A randomized study involving over 1,000 students has been conducted examining the relationship between ChatGPT usage and critical thinking, originality, and student performance on university assignments

A randomized study of more than 1,000 students examines ChatGPT, critical thinking, originality, and student performance on a real-world university assignment.

https://openai.com/index/what-students-gain-from-chatgpt-critical-thinking-training