have as much control over these impulses as we should.” Steve Chen, a co-founder of YouTube — the platform that hosts plenty of recycled TikTok on Shorts — has said he is wary of his own children watching much short-form video, because of what it does to attention. Kiros adds the ordinary version: emerging from a scroll gone too long, she worries her thoughts will permanently become as flighty as her feed.
Why the research doesn’t exist
Very little is known about what short-form video does to the human mind, and the absence is structural rather than merely negligent. Human-subject studies are slow and expensive, and academics are reluctant to spend years investigating apps that may be irrelevant by the time the results appear. The federal government has not prioritized funding research on potentially addictive behaviours, gambling and social-media use included. The obvious candidate to fill the gap — the industry, which holds exclusive and valuable user data — has no incentive to bankroll research that might show its most profitable products cause harm, and has largely kept its internal work private.
What does surface tends to arrive through litigation. A sloppily redacted 2024 complaint in a lawsuit against TikTok revealed internal research allegedly finding that compulsive usage “correlates with a slew of negative mental health effects like loss of analytical skills, memory formation, contextual thinking, conversational depth, empathy, and increased anxiety.” TikTok said the documents were outdated and the quotes cherry-picked. Kiros’s framing is that short-form video marks how far behind cognitive research sits relative to the pace of new technology, and that the not-knowing supplies executives with a ready defence — causation is hard to establish for any single app or feature.
A viral study that measured swiping
Much of the public research is flimsy, and Kiros spends real space on the clearest example. A study at China’s Zhejiang University went viral: 56 young adults clicked through short videos — not on social media — while lying in an MRI machine. Two brain regions involved in cognitively demanding tasks were more active when participants swiped away before a video was halfway through than when they watched to the end. Prominent accounts, including the prediction market Polymarket, promoted it as further proof that TikTok makes people smooth-brained; one outlet ran the headline “Instagram Reels & TikTok Make You Dumb & Depressed.”
Multiple neuroscientists told Kiros the study said nothing about short-form video, intelligence, or depression. What it found was that brain areas involved in taking action lit up when a participant chose to take an action — skipping to the next video. It lacked controls, equated finishing a video with enjoying it, and never established the baseline against which the supposedly video-addled activity was being compared.
The better studies, and their ceiling
The stronger work points the same direction as intuition. Researchers at the University of Bristol concluded last year that the constant context-switching inherent to short-form video may degrade prospective memory — recalling something you had previously intended to do. Caty Enders, a doctoral student at the University of New Mexico, found that students who used TikTok at high volume had more trouble with working memory and episodic memory. A 2024 study at Sigmund Freud University in Austria found that participants reporting more than four hours a day showed neurological activity indicating cognitive abnormality.
All of it comes with caveats, and Kiros is careful with them. Even the best studies tend to be small and preliminary; Keith Robert Head, of Capella University, who recently published a review on short-form video and attention, could point to just four good studies conducted in the United States. Most of the research comes from China, and Enders warned against carrying findings across, given that American platforms face far less government control, collect more user data and personalize feeds more aggressively.
The mechanism is also unresolved. Is the harm specific to the medium — an overstimulating stream of non sequiturs and bright visuals with no natural stopping point — or is it displacement, with hours on TikTok crowding out sleep and everything else? On the second reading the videos are no more inherently harmful than binging Friends. Participants in Enders’s TikTok-and-memory study averaged 133 minutes a day on the app. “If you do anything every day for 133 minutes, it will change you,” she said.
What the vacuum costs
For Kiros the uncertainty is not grounds for calm. It relieves pressure on platforms to make targeted changes, and it leaves policymakers working without information: several countries have already imposed blanket social-media bans on minors on imperfect data, which she calls a poor basis for restricting civil liberties. Everyone else is left with an ambient, unverifiable sense that the apps are bad for them.
She grants the perception its own weight. That so many people suspect a problem with short-form video may itself be reason for alarm. Luiz Pessoa, a neuroscientist at the University of Maryland, accepts the literature’s limits and still thinks an attention epidemic is plainly underway — he and his teenage daughter watch Formula 1 highlight reels together, and while they do, she is also on her phone. “It’s obvious we’re multi-, triple-, quadruple-tasking in ways that at least 20, 30 years ago we weren’t.” You do not have to be a neuroscientist to suspect your brain can be stretched only so thin.