Researchers in Sweden and Hong Kong say students may experience a deceptive sense of fluency – AI makes tasks feel effortless
Artificial intelligenceboosts homework scores but cuts exam results by 20 per cent, and this “brain drain” effect takes two years to fully emerge, a new study has found.
Generative AI is rapidly transforming classrooms as much as workplaces, with students increasingly turning to chatbots to draft essays and solve problem sets. But is the technology a personalised tutor or a slow-acting cognitive poison?
Research by scholars from Stockholm University and the University of Hong Kong, who tracked the academic performance of more than 26,000 middle school and high school students across a county in central China over 30 months, offers a quantified answer.
From September 2022 to June 2025, the team tracked homework grades, completion times, monthly test scores and entrance-exam results. By comparing AI users with non-users, they found a clear gap: AI boosted short-term efficiency but harmed long-term learning.
[DeepSeek](https://www.scmp.com/topics/deepseek?module=inline&pgtype=article), ChatGLM, Ernie Bot and
[Qwen](https://www.scmp.com/topics/qwen?module=inline&pgtype=article)emerging as the most popular tools.
Qwen is developed by the cloud computing arm of Alibaba, which also owns the South China Morning Post.
AI use boosted homework scores by 18 per cent and cut homework time from 64 to 45 minutes – a clear productivity leap.
But within six months, the same students’ monthly exam scores had dropped by 20 per cent, and after two years their high-stakes entrance exam results fell sharply, with a 24 per cent drop in the zhongkao high school entrance exam and an 18 per cent drop in the gaokao, or National Higher Education Entrance Examination.