2026-09-08 / Signal #4
Students who use AI for schoolwork score ~1.5 years worse, OECD PISA 2025 finds
“The students who didn’t let the chatbot write the essay are the ones who can still pass the test.”
The Story
In the world’s largest 15-year-old assessment, students who never or almost never used AI chatbots to draft or summarize schoolwork outperformed daily users by about 28 points in science after socioeconomic adjustment—roughly a year and a half of schooling. The gap held for writing and research tasks; moderate “help me learn” use was the exception. Nearly half of OECD students use AI at least weekly.
Why It Matters
Culture, identity, and institutions—kids outsourcing the muscle of thinking while the test still measures it. Concrete global dataset, not punditry.
Evidence
OECD PISA 2025 results + Bloomberg / TNGlobal summaries of the science-score gap.
Sources
Daily scan: 2026-09-08