None of the studies we have read shows this, and none measures intelligence. Asked whether these tools can be said to make us "dumber", the authors of "Your Brain on ChatGPT" answer "No!" and ask that such words be avoided; they do, however, infer from their results a likely decrease in learning skills, in a study of 54 people that has not yet appeared in a peer-reviewed journal. In a trial run at 1 high school in Turkey, classes that revised with an AI that answers freely scored 17% lower in the exam than classes without AI, while an AI that gives hints produced no measurable difference.
Read the source article: AI impact on the brain: what 3 studies show, and their limits