Harvard study: human expert peer review comprehensively loses to Claude, with an error rate nearly 3 times that of AI

A study by Gary King and Steven Worthington of Harvard University shows that in a review comparison on the same 124 papers, Claude Opus 4.8 comprehensively outperformed paid human experts. GPT-5.5 served as judge in the experiment; humans did not win once in the overall comparison, Claude led in all seven dimensions, with an average score of 8.7 versus 6.0; 3 former journal editors chose Claude in 26 of 30 blind selections. Sentence-by-sentence verification against the original manuscripts found that 15.9% of human comments were judged incorrect, versus 5.5% for Claude without internet access. The researchers also conducted ten types of robustness checks, including word-count alignment, rewriting the style, and cross-model mutual judging, and the direction of the results did not change. The two recommend that journals publish official AI review prompts, and that authors use AI for pre-review before submission and attach responses, arguing that publication decisions could be shortened from months to days.