AI chatbots outpersuaded elite human debaters by producing more claims faster
A preprint covered by Science placed more than 2,000 people in political debates with other people or leading chatbots. ChatGPT, Gemini, and Claude consistently changed opinions more than laypeople and a paid group of 56 elite debaters, including world champions. The models' advantage was not a mysterious new form of wisdom. Persuasion rose with the number of fact-checkable claims, and forcing AI to write human-length messages at human speed brought its performance down to roughly human levels. That mechanism should alarm anyone building political, commercial, or therapeutic chatbots: claim volume can look like evidence even when the facts are weak or false. The researchers also found professional fundraisers were less effective than a persuasive bot at increasing donations in the study. These are controlled experiments with paid participants, not proof of mass persuasion in the wild, but they expose a scalable asymmetry between the speed of assertion and the time humans need to verify it.